subject:"\[EVDL\] Recommendations for push mower motor\?"

EVDL Dave R.,

Comparing on a weight basis $/lb (on the theory that weigh goes with Pb
content which goes with quality of design and manufacture and looking at $/
Ah:

*#113lb* $3.46/lb @ $45 17.2 Ah  *$2.62/Ah*
http://www.atbatt.com/genesis-np18-12-12v-172ah-sealed-lead-acid-battery-with-nb-terminal.asp?cr_brand=BB&cr_product=BP17-12#specifications
*Is this the "Hawker Genesis" you were talking about?*

*#214lb* $3.57/lb @ $50 21.6Ah *$2.31/Ah*
this one weighs an additional pound for $5 more:
http://www.atbatt.com/power-sonic-psh-12180nb-fr-sealed-lead-acid-
battery.asp?cr_brand=BB&cr_product=BP17-12

*#314.1lb* $4.15/lb @ $58.5 22Ah *$2.63/Ah*
http://www.atbatt.com/amstron-12v-22ah-electric-vehicle-agm-battery-nb-terminal.asp?cr_brand=BB&cr_product=BP17-12#specifications

*#414.4lb* $4.38/lb @ $63 18Ah *$3.50/Ah*
http://www.atbatt.com/bb-bp18-12-12v-18ah-agm-battery-w-nb-terminal.asp?cr_brand=BB&cr_product=BP17-12#specifications

*#514.5lb* $4.96/lb @ $72 20Ah *$3.60/Ah*
http://www.atbatt.com/bb-battery-hr22-12-sla-battery.asp?cr_brand=BB&cr_product=BP17-12

*#615lb *$6.60/lb @ $100 20Ah* $5.00/Ah*
http://www.atbatt.com/bb-evp20-12-12v-20ah-agm-battery-w-nb-terminal.asp?cr_brand=BB&cr_product=BP17-12

Raises all sorts of questions...

Is #3 lying about the Ah?  Does the low weigh really me it is not as good
as say #5 which weighs a 180 grams more for an additional $14 each?

On a pure money for performance basis one of the lowest weigh, least
expensive #2 seems like a good deal.  Can 21.6Ah be believed?

Is there any merit at all to buying #6?  Its price point looks terrible,
but on the weight theory is is best.

This is a great way for me to learn here, if you all are willing to chime
in...

Mike


On Tue, Apr 29, 2014 at 1:11 PM, EVDL Administrator  wrote:

> On 29 Apr 2014 at 12:06, Lee Hart wrote:
>
> > I have Enersys, Hawker, and Concorde AGMs that are now over 10 years old
> > and still delivering at least half of their original capacity. I also
> have
> > Gates, and Deka gels just as old that are still usable.
>
> I just recently retired the last of a batch of Hawker Genesis AGMs that
> dated from about 1997.  They were (well-) used when I got them.
>
> Of 24 equally old Deka Dominator gels, I'm still using 16 (and a couple
> others sit around).  Most have 60-90% of their rated capacity.
>
> One of the things I like about these batteries is how low their self
> discharge is.  They need only very infrequent charging when in storage.
>
> David Roden - Akron, Ohio, USA
> EVDL Administrator
>
> = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
> EVDL Information: http://www.evdl.org/help/
> = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
> Note: mail sent to "evpost" and "etpost" addresses will not
> reach me.  To send a private message, please obtain my
> email address from the webpage http://www.evdl.org/help/ .
> = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
>
>
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> http://groups.yahoo.com/group/NEDRA)
>
>


-- 
Put this question to yourself: should I use everyone else to attain
happiness, or should I help others gain happiness?
*Dalai Lama *

Tell me what it is you plan to do
With your one wild and precious life?
Mary Oliver, "The summer day."

To invent, you need a good imagination and a pile of junk.
Thomas A. 
Edison

A public-opinion poll is no substitute for thought.
*Warren Buffet*

Michael E. Ross
(919) 550-2430 Land
(919) 576-0824  Google Phone
(919) 631-1451 Cell
(919) 513-0418 Desk

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Re: [EVDL] Recommendations for push mower motor?

18Ah BP17-12


On Tue, Apr 29, 2014 at 2:27 PM, Lee Hart  wrote:

> Michael Ross wrote:
>
>> my power supply allows me to tell it a peak current and peak voltage...
>>
>> It sounds like I can safely set the voltage to 28.8V and 4 amps, and
>> not be concerned if I forget for a few days.  Do I have that right?
>>
>
> What is the amphour capacity of your batteries? 28.2v and 4a is OK for
> maybe a day, but not for days. At 28.2v, plug the power supply into a timer
> and set it to shut off in 16 hours or so.
>
> If you have to leave it on for days, set the voltage for no more than
> 27.4v (13.7v per 12v battery). That is a relatively safe long-term voltage.
>
>
>  If I am in a hurry, I could wait for 28.8V, then perhaps set it a 30V and
>> 1Amp?
>>
>
> 30v and 1 amp max is OK for an hour or two at the most. That will equalize
> the batteries.
>
> It all depends on how much babysitting you want to do. Probably the
> simplest way is to get one of those 12-hour timers that install in a light
> switch box, normally used to control a bathroom fan or outdoor yard light.
> For example, an Intermatic FF12HC etc.
>
> http://www.intermatic.com/Products/Timers/InWallTimers/
> Springwound_Auto-Off_Timers/FFCommercialSeries/FF12HC.aspx
>
> To charge:
>  - Plug your power supply into the timer.
>  - Set the timer for 12 hours.
>  - Set the power supply for 28.8v and its maximum current.
>  - Wait for it to shut off. The batteries are approximately 100% SOC.
>
> To equalize:
>  - Charge as above. Then...
>  - Set the timer for 1 hour.
>  - Set the power supply for 30v and a maximum current of 2% of the
>battery's amphour rating (i.e. 0.4 amps for 20 amphour batteries).
>  - Wait for it to shut off.
>
>
>  I could rig up a JLD 612 temperature controller to be a minder and shut
>> off
>> the charge at 100F or so.
>>
>
> When a sealed battery gasses, it heats up and pressurizes the case. If it
> charges too long, or at too high a current, it blows the vents open, and
> loses water. That's bad for life.
>
> The heat also shortens the battery's life. As temperature rises, the
> battery voltage falls. This makes it draw more current, which causes more
> heating... This is called "thermal runaway", and leads to destroying the
> battery. A good charger has temperature compensation to detect the
> temperature rise, and turn down the voltage or shuts off to prevent this.
>
>
>  I could also mange it for temperature and use a plain old 10A 12V charger
>> with the cell paralleled.  Does this idea have merit/
>>
>
> If that "plain old 12v charger" is any good. Many of them are nothing but
> a transformer and rectifier in a box. No voltage, current, or time control
> at all.
>
> --
> If we knew what we were doing, it wouldn't be called research, would it?
> -- Albert Einstein
> --
> Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm
> ___
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> group/NEDRA)
>
>


-- 
Put this question to yourself: should I use everyone else to attain
happiness, or should I help others gain happiness?
*Dalai Lama *

Tell me what it is you plan to do
With your one wild and precious life?
Mary Oliver, "The summer day."

To invent, you need a good imagination and a pile of junk.
Thomas A. 
Edison

A public-opinion poll is no substitute for thought.
*Warren Buffet*

Michael E. Ross
(919) 550-2430 Land
(919) 576-0824  Google Phone
(919) 631-1451 Cell
(919) 513-0418 Desk

michael.e.r...@gmail.com

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Re: [EVDL] Recommendations for push mower motor?


Michael Ross wrote:

Any idea if a 24V 1200W mower is a "high" current application?  I am not
sure if I know what "high" and "low" mean in this context.


It's considered a "high" current application. You will probably size 
your batteries so they get discharged in under an hour.



Is this where Li cells shine?  Long life and better peak current
capability?  (I am incapable of asking rhetorical questions about this
stuff- I simply don't know - I promise I am not trolling)


*Every* type of battery has versions that excel in high discharge rate 
applications, and different ones that excel in low discharge rate 
applications.


With lead-acid, use AGMs for high rate, and gels for low rate. Floodeds 
are made in versions for either purpose.


With lithiums, you have so many variations make/model/chemistry that you 
have to closely read the "fine print" to see what they are best at. The 
marketing would have you believe every cell is good for everything!

--
If we knew what we were doing, it wouldn't be called research, would it?
-- Albert Einstein
--
Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm
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Re: [EVDL] Recommendations for push mower motor?

Michael Ross wrote:

my power supply allows me to tell it a peak current and peak voltage...
It sounds like I can safely set the voltage to 28.8V and 4 amps, and
not be concerned if I forget for a few days. Do I have that right?

What is the amphour capacity of your batteries? 28.2v and 4a is OK for
maybe a day, but not for days. At 28.2v, plug the power supply into a
timer and set it to shut off in 16 hours or so.

If you have to leave it on for days, set the voltage for no more than
27.4v (13.7v per 12v battery). That is a relatively safe long-term voltage.

If I am in a hurry, I could wait for 28.8V, then perhaps set it a 30V and
1Amp?

30v and 1 amp max is OK for an hour or two at the most. That will
equalize the batteries.

It all depends on how much babysitting you want to do. Probably the
simplest way is to get one of those 12-hour timers that install in a
light switch box, normally used to control a bathroom fan or outdoor
yard light. For example, an Intermatic FF12HC etc.

http://www.intermatic.com/Products/Timers/InWallTimers/Springwound_Auto-Off_Timers/FFCommercialSeries/FF12HC.aspx

To charge:
- Plug your power supply into the timer.
- Set the timer for 12 hours.
- Set the power supply for 28.8v and its maximum current.
- Wait for it to shut off. The batteries are approximately 100% SOC.

To equalize:
- Charge as above. Then...
- Set the timer for 1 hour.
- Set the power supply for 30v and a maximum current of 2% of the
battery's amphour rating (i.e. 0.4 amps for 20 amphour batteries).
- Wait for it to shut off.

I could rig up a JLD 612 temperature controller to be a minder and shut off
the charge at 100F or so.

When a sealed battery gasses, it heats up and pressurizes the case. If
it charges too long, or at too high a current, it blows the vents open,
and loses water. That's bad for life.

The heat also shortens the battery's life. As temperature rises, the
battery voltage falls. This makes it draw more current, which causes
more heating... This is called "thermal runaway", and leads to
destroying the battery. A good charger has temperature compensation to
detect the temperature rise, and turn down the voltage or shuts off to
prevent this.

