EV Digest 3909
Topics covered in this issue include:
1) RE: Modular Charger
by "damon henry" <[EMAIL PROTECTED]>
2) Low-resistance tires ... are they as safe?
by W Bryan Andrews <[EMAIL PROTECTED]>
3) regbus control of non-rudman charger. (was: variac turn-on? maybe ot)
by Gravity Girl <[EMAIL PROTECTED]>
4) Re: Electric Sailboat conversion
by Neon John <[EMAIL PROTECTED]>
5) RE: Modular Charger
by "Grannes, Dean" <[EMAIL PROTECTED]>
6) Re: Nissan X-Trail FCV
by Fortunat Mueller <[EMAIL PROTECTED]>
7) Peukert's exponent for US-145s?
by Sherry Boschert <[EMAIL PROTECTED]>
8) Re: Modular Charger
by "Rich Rudman" <[EMAIL PROTECTED]>
9) Re: Measure Battery Interal Resistance
by Otmar <[EMAIL PROTECTED]>
10) Re: Modular Charger
by Lee Hart <[EMAIL PROTECTED]>
11) Re: Measure Battery Interal Resistance
by Nawaz Qureshi <[EMAIL PROTECTED]>
12) RE: Measure Battery Interal Resistance
by "Don Cameron" <[EMAIL PROTECTED]>
13) RE: Measure Battery Interal Resistance
by "Don Cameron" <[EMAIL PROTECTED]>
14) RE: Switched Capacitor Circuit for Charge Equalization
by "Don Cameron" <[EMAIL PROTECTED]>
15) Lifeline batteries
by Mike Barber <[EMAIL PROTECTED]>
16) Re: Lifeline batteries
by Christopher Zach <[EMAIL PROTECTED]>
17) RE: Measure Battery Interal Resistance
by "Roger Stockton" <[EMAIL PROTECTED]>
18) Re: Measure Battery Interal Resistance
by "Rich Rudman" <[EMAIL PROTECTED]>
19) Th!nk story on CBS
by Nick Carter <[EMAIL PROTECTED]>
20) RE: Lifeline batteries
by "Don Cameron" <[EMAIL PROTECTED]>
21) Re: Measure Battery Interal Resistance
by Victor Tikhonov <[EMAIL PROTECTED]>
22) RE: Lifeline batteries
by "damon henry" <[EMAIL PROTECTED]>
23) RE: Lifeline batteries
by "Roger Stockton" <[EMAIL PROTECTED]>
--- Begin Message ---
I think this is the best of both worlds and I'm very surprised that more
people haven't already implemented it.
From: Mike Chancey <[EMAIL PROTECTED]>
Reply-To: [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Subject: Modular Charger
Date: Fri, 12 Nov 2004 10:16:17 -0600
Hi folks,
Who is using modular chargers (one charger per battery) and how well have
they worked out? After playing all kinds of games with battery management
systems (Ruman Mk1s, PowerCheqs) I have been dreaming of the simplicity of
letting each battery have its own charger. My thoughts go like this:
Bulk charge using a large series charger (in my case a Zivan NG5 but could
be some big crude off board thing as well). Shutdown the charger using the
low battery alarm circuit on the E-meter when batteries are charged to 95%.
Then the little individual charger take over (say 5 amp units) and handle
the last 5% charge. Each battery gets just what it needs, and no battery
gets over charged. Away from home opportunity charging, just use the
little guys.
So what do you think? Anyone know a good source for a capable 12 volt 5
amp automatic charger at a good price?
Thanks,
Mike Chancey,
'88 Civic EV
'95 Solectria Force
Kansas City, Missouri
EV List Photo Album at: http://evalbum.com
My Electric Car at: http://www.geocities.com/electric_honda
Mid-America EAA chapter at: http://maeaa.org
Join the EV List at: http://www.madkatz.com/ev/evlist.html
--- End Message ---
--- Begin Message ---
Ye with much more experience,
I'm looking at putting some low-rolling-resistance tires on my
Voltsrabbit sometime in the near future. I'm concerned about this
idea, though, with a snowy mid-western winter around the corner.
Would these tires decrease my traction noticeably? It would seem
to give up resistance, you have to give up traction as well.
Thanks!
WB
--- End Message ---
--- Begin Message ---
Color me silly, but I am trying to take advantage of Rich's regbus on
his regulators without using one of his chargers.
I may be going about this the wrong way, however.
If there is a thermal overload on one of the regulators, one pin on the
regbus goes to +5v. The most it can put out is 100 milliamps.
I was thinking that to shut down the charger in thermal overload
conditions I could put a normally closed SSR on the DC side (should I
put it on the AC side of the charger?) that would open when the regbus
triggered the +5v. I figured on an SSR because they can handle nice
currents/voltages with a tiny triggering current compared to a regular
relay.
Each of my regs has a load-controlled fan, and my charger is a 3A
soneil, but I want to protect my investment. And since Rich was kind
enough to put the thermal sensing in there, I figured I'd take
advantage of it.
A bit about me: I know almost nothing about electronics but I can build
things pretty well if pointed in the right direction.
-Cristin
On Nov 12, 2004, at 10:28 AM, Lee Hart wrote:
cristin wrote:
I was looking at SSRs today, but having a helluva time finding
exactly what I need:
5v trigger with less than 100 milliamp draw
Normally closed
can switch 100V 10A
Normally closed is rare; almost all are normally open.
Also why only 100v? Are you switching DC? Most SSR "contacts" are AC
only, and so come in 120vac, 240vac, 480vac etc. voltage ratings.
If you want DC "contacts" and normally-closed, that is your problem;
you're looking for two uncommon options at once.
--
"Never doubt that the work of a small group of thoughtful, committed
citizens can change the world. Indeed, it's the only thing that ever
has!" -- Margaret Mead
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--
La Bola Ocho Magica dice: ME RESPUESTA ES NO
--- End Message ---
--- Begin Message ---
Sulfuric acid and salt react to produce sodium sulfate and chlorine gas.
Sea water in contact with electrolyte is a deadly serious concern in a
closed environment like a submarine. Probably not such a problem with a
recreational vessel. I imagine that by