I could also mange it for temperature and use a plain old 10A 12V charger
with the cell paralleled. Does this idea have merit/

If that "plain old 12v charger" is any good. Many of them are nothing
but a transformer and rectifier in a box. No voltage, current, or time
control at all.

--
If we knew what we were doing, it wouldn't be called research, would it?
-- Albert Einstein
--
Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm
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Re: [EVDL] Recommendations for push mower motor?

Any idea if a 24V 1200W mower is a "high" current application?  I am not
sure if I know what "high" and "low" mean in this context.

Is this where Li cells shine?  Long life and better peak current
capability?  (I am incapable of asking rhetorical questions about this
stuff- I simply don't know - I promise I am not trolling)

Snip


-- 
Put this question to yourself: should I use everyone else to attain
happiness, or should I help others gain happiness?
*Dalai Lama *

Tell me what it is you plan to do
With your one wild and precious life?
Mary Oliver, "The summer day."

To invent, you need a good imagination and a pile of junk.
Thomas A. 
Edison

A public-opinion poll is no substitute for thought.
*Warren Buffet*

Michael E. Ross
(919) 550-2430 Land
(919) 576-0824  Google Phone
(919) 631-1451 Cell
(919) 513-0418 Desk

michael.e.r...@gmail.com

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Re: [EVDL] Recommendations for push mower motor?


Michael Ross wrote:

Are there non-rape and pillage suppliers for the higher quality gels and
AGM?


Well, I'm cheap. I generally buy my batteries as far away from retail as 
I can get. :-)


Sometimes it's a negotiated price for a quantity purchase. Battery 
dealers have a *large* margin, and so can cut you a good discount if you 
ask (pressure) them.


Sometimes I get "pulls" from a hospital or airport. They use AGMs in 
various battery backup systems, and blindly replace them every few years 
whether they need it or not. If they are no-name junk, they are *bad* in 
3 years. If they are a premium brand, they are likely to still be good.


I also buy them surplus, or sometimes even on eBay. Be sure you can go 
to personally inspect and test them first! People are only too happy to 
sell junk batteries to strangers on the web!



I see higher cycle counts for gels declared in some places...is that true?
  Or is there more to the story - like really hard to charge and discharge
gels so they actually produce that many charge cycles?  (1000 I read.)


Gels are capable of long life; but only the very best premium brands 
will in fact deliver it. Deka Dominators and Gates Cyclons are two that 
I know will last. Deka is really East Penn Mfg. Co, and Gates is now 
Enersys.


It is *easy* to murder a gel cell with excessive charging or 
discharging! They do not like high currents or high voltages. Put a gel 
cell on a standard lead-acid charger, and you are almost certain to ruin it.


--
If we knew what we were doing, it wouldn't be called research, would it?
-- Albert Einstein
--
Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm
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Re: [EVDL] Recommendations for push mower motor?


EVDL Administrator wrote:

simple cycle-dropping charge controller ...

On further thought, somthing occurs to me - I don't think this circuit will
work properly with a filtered DC input (as from a bench supply).  Maybe a
real EE (I'm just a hacker) will weigh in.


Yeah, that's an AC-only circuit. Not a very effective one, either. It 
has a diode *and* a triac in series (2.5v drop out of 12v), and uses 
only uses half-wave rectification. You only get about half the charging 
current that a given transformer could have provided with a full-wave 
rectifier.


It's basically a cost reduced version of the 1970's CitiCar charger. Use 
an SCR in place of the triac, and put back the missing diode to make it 
full-wave, and it would perform much better.


--
If we knew what we were doing, it wouldn't be called research, would it?
-- Albert Einstein
--
Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm
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Re: [EVDL] Recommendations for push mower motor?

Back to charging, and trying to take good care of the celles - in regard to
the 24V pack on my newish mower...my power supply allows me to tell it a
peak current and peak voltage.  It will hold the peak voltage and current
until it reaches the voltage setpoint, then the current drops - to mere
milliamps if I am patient..

It sounds like I can safely set the voltage to 28.8V and 4 amps, and not be
concerned if I forget for a few days.  Do I have that right?

If I am in a hurry, I could wait for 28.8V, then perhaps set it a 30V and
1Amp?

I could rig up a JLD 612 temperature controller to be a minder and shut off
the charge at 100F or so.
JLD 612 has a PID finction so I could turn it on and off to maintain a
temperature setpoint...not sure where exactl toe put the thermocouple or
RTD to sense the temperature though.  Maybe be stick in between a couple of
the batteries.  Does that make any sense.

I am interested in a a walk away not worrying set up (with the stuff I have
on hand.

I could also mange it for temperature and use a plain old 10A 12V charger
with the cell paralleled.  Does this idea have merit/

Thanks,

Mike


-- 
Put this question to yourself: should I use everyone else to attain
happiness, or should I help others gain happiness?
*Dalai Lama *

Tell me what it is you plan to do
With your one wild and precious life?
Mary Oliver, "The summer day."

To invent, you need a good imagination and a pile of junk.
Thomas A. 
Edison

A public-opinion poll is no substitute for thought.
*Warren Buffet*

Michael E. Ross
(919) 550-2430 Land
(919) 576-0824  Google Phone
(919) 631-1451 Cell
(919) 513-0418 Desk

michael.e.r...@gmail.com

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Re: [EVDL] Recommendations for push mower motor?

Thank you all so much, please don't stop commenting.

Are there non-rape and pillage suppliers for the higher quality gels and
AGM?

I see higher cycle counts for gels declared in some places...is that true?
 Or is there more to the story - like really hard to charge and discharge
gels so they actually produce that many charge cycles?  (1000 I read.)


On Tue, Apr 29, 2014 at 1:11 PM, EVDL Administrator  wrote:

> On 29 Apr 2014 at 12:06, Lee Hart wrote:
>
> > I have Enersys, Hawker, and Concorde AGMs that are now over 10 years old
> > and still delivering at least half of their original capacity. I also
> have
> > Gates, and Deka gels just as old that are still usable.
>
> I just recently retired the last of a batch of Hawker Genesis AGMs that
> dated from about 1997.  They were (well-) used when I got them.
>
> Of 24 equally old Deka Dominator gels, I'm still using 16 (and a couple
> others sit around).  Most have 60-90% of their rated capacity.
>
> One of the things I like about these batteries is how low their self
> discharge is.  They need only very infrequent charging when in storage.
>
> David Roden - Akron, Ohio, USA
> EVDL Administrator
>
> = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
> EVDL Information: http://www.evdl.org/help/
> = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
> Note: mail sent to "evpost" and "etpost" addresses will not
> reach me.  To send a private message, please obtain my
> email address from the webpage http://www.evdl.org/help/ .
> = = = = = = = = = = = = = = = = = = = = = = = = = = = = =
>
>
> ___
> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
> http://lists.evdl.org/listinfo.cgi/ev-evdl.org
> For EV drag racing discussion, please use NEDRA (
> http://groups.yahoo.com/group/NEDRA)
>
>


-- 
Put this question to yourself: should I use everyone else to attain
happiness, or should I help others gain happiness?
*Dalai Lama *

Tell me what it is you plan to do
With your one wild and precious life?
Mary Oliver, "The summer day."

To invent, you need a good imagination and a pile of junk.
Thomas A. 
Edison

A public-opinion poll is no substitute for thought.
*Warren Buffet*

Michael E. Ross
(919) 550-2430 Land
(919) 576-0824  Google Phone
(919) 631-1451 Cell
(919) 513-0418 Desk

michael.e.r...@gmail.com

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Re: [EVDL] Recommendations for push mower motor?

On 29 Apr 2014 at 12:06, Lee Hart wrote:

> I have Enersys, Hawker, and Concorde AGMs that are now over 10 years old
> and still delivering at least half of their original capacity. I also have
> Gates, and Deka gels just as old that are still usable.

I just recently retired the last of a batch of Hawker Genesis AGMs that 
dated from about 1997.  They were (well-) used when I got them.  

Of 24 equally old Deka Dominator gels, I'm still using 16 (and a couple 
others sit around).  Most have 60-90% of their rated capacity. 

One of the things I like about these batteries is how low their self 
discharge is.  They need only very infrequent charging when in storage.

David Roden - Akron, Ohio, USA
EVDL Administrator

= = = = = = = = = = = = = = = = = = = = = = = = = = = = =
EVDL Information: http://www.evdl.org/help/
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = 
Note: mail sent to "evpost" and "etpost" addresses will not 
reach me.  To send a private message, please obtain my 
email address from the webpage http://www.evdl.org/help/ .
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Re: [EVDL] Recommendations for push mower motor?


Michael Ross wrote:

I see AGM BP17-12 at amazon prime for $42.  Hard to think of putting in Li
for that cost.

Presumably, all AGM are not created equal - how does one tell good from bad?


Price, and weight are the best indicator. The heavier the battery, the 
more lead in it. The more lead, the better the performance.


If I use cheap AGMs with a product's supplied charger, I only get 1-2 
years out of them. With a good charger, I still only get 2-3 years out 
of them.


But I have Enersys, Hawker, and Concorde AGMs that are now over 10 years 
old and still delivering at least half of their original capacity. I 
also have Gates, and Deka gels just as old that are still usable.


Everything depends on a) the initial quality, b) never abusing them, and 
c) luck. :-)


--
If we knew what we were doing, it wouldn't be called research, would it?
-- Albert Einstein
--
Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm
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Re: [EVDL] Recommendations for push mower motor?

On 29 Apr 2014 at 12:48, EVDL Administrator wrote:

> simple cycle-dropping charge controller ...

On further thought, somthing occurs to me - I don't think this circuit will 
work properly with a filtered DC input (as from a bench supply).  Maybe a 
real EE (I'm just a hacker) will weigh in.

David Roden - Akron, Ohio, USA
EVDL Administrator

= = = = = = = = = = = = = = = = = = = = = = = = = = = = =
EVDL Information: http://www.evdl.org/help/
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = 
Note: mail sent to "evpost" and "etpost" addresses will not 
reach me.  To send a private message, please obtain my 
email address from the webpage http://www.evdl.org/help/ .
= = = = = = = = = = = = = = = = = = = = = = = = = = = = =


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Re: [EVDL] Recommendations for push mower motor?


Michael Ross wrote:

I have an Amrel programmable power supply 4A, 60V.  Very handy for Li-ion.
I am a lead acid dunce. Can I imitate a smart charger with the Amrel
power supply?


Yes, if you supply the "smarts" (i.e. manually control it).


Are there different protocols for conventional, AGM and Gel?  I assume so.


Yes. all lead-acids are similar, but there are minor differences between 
flooded, AGM, and gel.


You can find lots of information (way too much, in fact) on charging 
them online, in books, and from clueless old mechanic's gossip. 
Lead-acids have been around for so long that there are a million 
opinions on how to charge them!


But here are the basics. The exact voltages will depend on the type of 
battery, its temperature, age, and condition. For best results, see the 
manufacturer's recommendations. (Which by the way, tend to err on the 
high side, and only apply when the battery is brand new).


1. Bulk:

Charge them at as high a current as you like until the voltage reaches 
the gassing point; about 2.25-2.3v per cell. The battery doesn't care; 
the charger is what usually limits the current in this step. At this 
point, the battery is about 80% charged.


2. Absorption:

Now limit the voltage to around 2.4v/cell (14.4v for a 12v battery). The 
current will fall as the battery continues to charge. The battery is 
100% charged when the current stops falling, or falls under 2% of the 
battery's amphour capacity (like 1 amp for a 50 amphour battery).


3. Finish, or Equalization (optional):

Continue charging at very low current, like 1% to 2% of the battery's 
amphour capacity, and let the voltage keep rising. End when:


 - the voltage reaches 2.5v/cell (15v for a 12v battery),
 - or the voltage stops rising,
 - or 1 to 2 hours has elapsed.

This step isn't necessary on every charge cycle. Do it as needed. Wait 
at least 8 hours after charging, then measure the voltages between 
batteries (or cells, if you can get at them). Do step 3 if the highest 
and lowest differ by more than 1%.


--
If we knew what we were doing, it wouldn't be called research, would it?
-- Albert Einstein
--
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Re: [EVDL] Recommendations for push mower motor?

On 29 Apr 2014 at 10:53, Michael Ross wrote:

> I am a lead acid dunce.  Can I imitate a smart charger with the Amrel
>  power supply?
> 
> Are there different protocols for conventional, AGM and Gel?  I assume so.

Here is a good introduction to lead battery charging:

http://www.evdl.org/pages/hartcharge.html

If you set your bench supply to the battery manufacturer's recommended 
charging voltage (typically 2.4 to 2.5 volts per cell for flooded, 2.35 to 
2.5 for AGM, and 2.35 for gel), it will be a taper charger and will safely 
charge the battery.  It can take a long time to reach full charge, though.

To charge faster, do as Lee recommends in that document, or build a charge 
controller that does it automatically.  

Coincidentally, I was just suggesting to someone on the Elec-Trak list that 
he try building a simple cycle-dropping charge controller similar to this 
one:

http://www.aaroncake.net/circuits/charger2.asp?showcomments=all

I've built a number of chargers with these circuits over the years.  They 
work, though they're not very sophisticated.  

Many car battery chargers use a similar circuit.  This design was also used 
for the charger in the early-80s Comuta-Car (not that that's much of an 
endorsement).  I think the original Rudman Regulators of 20-some years ago 
were similar to this circuit too, but I may be wrong about that.

Obviously you adjust the components to your situation (charging current and 
battery voltage).  Change C1, R1, R3, and maybe D3  for different voltages, 
and change the triac for higher currents.

Other than just regulating the charger and doing straight taper charging, 
this is about the most minimal charge controller I know of.

David Roden - Akron, Ohio, USA
EVDL Administrator

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Re: [EVDL] Recommendations for push mower motor?

I see AGM BP17-12 at amazon prime for $42.  Hard to think of putting in Li
for that cost.

Presumably, all AGM are not created equal - how does one tell good from bad?


On Tue, Apr 29, 2014 at 11:10 AM, Martin WINLOW  wrote:

> Speed is comparable, then.  I had a quick look on ebay - dual 18V set ups
> (might even use the same battery packs as your existing cordless drill) but
> one DeWalt (300 model) is 36V using standard 36V pack with a 900W motor -
> is this enough?  I'd be easy enough to mount and just re position the
> switch - every thing is there bar mounting the cutter.  Even that might be
> pretty simple... MW
>
>
> On 29 Apr 2014, at 15:58, Michael Ross wrote:
>
> > Answers here:
> > http://bit.ly/1tZLfMD
> >
> > On Tue, Apr 29, 2014 at 10:49 AM, Martin WINLOW  wrote:
> >
> >> *What sort of RPM does a mower use?  *SNIP
> >
> >
> > Up to 3600RPM for ICE depending on load.
> > plug in electric probably the same.
> >
> > Part of what you care about is tip speed.  If the blade is short it need
> > more rpm.
> >
>
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-- 
Put this question to yourself: should I use everyone else to attain
happiness, or should I help others gain happiness?
*Dalai Lama *

Tell me what it is you plan to do
With your one wild and precious life?
Mary Oliver, "The summer day."

To invent, you need a good imagination and a pile of junk.
Thomas A. 
Edison

A public-opinion poll is no substitute for thought.
*Warren Buffet*

Michael E. Ross
(919) 550-2430 Land
(919) 576-0824  Google Phone
(919) 631-1451 Cell
(919) 513-0418 Desk

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Re: [EVDL] Recommendations for push mower motor?

2014-04-29 Thread Martin WINLOW

Speed is comparable, then.  I had a quick look on ebay - dual 18V set ups 
(might even use the same battery packs as your existing cordless drill) but one 
DeWalt (300 model) is 36V using standard 36V pack with a 900W motor - is this 
enough?  I'd be easy enough to mount and just re position the switch - every 
thing is there bar mounting the cutter.  Even that might be pretty simple... MW

On 29 Apr 2014, at 15:58, Michael Ross wrote:

> Answers here:
> http://bit.ly/1tZLfMD
> 
> On Tue, Apr 29, 2014 at 10:49 AM, Martin WINLOW  wrote:
> 
>> *What sort of RPM does a mower use?  *SNIP
> 
> 
> Up to 3600RPM for ICE depending on load.
> plug in electric probably the same.
> 
> Part of what you care about is tip speed.  If the blade is short it need
> more rpm.
> 

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Re: [EVDL] Recommendations for push mower motor?

Answers here:
http://bit.ly/1tZLfMD

On Tue, Apr 29, 2014 at 10:49 AM, Martin WINLOW  wrote:

> *What sort of RPM does a mower use?  *SNIP


Up to 3600RPM for ICE depending on load.
plug in electric probably the same.

Part of what you care about is tip speed.  If the blade is short it need
more rpm.

-- 
Put this question to yourself: should I use everyone else to attain
happiness, or should I help others gain happiness?
*Dalai Lama *

Tell me what it is you plan to do
With your one wild and precious life?
Mary Oliver, "The summer day."

To invent, you need a good imagination and a pile of junk.
Thomas A. 
Edison

A public-opinion poll is no substitute for thought.
*Warren Buffet*

Michael E. Ross
(919) 550-2430 Land
(919) 576-0824  Google Phone
(919) 631-1451 Cell
(919) 513-0418 Desk

michael.e.r...@gmail.com

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Re: [EVDL] Recommendations for push mower motor?

I have an Amrel programmable power supply 4A, 60V.  Very handy for Li-ion.

I am a lead acid dunce.  Can I imitate a smart charger with the Amrel
 power supply?

Are there different protocols for conventional, AGM and Gel?  I assume so.


On Tue, Apr 29, 2014 at 9:40 AM, Lee Hart  wrote:

> Craigslist brought me a B&D CMM1200 which seems to be quite a hoss at
>>> 1200W. 24V. Bagger/mulcher, 1.5A charger.
>>>
>>
> EVDL Administrator wrote:
>
>> Good find!  Note that 1200 watts is>peak< - ask those little gel batteries
>> to deliver 50 amps for more than a few seconds and see how far they get
>> you!
>>
>> Unless B&D have made some drastic charger improvements in recent years
>> (which I doubt), you can significantly improve your battery life with
>> these
>> mowers by chucking out the crappy wall wart charger they come with, and
>> replacing it with a good smart charger.
>>
>
> I agree. I have a 36v Black and Decker mower, bought from a damaged
> freight outlet (the self-propelled feature is broken, and one wheel was
> bent).
>
> The charger I got with it is first-class grade-A (for awful) junk. The
> best they could get for a dollar. Don't use it unless you only want your
> batteries to last a year or or two.
>
> Mine came with AGMs, not gels. But they are really cheap off-brand ones.
>
>
> --
> If we knew what we were doing, it wouldn't be called research, would it?
> -- Albert Einstein
> --
> Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm
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> group/NEDRA)
>
>


-- 
Put this question to yourself: should I use everyone else to attain
happiness, or should I help others gain happiness?
*Dalai Lama *

Tell me what it is you plan to do
With your one wild and precious life?
Mary Oliver, "The summer day."

To invent, you need a good imagination and a pile of junk.
Thomas A. 
Edison

A public-opinion poll is no substitute for thought.
*Warren Buffet*

Michael E. Ross
(919) 550-2430 Land
(919) 576-0824  Google Phone
(919) 631-1451 Cell
(919) 513-0418 Desk

michael.e.r...@gmail.com

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Re: [EVDL] Recommendations for push mower motor?

2014-04-29 Thread Martin WINLOW

What sort of RPM does a mower use?  The corded electric Mountfield we use does 
not appear to have a gearbox.  So, would a 36/48V cordless circular saw be a 
possible starting point (if there is such a beast!)?  It'd certainly make 
battery swapping very easy! MW


On 28 Apr 2014, at 17:58, Michael Ross wrote:

> I have an old simple ICE push mower, that might be worth converting.
> 
> Can anyone recommend the sort of motor I should look for?
> 
> Re-purposing a motor would be nice.
> 
> I would use LFP batteries.
> 
> What about the shock of the blade hitting something nearly immobile? That
> is a lot of shock that small engines are able to handle - special
> consideration in the regard with electric motors?
> 
> Mounting the blade seem non-trivial?  Hints?
> 
> Thanks!
> 
> I just saw a Li ion powered mower on line for $500.  supposed to run for 45
> minutes and charge back in 30.  That sounds like a practical target.  48V
> pack.  Weighs 62lb.
> 
> Any thought on this side of the equation?  36V?  60V?  Capacity needed to
> go 45 minutes?
> 
> -- 
> Don't believe everything you read on the Internet - Abraham Lincoln
> 
> A public-opinion poll is no substitute for thought.
> *Warren Buffet*
> 
> Michael E. Ross
> (919) 550-2430 Land
> (919) 576-0824  Google Phone
> (919) 631-1451 Cell
> (919) 513-0418 Desk
> 
> michael.e.r...@gmail.com
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Re: [EVDL] Recommendations for push mower motor?


Craigslist brought me a B&D CMM1200 which seems to be quite a hoss at
1200W. 24V. Bagger/mulcher, 1.5A charger.


EVDL Administrator wrote:

Good find!  Note that 1200 watts is>peak< - ask those little gel batteries
to deliver 50 amps for more than a few seconds and see how far they get you!

Unless B&D have made some drastic charger improvements in recent years
(which I doubt), you can significantly improve your battery life with these
mowers by chucking out the crappy wall wart charger they come with, and
replacing it with a good smart charger.


I agree. I have a 36v Black and Decker mower, bought from a damaged 
freight outlet (the self-propelled feature is broken, and one wheel was 
bent).


The charger I got with it is first-class grade-A (for awful) junk. The 
best they could get for a dollar. Don't use it unless you only want your 
batteries to last a year or or two.


Mine came with AGMs, not gels. But they are really cheap off-brand ones.

--
If we knew what we were doing, it wouldn't be called research, would it?
-- Albert Einstein
--
Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm
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Re: [EVDL] Recommendations for push mower motor?

On 28 Apr 2014 at 19:17, Michael Ross wrote:

> Craigslist brought me a B&D CMM1200 which seems to be quite a hoss at
> 1200W.   24V.   Bagger/mulcher,  1.5A charger. 

Good find!  Note that 1200 watts is >peak< - ask those little gel batteries 
to deliver 50 amps for more than a few seconds and see how far they get you!

Unless B&D have made some drastic charger improvements in recent years 
(which I doubt), you can significantly improve your battery life with these 
mowers by chucking out the crappy wall wart charger they come with, and 
replacing it with a good smart charger.

David Roden - Akron, Ohio, USA
EVDL Administrator

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Note: mail sent to "evpost" and "etpost" addresses will not 
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Re: [EVDL] Recommendations for push mower motor?

2014-04-28 Thread Mark Hastings

I have a cordless B&D that i changed out to use 24v 20ah thundersky batts a
few seasons ago and shared the battery for a while on my recumbent for
assist.  It certainly won't do my new 2+ acres but was cheap with dead
batteries off of craigslist and the lighter batteries made it tolerable to
push in the hundred degree heat. All it took was remove the old battery,
connect the new one and I lazily just popped it out to take to the workshop for
charging instead of making it permanent since it was intended to be a dual
use battery.

On Monday, April 28, 2014, Michael Ross  wrote:

> I have another battery from these people that seems just fine (after taking
> it apart to see inside)
>
>
> http://www.aliexpress.com/store/product/24V-40AH-LiFePO4-Battery-Pack-Electric-Bicycle-electric-Scooter-bicycle-E-Bike-Lithium-Ion-Long-life/328001_771068114.html
>
> This one is 24V 40Ah LFP and weighs 9kg.  $500 including shipping BMS and
> charger. 3 to 7 day delivery and the met that. These that 18650 cells with
> welded straps for conducting the juice.
>
> I think I will try to get a used 24V B&D instead of reworking my old bottom
> of the line MTD.
>
> I think my wife would love to have an electric mower.  She hates asking me
> to start them for her.  It would be nice not having all the oil checking
> and filling,   And as the current mower works - the rod knocking and
> smoking.  We have an acre of mostly flat yard - 40Ah would go a long ways
> and the charge time is about 2 hours.
>
>
> On Mon, Apr 28, 2014 at 3:25 PM, Peter Eckhoff  wrote:
>
> > Hello Mike,
> >
> > I'll second what Cal is saying below.  To get the nut off, you have to
> > place a wrench on the nut and "impact" it until the nut loosens.  I would
> > **not** use a compressed air impactor tool.  I use my fist.  Be careful
> > because everything is free wheeling.  If you leave your knuckles in the
> > path of the blade, your knuckles are going to get whacked.  There is no
> > other place to place another wrench unless you weld a nut to the top of
> the
> > motor shaft.
> >
> > Like Cal, I keep a set of several "small plastic blade insulators" on
> hand
> > which is how they are described in the User's Manual.  The word
> "insulator"
> > may seem like a misnomer but it is to "insulate" the shock of hitting a
> > rock from damaging the armature.
> >
> > I converted a corded B&D to cordless.  It uses 9 - 5 amphr 12 volt LA
> AGMs
> > to power the mower.  It is enough to do a 7K square foot lawn.  What used
> > to take me 1.5 hours to do when corded, now takes about 45 minutes.
> >
> > I use a 1.3 amphr AGM for the tripping a small contactor.  This battery
> > goes down faster than the pack.  I would use about a 2 amphr battery for
> > each hour the contactors are tripped.  That should give you plenty of
> > cushion.
> >
> > I wrote a two part article for the Electric Auto Association's Current
> > Events magazine.  I have the submittals in PDF format. The B&D motors are
> > DC universal motors that operate at 120 volts.  The corded version has a
> > full rectifier bridge on a little heat sink.  It was mainly a rewiring
> job
> > to bypass the rectifier.
> >
> > I think the AGMs are the wrong type of battery for this project.
> Normally,
> > when not cutting the lawn, the motor consumes about 4 amps.  When cutting
> > thick grass, the motor consumes about 8 amps. It can spike to 10 amps in
> > real thick grass or when the mower clogs up in thick grass.
> >
> > I have been contemplating upgrading this mower to Lithium.  A set of 40 -
> > 3.2 volt 10 amphr would be about right for an hour's worth of cutting and
> > still have some reserve.  I saw an ad for Shorai 12Volt 12 Amphr
> batteries
> >  for $117 each and they weigh about 1.7 pounds.  My 5.0 amphr batteries
> > weigh 3.5 pounds each for an added weight (starter + pack support +
> > contactor) of 35 pounds onto a mower that weighs 47 pounds for a total of
> > around 82 pounds.  This is about the weight of an ICE push mower.  Twelve
> > Shorai batteries would be around 20 pounds.  The mower would be lighter
> and
> > so would your wallet of $1400 plus shipping.
> >
> > I have thought about purchasing 4 - 100 amphr CALB batteries and then use
> > a converter to step up the voltage to 120 volts.  At an efficiency of
> 85%,
> > the amphrs to the motor would be about 8.5.  I am not sure if a converter
> > could handle that much amperage.  I was going to do some more homework
> > before asking the experts here. Four CALB batteries would be about 600
> > dollars and a converter would run in the lower several hundreds.  The
> > savings would be substantial but I am not sure if the electronics would
> > handle the load.
> >
> > The other thought would be to run the 4 CALBs into an inverter and leave
> > the rectifier bridge intact.  The inefficiency of the inverter plus the
> > inefficiency of the rectifier bridge would likely sap the pack of a lot
> of
> > useful energy.  I think this would be a nonstarter.
> >

Re: [EVDL] Recommendations for push mower motor?

2014-04-28 Thread David Nelson

KTA drop ships them from another supplier in the US. I've always had
good luck with KTA so that is why I ordered from them. It sounded like
they periodically get orders in and ship from that. I don't remember
how long it took mine to show up but it was less than 3 weeks. They
are a really nice size. Basically they are like small versions of the
TS cells I put in my Gizmo. The lids on the packs I received actually
covered the exposed terminals better than the ones in the picture on
KTAs website. If you capacity test to the specs that the manufacturer
gives they deliver 20Ah but if you limit your charge to a more
reasonable high of 3.6V at 1A or 3.4V at nearly 0A for your cutoff and
stop discharge at 2.5V with a 0.5C load you will realize close to
19Ah. I'm not at home right now so I can't check my data.

On Mon, Apr 28, 2014 at 8:13 PM, Michael Ross  wrote:
> Thanks, David, that sounds like a good fit.  Sounds like the 40AH I was
> looking at are way overkill.
>
> They ship in 2 to 3 weeks - sounds like they are not stocking, just
> brokering for a Chinese manufacturer.
>
> This is all speculation, because I may like the Pb cells in it just fine.
>  I wonder how much they would  cost.  I am not familiar with buying lead
> batteries, except from the auto parts store.
>
>
>
> On Mon, Apr 28, 2014 at 10:00 PM, David Nelson  wrote:
>
>> I picked up a B&D 24V push mower for free. It needed batteries and a
>> charger. I removed the charging circuit & batteries and replaced the
>> batteries with two sets of GBS 20Ah
>> (
>> http://www.kta-ev.com/Battery_4_GBS_3_2V_20AH_cells_p/bat-gbs-lfmp20ahx4.htm
>> )
>> which are an almost exact size replacement for the lead acid
>> batteries. I installed a self powered digital volt meter in place of
>> the old analog meter and carefully bottom balanced the pack. I know
>> when to stop mowing when the voltage reads 20V when not cutting grass.
>> They bounce back to just over 3V per cell. I don't have a charging
>> plug yet so I still have to remove the cover and charge the batteries
>> with my bench power supply. Charging to 3.4V per cell average means I
>> don't have to worry about overcharging the cells. Yes, I checked. It
>> seems like it just runs for ever. It could mulch mow the yard of a
>> 1200 ft^2 ranch style house on a 6000 ft^2 lot (I'm not sure of the
>> lawn area) and still have energy left.
>>
>> On Mon, Apr 28, 2014 at 9:58 AM, Michael Ross 
>> wrote:
>> > I have an old simple ICE push mower, that might be worth converting.
>> >
>> > Can anyone recommend the sort of motor I should look for?
>> >
>> > Re-purposing a motor would be nice.
>> >
>> > I would use LFP batteries.
>> >
>> > What about the shock of the blade hitting something nearly immobile? That
>> > is a lot of shock that small engines are able to handle - special
>> > consideration in the regard with electric motors?
>> >
>> > Mounting the blade seem non-trivial?  Hints?
>> >
>> > Thanks!
>> >
>> > I just saw a Li ion powered mower on line for $500.  supposed to run for
>> 45
>> > minutes and charge back in 30.  That sounds like a practical target.  48V
>> > pack.  Weighs 62lb.
>> >
>> > Any thought on this side of the equation?  36V?  60V?  Capacity needed to
>> > go 45 minutes?
>> >
>> > --
>> > Don't believe everything you read on the Internet - Abraham Lincoln
>> >
>> > A public-opinion poll is no substitute for thought.
>> > *Warren Buffet*
>> >
>> > Michael E. Ross
>> > (919) 550-2430 Land
>> > (919) 576-0824  Google
>> Phone
>> > (919) 631-1451 Cell
>> > (919) 513-0418 Desk
>> >
>> > michael.e.r...@gmail.com
>> > 
>> > -- next part --
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>> >
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>> > For EV drag racing discussion, please use NEDRA (
>> http://groups.yahoo.com/group/NEDRA)
>> >
>>
>>
>>
>> --
>> David D. Nelson
>> http://evalbum.com/1328
>> http://www.levforum.com
>> ___
>> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
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>> http://groups.yahoo.com/group/NEDRA)
>>
>>
>
>
> --
> Put this question to yourself: should I use everyone else to attain
> happiness, or should I help others gain happiness?
> *Dalai Lama *
>
> Tell me what it is you plan to do
> With your one wild and precious life?
> Mary Oliver, "The summer day."
>
> To invent, you need a good imagination and a pile of junk.
> Thomas A. 
> Edison
>
> A public-opinion poll is no substitute for thought.
> *Warren Buffet*
>
> Michael E. Ross
> (919) 550-2430 Land
> (919) 576-0824

Re: [EVDL] Recommendations for push mower motor?

Thanks, David, that sounds like a good fit.  Sounds like the 40AH I was
looking at are way overkill.

They ship in 2 to 3 weeks - sounds like they are not stocking, just
brokering for a Chinese manufacturer.

This is all speculation, because I may like the Pb cells in it just fine.
 I wonder how much they would  cost.  I am not familiar with buying lead
batteries, except from the auto parts store.



On Mon, Apr 28, 2014 at 10:00 PM, David Nelson  wrote:

> I picked up a B&D 24V push mower for free. It needed batteries and a
> charger. I removed the charging circuit & batteries and replaced the
> batteries with two sets of GBS 20Ah
> (
> http://www.kta-ev.com/Battery_4_GBS_3_2V_20AH_cells_p/bat-gbs-lfmp20ahx4.htm
> )
> which are an almost exact size replacement for the lead acid
> batteries. I installed a self powered digital volt meter in place of
> the old analog meter and carefully bottom balanced the pack. I know
> when to stop mowing when the voltage reads 20V when not cutting grass.
> They bounce back to just over 3V per cell. I don't have a charging
> plug yet so I still have to remove the cover and charge the batteries
> with my bench power supply. Charging to 3.4V per cell average means I
> don't have to worry about overcharging the cells. Yes, I checked. It
> seems like it just runs for ever. It could mulch mow the yard of a
> 1200 ft^2 ranch style house on a 6000 ft^2 lot (I'm not sure of the
> lawn area) and still have energy left.
>
> On Mon, Apr 28, 2014 at 9:58 AM, Michael Ross 
> wrote:
> > I have an old simple ICE push mower, that might be worth converting.
> >
> > Can anyone recommend the sort of motor I should look for?
> >
> > Re-purposing a motor would be nice.
> >
> > I would use LFP batteries.
> >
> > What about the shock of the blade hitting something nearly immobile? That
> > is a lot of shock that small engines are able to handle - special
> > consideration in the regard with electric motors?
> >
> > Mounting the blade seem non-trivial?  Hints?
> >
> > Thanks!
> >
> > I just saw a Li ion powered mower on line for $500.  supposed to run for
> 45
> > minutes and charge back in 30.  That sounds like a practical target.  48V
> > pack.  Weighs 62lb.
> >
> > Any thought on this side of the equation?  36V?  60V?  Capacity needed to
> > go 45 minutes?
> >
> > --
> > Don't believe everything you read on the Internet - Abraham Lincoln
> >
> > A public-opinion poll is no substitute for thought.
> > *Warren Buffet*
> >
> > Michael E. Ross
> > (919) 550-2430 Land
> > (919) 576-0824  Google
> Phone
> > (919) 631-1451 Cell
> > (919) 513-0418 Desk
> >
> > michael.e.r...@gmail.com
> > 
> > -- next part --
> > An HTML attachment was scrubbed...
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> http://lists.evdl.org/private.cgi/ev-evdl.org/attachments/20140428/7e307136/attachment.htm
> >
> > ___
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> > For EV drag racing discussion, please use NEDRA (
> http://groups.yahoo.com/group/NEDRA)
> >
>
>
>
> --
> David D. Nelson
> http://evalbum.com/1328
> http://www.levforum.com
> ___
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> http://groups.yahoo.com/group/NEDRA)
>
>


-- 
Put this question to yourself: should I use everyone else to attain
happiness, or should I help others gain happiness?
*Dalai Lama *

Tell me what it is you plan to do
With your one wild and precious life?
Mary Oliver, "The summer day."

To invent, you need a good imagination and a pile of junk.
Thomas A. 
Edison

A public-opinion poll is no substitute for thought.
*Warren Buffet*

Michael E. Ross
(919) 550-2430 Land
(919) 576-0824  Google Phone
(919) 631-1451 Cell
(919) 513-0418 Desk

michael.e.r...@gmail.com

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Re: [EVDL] Recommendations for push mower motor?

2014-04-28 Thread David Nelson

I picked up a B&D 24V push mower for free. It needed batteries and a
charger. I removed the charging circuit & batteries and replaced the
batteries with two sets of GBS 20Ah
(http://www.kta-ev.com/Battery_4_GBS_3_2V_20AH_cells_p/bat-gbs-lfmp20ahx4.htm)
which are an almost exact size replacement for the lead acid
batteries. I installed a self powered digital volt meter in place of
the old analog meter and carefully bottom balanced the pack. I know
when to stop mowing when the voltage reads 20V when not cutting grass.
They bounce back to just over 3V per cell. I don't have a charging
plug yet so I still have to remove the cover and charge the batteries
with my bench power supply. Charging to 3.4V per cell average means I
don't have to worry about overcharging the cells. Yes, I checked. It
seems like it just runs for ever. It could mulch mow the yard of a
1200 ft^2 ranch style house on a 6000 ft^2 lot (I'm not sure of the
lawn area) and still have energy left.

On Mon, Apr 28, 2014 at 9:58 AM, Michael Ross  wrote:
> I have an old simple ICE push mower, that might be worth converting.
>
> Can anyone recommend the sort of motor I should look for?
>
> Re-purposing a motor would be nice.
>
> I would use LFP batteries.
>
> What about the shock of the blade hitting something nearly immobile? That
> is a lot of shock that small engines are able to handle - special
> consideration in the regard with electric motors?
>
> Mounting the blade seem non-trivial?  Hints?
>
> Thanks!
>
> I just saw a Li ion powered mower on line for $500.  supposed to run for 45
> minutes and charge back in 30.  That sounds like a practical target.  48V
> pack.  Weighs 62lb.
>
> Any thought on this side of the equation?  36V?  60V?  Capacity needed to
> go 45 minutes?
>
> --
> Don't believe everything you read on the Internet - Abraham Lincoln
>
> A public-opinion poll is no substitute for thought.
> *Warren Buffet*
>
> Michael E. Ross
> (919) 550-2430 Land
> (919) 576-0824  Google Phone
> (919) 631-1451 Cell
> (919) 513-0418 Desk
>
> michael.e.r...@gmail.com
> 
> -- next part --
> An HTML attachment was scrubbed...
> URL: 
> 
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> http://lists.evdl.org/listinfo.cgi/ev-evdl.org
> For EV drag racing discussion, please use NEDRA 
> (http://groups.yahoo.com/group/NEDRA)
>

-- 
David D. Nelson
http://evalbum.com/1328
http://www.levforum.com
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Re: [EVDL] Recommendations for push mower motor?

Hi thank you all for the advice, and so fast.

I took the advice to work with a cordless mower rather than re-purpose an
ICE mower.   Craigslist brought me a B&D CMM1200 which seems to be quite a
hoss at 1200W.   24V.   Bagger/mulcher,  1.5A charger.  The only thing I
could see amiss was a missing knob on the push structure replaced with a
hex nut, and a worn out blade.  The batteries look like two gel Pb cells
shrink wrapper together - not very big by the scale of the diagram.  The
wheel leveling seemed very easy - hope it holds up.  I like the thick
plastic hull - I think that makes a lot of sense - polyethylene can take a
lot of abuse and will bend not break. The owner did not have a very big
yard so he couldn't say much about mowing time.  $145 seemed like a very
fair price.

I will be curious to see where it cuts off and to what voltage it charges.

I guess I will have to find some other thing to convert.


On Mon, Apr 28, 2014 at 6:05 PM, Peter Eckhoff  wrote:

> Thanks Mike for the recommendation.
>
> My blade on my B&D MM675 measures 17.5" even though the specs say 18"
> cutting path.  Most of the lower voltage electrics have a 14" blade.  The
> smaller mower means more passes.  Something to think about.
>
>
> On 4/28/2014 3:45 PM, Michael Ross wrote:
>
>> I have another battery from these people that seems just fine (after
>> taking
>> it apart to see inside)
>>
>> http://www.aliexpress.com/store/product/24V-40AH-
>> LiFePO4-Battery-Pack-Electric-Bicycle-electric-Scooter-
>> bicycle-E-Bike-Lithium-Ion-Long-life/328001_771068114.html
>>
>> This one is 24V 40Ah LFP and weighs 9kg.  $500 including shipping BMS and
>> charger. 3 to 7 day delivery and the met that. These that 18650 cells with
>> welded straps for conducting the juice.
>>
>> I think I will try to get a used 24V B&D instead of reworking my old
>> bottom
>> of the line MTD.
>>
>> I think my wife would love to have an electric mower.  She hates asking me
>> to start them for her.  It would be nice not having all the oil checking
>> and filling,   And as the current mower works - the rod knocking and
>> smoking.  We have an acre of mostly flat yard - 40Ah would go a long ways
>> and the charge time is about 2 hours.
>>
>>
>> On Mon, Apr 28, 2014 at 3:25 PM, Peter Eckhoff 
>> wrote:
>>
>>  Hello Mike,
>>>
>>> I'll second what Cal is saying below.  To get the nut off, you have to
>>> place a wrench on the nut and "impact" it until the nut loosens.  I would
>>> **not** use a compressed air impactor tool.  I use my fist.  Be careful
>>> because everything is free wheeling.  If you leave your knuckles in the
>>> path of the blade, your knuckles are going to get whacked.  There is no
>>> other place to place another wrench unless you weld a nut to the top of
>>> the
>>> motor shaft.
>>>
>>> Like Cal, I keep a set of several "small plastic blade insulators" on
>>> hand
>>> which is how they are described in the User's Manual.  The word
>>> "insulator"
>>> may seem like a misnomer but it is to "insulate" the shock of hitting a
>>> rock from damaging the armature.
>>>
>>> I converted a corded B&D to cordless.  It uses 9 - 5 amphr 12 volt LA
>>> AGMs
>>> to power the mower.  It is enough to do a 7K square foot lawn.  What used
>>> to take me 1.5 hours to do when corded, now takes about 45 minutes.
>>>
>>> I use a 1.3 amphr AGM for the tripping a small contactor.  This battery
>>> goes down faster than the pack.  I would use about a 2 amphr battery for
>>> each hour the contactors are tripped.  That should give you plenty of
>>> cushion.
>>>
>>> I wrote a two part article for the Electric Auto Association's Current
>>> Events magazine.  I have the submittals in PDF format. The B&D motors are
>>> DC universal motors that operate at 120 volts.  The corded version has a
>>> full rectifier bridge on a little heat sink.  It was mainly a rewiring
>>> job
>>> to bypass the rectifier.
>>>
>>> I think the AGMs are the wrong type of battery for this project.
>>> Normally,
>>> when not cutting the lawn, the motor consumes about 4 amps.  When cutting
>>> thick grass, the motor consumes about 8 amps. It can spike to 10 amps in
>>> real thick grass or when the mower clogs up in thick grass.
>>>
>>> I have been contemplating upgrading this mower to Lithium.  A set of 40 -
>>> 3.2 volt 10 amphr would be about right for an hour's worth of cutting and
>>> still have some reserve.  I saw an ad for Shorai 12Volt 12 Amphr
>>> batteries
>>>   for $117 each and they weigh about 1.7 pounds.  My 5.0 amphr batteries
>>> weigh 3.5 pounds each for an added weight (starter + pack support +
>>> contactor) of 35 pounds onto a mower that weighs 47 pounds for a total of
>>> around 82 pounds.  This is about the weight of an ICE push mower.  Twelve
>>> Shorai batteries would be around 20 pounds.  The mower would be lighter
>>> and
>>> so would your wallet of $1400 plus shipping.
>>>
>>> I have thought about purchasing 4 - 100 amphr CALB batteries and then use
>>> a converter to step up

Re: [EVDL] Recommendations for push mower motor?

2014-04-28 Thread Peter Eckhoff


>>http://www.aliexpress.com/store/product/24V-40AH-LiFePO4-Battery-Pack-Electric-Bicycle-electric-Scooter-bicycle-E-Bike-Lithium-Ion-Long-life/328001_771068114.html
 <<
Thanks Mike for the recommendation.

My blade on my B&D MM675 measures 17.5" even though the specs say 18" 
cutting path.  Most of the lower voltage electrics have a 14" blade.  
The smaller mower means more passes.  Something to think about.

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Re: [EVDL] Recommendations for push mower motor?

2014-04-28 Thread Peter Eckhoff

Thanks Mike for the recommendation.

My blade on my B&D MM675 measures 17.5" even though the specs say 18"
cutting path. Most of the lower voltage electrics have a 14" blade.
The smaller mower means more passes. Something to think about.

On 4/28/2014 3:45 PM, Michael Ross wrote:

I have another battery from these people that seems just fine (after taking
it apart to see inside)

http://www.aliexpress.com/store/product/24V-40AH-LiFePO4-Battery-Pack-Electric-Bicycle-electric-Scooter-bicycle-E-Bike-Lithium-Ion-Long-life/328001_771068114.html

This one is 24V 40Ah LFP and weighs 9kg. $500 including shipping BMS and
charger. 3 to 7 day delivery and the met that. These that 18650 cells with
welded straps for conducting the juice.

I think I will try to get a used 24V B&D instead of reworking my old bottom
of the line MTD.

I think my wife would love to have an electric mower. She hates asking me
to start them for her. It would be nice not having all the oil checking
and filling, And as the current mower works - the rod knocking and
smoking. We have an acre of mostly flat yard - 40Ah would go a long ways
and the charge time is about 2 hours.

On Mon, Apr 28, 2014 at 3:25 PM, Peter Eckhoff wrote:

Hello Mike,

I'll second what Cal is saying below. To get the nut off, you have to
place a wrench on the nut and "impact" it until the nut loosens. I would
**not** use a compressed air impactor tool. I use my fist. Be careful
because everything is free wheeling. If you leave your knuckles in the
path of the blade, your knuckles are going to get whacked. There is no
other place to place another wrench unless you weld a nut to the top of the
motor shaft.

Like Cal, I keep a set of several "small plastic blade insulators" on hand
which is how they are described in the User's Manual. The word "insulator"
may seem like a misnomer but it is to "insulate" the shock of hitting a
rock from damaging the armature.

I converted a corded B&D to cordless. It uses 9 - 5 amphr 12 volt LA AGMs
to power the mower. It is enough to do a 7K square foot lawn. What used
to take me 1.5 hours to do when corded, now takes about 45 minutes.

I use a 1.3 amphr AGM for the tripping a small contactor. This battery
goes down faster than the pack. I would use about a 2 amphr battery for
each hour the contactors are tripped. That should give you plenty of
cushion.

I wrote a two part article for the Electric Auto Association's Current
Events magazine. I have the submittals in PDF format. The B&D motors are
DC universal motors that operate at 120 volts. The corded version has a
full rectifier bridge on a little heat sink. It was mainly a rewiring job
to bypass the rectifier.

I think the AGMs are the wrong type of battery for this project. Normally,
when not cutting the lawn, the motor consumes about 4 amps. When cutting
thick grass, the motor consumes about 8 amps. It can spike to 10 amps in
real thick grass or when the mower clogs up in thick grass.

I have been contemplating upgrading this mower to Lithium. A set of 40 -
3.2 volt 10 amphr would be about right for an hour's worth of cutting and
still have some reserve. I saw an ad for Shorai 12Volt 12 Amphr batteries
for $117 each and they weigh about 1.7 pounds. My 5.0 amphr batteries
weigh 3.5 pounds each for an added weight (starter + pack support +
contactor) of 35 pounds onto a mower that weighs 47 pounds for a total of
around 82 pounds. This is about the weight of an ICE push mower. Twelve
Shorai batteries would be around 20 pounds. The mower would be lighter and
so would your wallet of $1400 plus shipping.

I have thought about purchasing 4 - 100 amphr CALB batteries and then use
a converter to step up the voltage to 120 volts. At an efficiency of 85%,
the amphrs to the motor would be about 8.5. I am not sure if a converter
could handle that much amperage. I was going to do some more homework
before asking the experts here. Four CALB batteries would be about 600
dollars and a converter would run in the lower several hundreds. The
savings would be substantial but I am not sure if the electronics would
handle the load.

The other thought would be to run the 4 CALBs into an inverter and leave
the rectifier bridge intact. The inefficiency of the inverter plus the
inefficiency of the rectifier bridge would likely sap the pack of a lot of
useful energy. I think this would be a nonstarter.

I know of someone using a self contained electric mower. You might want
to shoot him an email at theadm *A*T* AOL. If you are in the RTP area, we
are both "local".

Everyone else I see running an electric mower are running with a cord. If
you want me to, I will ask my neighbors their brand and opinions.

On 4/28/2014 1:27 PM, Cal Frye wrote:

I'm on my second Black and Decker push mower, corded type. I have a
small lawn, so avoiding running over the cord is not a major problem. I
won't advise on motor or batteries, but I can say B&D has a plastic shim
in the stack

Re: [EVDL] Recommendations for push mower motor?

2014-04-28 Thread nicklogan

The batteries in the Homelite battery mower I've been using for four years
gave out this spring so I went for the 56V EGO mower at Home Despot this
weekend since I had a $100 gift card already (still too pricey but I have
too many projects going already and couldn't bring myself to buy an ICE
mower). I've only used it once but like it so far - very lightweight since
it's almost all plastic. It has a 5 year overall warranty and three years on
the battery. Even though I have a fairly small yard I expect the battery
will give out about two weeks after the warranty ends. The battery and
charger design look like they came out of a Halo video game.



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Re: [EVDL] Recommendations for push mower motor?

2014-04-28 Thread Dennis Miles

about the plastic disk shearing off. replace it with a sheet metal disk to
fit the motor shaft then place a disk of leather between the new drive disk
and the blade hub, then when you hit a rock the blade slips and no damage
is done.

*Dennis Lee Miles *

*Director   **E.V.T.I. Inc.*

*E-Mail:*  *evprofes...@evprofessor.com* 

   *Phone #* *(863) 944-9913*

Dade City, Florida 33523

 USA




On Mon, Apr 28, 2014 at 3:45 PM, Michael Ross wrote:

> I have another battery from these people that seems just fine (after taking
> it apart to see inside)
>
>
> http://www.aliexpress.com/store/product/24V-40AH-LiFePO4-Battery-Pack-Electric-Bicycle-electric-Scooter-bicycle-E-Bike-Lithium-Ion-Long-life/328001_771068114.html
>
> This one is 24V 40Ah LFP and weighs 9kg.  $500 including shipping BMS and
> charger. 3 to 7 day delivery and the met that. These that 18650 cells with
> welded straps for conducting the juice.
>
> I think I will try to get a used 24V B&D instead of reworking my old bottom
> of the line MTD.
>
> I think my wife would love to have an electric mower.  She hates asking me
> to start them for her.  It would be nice not having all the oil checking
> and filling,   And as the current mower works - the rod knocking and
> smoking.  We have an acre of mostly flat yard - 40Ah would go a long ways
> and the charge time is about 2 hours.
>
>
> On Mon, Apr 28, 2014 at 3:25 PM, Peter Eckhoff  wrote:
>
> > Hello Mike,
> >
> > I'll second what Cal is saying below.  To get the nut off, you have to
> > place a wrench on the nut and "impact" it until the nut loosens.  I would
> > **not** use a compressed air impactor tool.  I use my fist.  Be careful
> > because everything is free wheeling.  If you leave your knuckles in the
> > path of the blade, your knuckles are going to get whacked.  There is no
> > other place to place another wrench unless you weld a nut to the top of
> the
> > motor shaft.
> >
> > Like Cal, I keep a set of several "small plastic blade insulators" on
> hand
> > which is how they are described in the User's Manual.  The word
> "insulator"
> > may seem like a misnomer but it is to "insulate" the shock of hitting a
> > rock from damaging the armature.
> >
> > I converted a corded B&D to cordless.  It uses 9 - 5 amphr 12 volt LA
> AGMs
> > to power the mower.  It is enough to do a 7K square foot lawn.  What used
> > to take me 1.5 hours to do when corded, now takes about 45 minutes.
> >
> > I use a 1.3 amphr AGM for the tripping a small contactor.  This battery
> > goes down faster than the pack.  I would use about a 2 amphr battery for
> > each hour the contactors are tripped.  That should give you plenty of
> > cushion.
> >
> > I wrote a two part article for the Electric Auto Association's Current
> > Events magazine.  I have the submittals in PDF format. The B&D motors are
> > DC universal motors that operate at 120 volts.  The corded version has a
> > full rectifier bridge on a little heat sink.  It was mainly a rewiring
> job
> > to bypass the rectifier.
> >
> > I think the AGMs are the wrong type of battery for this project.
> Normally,
> > when not cutting the lawn, the motor consumes about 4 amps.  When cutting
> > thick grass, the motor consumes about 8 amps. It can spike to 10 amps in
> > real thick grass or when the mower clogs up in thick grass.
> >
> > I have been contemplating upgrading this mower to Lithium.  A set of 40 -
> > 3.2 volt 10 amphr would be about right for an hour's worth of cutting and
> > still have some reserve.  I saw an ad for Shorai 12Volt 12 Amphr
> batteries
> >  for $117 each and they weigh about 1.7 pounds.  My 5.0 amphr batteries
> > weigh 3.5 pounds each for an added weight (starter + pack support +
> > contactor) of 35 pounds onto a mower that weighs 47 pounds for a total of
> > around 82 pounds.  This is about the weight of an ICE push mower.  Twelve
> > Shorai batteries would be around 20 pounds.  The mower would be lighter
> and
> > so would your wallet of $1400 plus shipping.
> >
> > I have thought about purchasing 4 - 100 amphr CALB batteries and then use
> > a converter to step up the voltage to 120 volts.  At an efficiency of
> 85%,
> > the amphrs to the motor would be about 8.5.  I am not sure if a converter
> > could handle that much amperage.  I was going to do some more homework
> > before asking the experts here. Four CALB batteries would be about 600
> > dollars and a converter would run in the lower several hundreds.  The
> > savings would be substantial but I am not sure if the electronics would
> > handle the load.
> >
> > The other thought would be to run the 4 CALBs into an inverter and leave
> > the rectifier bridge intact.  The inefficiency of the inverter plus the
> > inefficiency of the rectifier bridge would likely sap the pack of a lot
> of
> > useful energy.  I think this would be a nonstarter.
> >
> > I know of someone using a self contained electric mower.  You might want
> > to shoot him an email at theadm *A*T* AOL.  If you ar

Re: [EVDL] Recommendations for push mower motor?

2014-04-28 Thread Cor van de Water

I agree on starting with a "needs new battery" type cordless mower.
I picked up a 36V WORX WG788 which also is supposed to have
"IntelliCut" which appears to be a hall sensor and magnet on the back
of the motor's axle, so the controller can regulate the power to the
motor for constant mowing speed, no matter the load.
Unfortunately this controller let the smoke out and I have considered
getting a cheap 36V eBike controller as well as just using the PM
motor directly on a new pack, but found that the inrush current is
quite significant so a controller or current limit of sorts is going to
be needed to avoid blowing things up.
However, my yard is so small that for the time being, I can easily
mow it with a real (reel-type) push mower, so the e-mower remains one
of the many projects waiting for time or another loving home.
I checked and the PM motor is fine, in case anybody is interested,
it is located in the south of the SF bay area, aka Silicon Valley.

Cor van de Water
Chief Scientist
Proxim Wireless Corporation http://www.proxim.com
Email: cwa...@proxim.com Private: http://www.cvandewater.info
Skype: cor_van_de_water Tel: +1 408 383 7626

-Original Message-
From: ev-boun...@lists.evdl.org [mailto:ev-boun...@lists.evdl.org] On
Behalf Of Michael Ross
Sent: Monday, April 28, 2014 12:46 PM
To: Electric Vehicle Discussion List
Subject: Re: [EVDL] Recommendations for push mower motor?

I have another battery from these people that seems just fine (after
taking
it apart to see inside)

http://www.aliexpress.com/store/product/24V-40AH-LiFePO4-Battery-Pack-El
ectric-Bicycle-electric-Scooter-bicycle-E-Bike-Lithium-Ion-Long-life/328
001_771068114.html

This one is 24V 40Ah LFP and weighs 9kg.  $500 including shipping BMS
and
charger. 3 to 7 day delivery and the met that. These that 18650 cells
with
welded straps for conducting the juice.

I think I will try to get a used 24V B&D instead of reworking my old
bottom
of the line MTD.

I think my wife would love to have an electric mower.  She hates asking
me
to start them for her.  It would be nice not having all the oil checking
and filling,   And as the current mower works - the rod knocking and
smoking.  We have an acre of mostly flat yard - 40Ah would go a long
ways
and the charge time is about 2 hours.

On Mon, Apr 28, 2014 at 3:25 PM, Peter Eckhoff 
wrote:

> Hello Mike,
>
> I'll second what Cal is saying below.  To get the nut off, you have to
> place a wrench on the nut and "impact" it until the nut loosens.  I
would
> **not** use a compressed air impactor tool.  I use my fist.  Be
careful
> because everything is free wheeling.  If you leave your knuckles in
the
> path of the blade, your knuckles are going to get whacked.  There is
no
> other place to place another wrench unless you weld a nut to the top
of the
> motor shaft.
>
> Like Cal, I keep a set of several "small plastic blade insulators" on
hand
> which is how they are described in the User's Manual.  The word
"insulator"
> may seem like a misnomer but it is to "insulate" the shock of hitting
a
> rock from damaging the armature.
>
> I converted a corded B&D to cordless.  It uses 9 - 5 amphr 12 volt LA
AGMs
> to power the mower.  It is enough to do a 7K square foot lawn.  What
used
> to take me 1.5 hours to do when corded, now takes about 45 minutes.
>
> I use a 1.3 amphr AGM for the tripping a small contactor.  This
battery
> goes down faster than the pack.  I would use about a 2 amphr battery
for
> each hour the contactors are tripped.  That should give you plenty of
> cushion.
>
> I wrote a two part article for the Electric Auto Association's Current
> Events magazine.  I have the submittals in PDF format. The B&D motors
are
> DC universal motors that operate at 120 volts.  The corded version has
a
> full rectifier bridge on a little heat sink.  It was mainly a rewiring
job
> to bypass the rectifier.
>
> I think the AGMs are the wrong type of battery for this project.
Normally,
> when not cutting the lawn, the motor consumes about 4 amps.  When
cutting
> thick grass, the motor consumes about 8 amps. It can spike to 10 amps
in
> real thick grass or when the mower clogs up in thick grass.
>
> I have been contemplating upgrading this mower to Lithium.  A set of
40 -
> 3.2 volt 10 amphr would be about right for an hour's worth of cutting
and
> still have some reserve.  I saw an ad for Shorai 12Volt 12 Amphr
batteries
>  for $117 each and they weigh about 1.7 pounds.  My 5.0 amphr
batteries
> weigh 3.5 pounds each for an added weight (starter + pack support +
> contactor) of 35 pounds onto a mower that weighs 47 pounds for a total
of
> around 82 pounds.  This is about the weight of an ICE push mower.
Twelve
> Shorai batteries would be around 20 pounds.  The mower would be

Re: [EVDL] Recommendations for push mower motor?

I have another battery from these people that seems just fine (after taking
it apart to see inside)

http://www.aliexpress.com/store/product/24V-40AH-LiFePO4-Battery-Pack-Electric-Bicycle-electric-Scooter-bicycle-E-Bike-Lithium-Ion-Long-life/328001_771068114.html

This one is 24V 40Ah LFP and weighs 9kg.  $500 including shipping BMS and
charger. 3 to 7 day delivery and the met that. These that 18650 cells with
welded straps for conducting the juice.

I think I will try to get a used 24V B&D instead of reworking my old bottom
of the line MTD.

I think my wife would love to have an electric mower.  She hates asking me
to start them for her.  It would be nice not having all the oil checking
and filling,   And as the current mower works - the rod knocking and
smoking.  We have an acre of mostly flat yard - 40Ah would go a long ways
and the charge time is about 2 hours.


On Mon, Apr 28, 2014 at 3:25 PM, Peter Eckhoff  wrote:

> Hello Mike,
>
> I'll second what Cal is saying below.  To get the nut off, you have to
> place a wrench on the nut and "impact" it until the nut loosens.  I would
> **not** use a compressed air impactor tool.  I use my fist.  Be careful
> because everything is free wheeling.  If you leave your knuckles in the
> path of the blade, your knuckles are going to get whacked.  There is no
> other place to place another wrench unless you weld a nut to the top of the
> motor shaft.
>
> Like Cal, I keep a set of several "small plastic blade insulators" on hand
> which is how they are described in the User's Manual.  The word "insulator"
> may seem like a misnomer but it is to "insulate" the shock of hitting a
> rock from damaging the armature.
>
> I converted a corded B&D to cordless.  It uses 9 - 5 amphr 12 volt LA AGMs
> to power the mower.  It is enough to do a 7K square foot lawn.  What used
> to take me 1.5 hours to do when corded, now takes about 45 minutes.
>
> I use a 1.3 amphr AGM for the tripping a small contactor.  This battery
> goes down faster than the pack.  I would use about a 2 amphr battery for
> each hour the contactors are tripped.  That should give you plenty of
> cushion.
>
> I wrote a two part article for the Electric Auto Association's Current
> Events magazine.  I have the submittals in PDF format. The B&D motors are
> DC universal motors that operate at 120 volts.  The corded version has a
> full rectifier bridge on a little heat sink.  It was mainly a rewiring job
> to bypass the rectifier.
>
> I think the AGMs are the wrong type of battery for this project. Normally,
> when not cutting the lawn, the motor consumes about 4 amps.  When cutting
> thick grass, the motor consumes about 8 amps. It can spike to 10 amps in
> real thick grass or when the mower clogs up in thick grass.
>
> I have been contemplating upgrading this mower to Lithium.  A set of 40 -
> 3.2 volt 10 amphr would be about right for an hour's worth of cutting and
> still have some reserve.  I saw an ad for Shorai 12Volt 12 Amphr batteries
>  for $117 each and they weigh about 1.7 pounds.  My 5.0 amphr batteries
> weigh 3.5 pounds each for an added weight (starter + pack support +
> contactor) of 35 pounds onto a mower that weighs 47 pounds for a total of
> around 82 pounds.  This is about the weight of an ICE push mower.  Twelve
> Shorai batteries would be around 20 pounds.  The mower would be lighter and
> so would your wallet of $1400 plus shipping.
>
> I have thought about purchasing 4 - 100 amphr CALB batteries and then use
> a converter to step up the voltage to 120 volts.  At an efficiency of 85%,
> the amphrs to the motor would be about 8.5.  I am not sure if a converter
> could handle that much amperage.  I was going to do some more homework
> before asking the experts here. Four CALB batteries would be about 600
> dollars and a converter would run in the lower several hundreds.  The
> savings would be substantial but I am not sure if the electronics would
> handle the load.
>
> The other thought would be to run the 4 CALBs into an inverter and leave
> the rectifier bridge intact.  The inefficiency of the inverter plus the
> inefficiency of the rectifier bridge would likely sap the pack of a lot of
> useful energy.  I think this would be a nonstarter.
>
> I know of someone using a self contained electric mower.  You might want
> to shoot him an email at theadm *A*T* AOL.  If you are in the RTP area, we
> are both "local".
>
> Everyone else I see running an electric mower are running with a cord.  If
> you want me to, I will ask my neighbors their brand and opinions.
>
>
> On 4/28/2014 1:27 PM, Cal Frye wrote:
>
>> I'm on my second Black and Decker push mower, corded type. I have a
>> small lawn, so avoiding running over the cord is not a major problem. I
>> won't advise on motor or batteries, but I can say B&D has a plastic shim
>> in the stack of washers holding the blade to the motor shaft. Said shim
>> has raised edges which grip either side of the blade, and an opposing
>> pair of edges which

Re: [EVDL] Recommendations for push mower motor?

2014-04-28 Thread Peter Eckhoff


Hello Mike,

I'll second what Cal is saying below.  To get the nut off, you have to 
place a wrench on the nut and "impact" it until the nut loosens.  I 
would **not** use a compressed air impactor tool.  I use my fist.  Be 
careful because everything is free wheeling.  If you leave your knuckles 
in the path of the blade, your knuckles are going to get whacked.  There 
is no other place to place another wrench unless you weld a nut to the 
top of the motor shaft.


Like Cal, I keep a set of several "small plastic blade insulators" on 
hand which is how they are described in the User's Manual.  The word 
"insulator" may seem like a misnomer but it is to "insulate" the shock 
of hitting a rock from damaging the armature.


I converted a corded B&D to cordless.  It uses 9 - 5 amphr 12 volt LA 
AGMs to power the mower.  It is enough to do a 7K square foot lawn.  
What used to take me 1.5 hours to do when corded, now takes about 45 
minutes.


I use a 1.3 amphr AGM for the tripping a small contactor.  This battery 
goes down faster than the pack.  I would use about a 2 amphr battery for 
each hour the contactors are tripped.  That should give you plenty of 
cushion.


I wrote a two part article for the Electric Auto Association's Current 
Events magazine.  I have the submittals in PDF format. The B&D motors 
are DC universal motors that operate at 120 volts.  The corded version 
has a full rectifier bridge on a little heat sink.  It was mainly a 
rewiring job to bypass the rectifier.


I think the AGMs are the wrong type of battery for this project. 
Normally, when not cutting the lawn, the motor consumes about 4 amps.  
When cutting thick grass, the motor consumes about 8 amps. It can spike 
to 10 amps in real thick grass or when the mower clogs up in thick grass.


I have been contemplating upgrading this mower to Lithium.  A set of 40 
- 3.2 volt 10 amphr would be about right for an hour's worth of cutting 
and still have some reserve.  I saw an ad for Shorai 12Volt 12 Amphr 
batteries  for $117 each and they weigh about 1.7 pounds.  My 5.0 amphr 
batteries weigh 3.5 pounds each for an added weight (starter + pack 
support + contactor) of 35 pounds onto a mower that weighs 47 pounds for 
a total of around 82 pounds.  This is about the weight of an ICE push 
mower.  Twelve Shorai batteries would be around 20 pounds.  The mower 
would be lighter and so would your wallet of $1400 plus shipping.


I have thought about purchasing 4 - 100 amphr CALB batteries and then 
use a converter to step up the voltage to 120 volts.  At an efficiency 
of 85%, the amphrs to the motor would be about 8.5.  I am not sure if a 
converter could handle that much amperage.  I was going to do some more 
homework before asking the experts here. Four CALB batteries would be 
about 600 dollars and a converter would run in the lower several 
hundreds.  The savings would be substantial but I am not sure if the 
electronics would handle the load.


The other thought would be to run the 4 CALBs into an inverter and leave 
the rectifier bridge intact.  The inefficiency of the inverter plus the 
inefficiency of the rectifier bridge would likely sap the pack of a lot 
of useful energy.  I think this would be a nonstarter.


I know of someone using a self contained electric mower.  You might want 
to shoot him an email at theadm *A*T* AOL.  If you are in the RTP area, 
we are both "local".


Everyone else I see running an electric mower are running with a cord.  
If you want me to, I will ask my neighbors their brand and opinions.


On 4/28/2014 1:27 PM, Cal Frye wrote:

I'm on my second Black and Decker push mower, corded type. I have a
small lawn, so avoiding running over the cord is not a major problem. I
won't advise on motor or batteries, but I can say B&D has a plastic shim
in the stack of washers holding the blade to the motor shaft. Said shim
has raised edges which grip either side of the blade, and an opposing
pair of edges which grip in turn a keyed, square washer above the blade.
This square washer is driven by the motor, and the blade is driven by
the plastic shim. Hit too hard an obstacle, and the plastic edges shear
off and the blade rotates freely.

This is effective, but is also a wear point, and I've learned to buy the
shims by the half-dozen. My eyes don't always find the rocks in the yard
before the blade does :-(

Best regards,
-- Cal Frye, www.calfrye.com
/Be an Internet Sceptic/  Stop. Think. Connect.
www.stopthinkconnect.org - Be at least as safe on the
Internet as you are crossing the street!

"I sincerely believe that banking establishments are more dangerous than
standing armies." -- Thomas Jefferson, letter to John Taylor.




Michael Ross 
April 28, 2014 12:58 PM
I have an old simple ICE push mower, that might be worth converting.

...
What about the shock of the blade hitting something nearly immobile? That
is a lot of shock that small engines are able to handle - special
considerat

Re: [EVDL] Recommendations for push mower motor?

2014-04-28 Thread Chris Tromley

On Mon, Apr 28, 2014 at 2:01 PM, Lee Hart  wrote:

> On the blade hitting rocks: Copy the same setup they use on the ICE. They
> always have some kind of clutch setup so if the blade hits something, it
> can instantly stop while the clutch slips. Usually, the clutch is nothing
> but a big bolt that pinches the blade between a pair of friction washers.
>
> My last experience with an ICE mower (long ago) had a soft metal
square-section key between the blade hub and the shaft.  Hit a rock and
you'd shear the key before anything bent.  Made for kind of a hassle to get
it running again (a trip to the mower repair shop for the special soft
key), but it was cheaper to manufacture than the friction washer approach.

I'm a big fan of friction washers.  The three mower motors on my electric
tractor mount the blades this way.  I've hit lots of stuff and never had a
problem.

Chris
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Re: [EVDL] Recommendations for push mower motor?

2014-04-28 Thread Lee Hart


Michael Ross wrote:

I have an old simple ICE push mower, that might be worth converting.


I've done some conversions, both for myself and for friends.

A standard ICE push mower, or corded electric mower is easy to convert; 
but likely to be less than satisfactory to use. The weight of the 
batteries will make it a bear to push around. You'd want to use better 
wheels, and that gets to be a lot of work to change.


I converted a corded electric mower to battery by adding 60 2v 2.5ah 
lead-acid "D" cells. They were packaged into a donut-shaped box that sat 
around the existing 120vdc motor. The stock on/off switch operated a big 
relay that actually switched the motor. *Don't* use the stock switch to 
switch DC to the motor! It will fail almost immediately!


The batteries gave me a mowing time of 15-20 minutes. That was kind of 
short, but kept the mower from being too heavy.


A treadmill motor is a reasonable choice with a high voltage battery 
pack. They typically draw 5-15 amps. You will need at least 48v for 
reasonable speed.


I've also converted small riding mowers. They have the advantage of more 
room for batteries, and thus longer mowing times. They can also carry 
the weight better. The electric motor doesn't need to be even *remotely* 
as much horsepower as they advertise for ICE engines. We converted a 
Wheel Horse garden tractor where the 12hp gas engine was replaced with a 
1.5hp 36v electric motor. The electric was faster, and had more mowing 
power than the ICE.


Avoid mowers and tractors with hydrostatic drives. They are woefully 
inefficient. Get one with a mechanical transmission.


On the blade hitting rocks: Copy the same setup they use on the ICE. 
They always have some kind of clutch setup so if the blade hits 
something, it can instantly stop while the clutch slips. Usually, the 
clutch is nothing but a big bolt that pinches the blade between a pair 
of friction washers.


Golf carts and small industrial vehicles are common sources of electric 
24v to 48v DC motors.


You usually don't need a speed controller. With a PM motor, all you need 
is an on/off switch. A "start" switch that puts a resistor in series 
with the motor for starting can also help reduce the starting current surge.


--
If we knew what we were doing, it wouldn't be called research, would it?
-- Albert Einstein
--
Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm
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Re: [EVDL] Recommendations for push mower motor?

2014-04-28 Thread Cal Frye

I'm on my second Black and Decker push mower, corded type. I have a
small lawn, so avoiding running over the cord is not a major problem. I
won't advise on motor or batteries, but I can say B&D has a plastic shim
in the stack of washers holding the blade to the motor shaft. Said shim
has raised edges which grip either side of the blade, and an opposing
pair of edges which grip in turn a keyed, square washer above the blade.
This square washer is driven by the motor, and the blade is driven by
the plastic shim. Hit too hard an obstacle, and the plastic edges shear
off and the blade rotates freely.

This is effective, but is also a wear point, and I've learned to buy the
shims by the half-dozen. My eyes don't always find the rocks in the yard
before the blade does :-(

Best regards,
-- Cal Frye, www.calfrye.com
/Be an Internet Sceptic/  Stop. Think. Connect.
www.stopthinkconnect.org - Be at least as safe on the
Internet as you are crossing the street!

"I sincerely believe that banking establishments are more dangerous than
standing armies." -- Thomas Jefferson, letter to John Taylor.



> Michael Ross 
> April 28, 2014 12:58 PM
> I have an old simple ICE push mower, that might be worth converting.
>
> ...

> What about the shock of the blade hitting something nearly immobile? That
> is a lot of shock that small engines are able to handle - special
> consideration in the regard with electric motors?
>
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[EVDL] Recommendations for push mower motor?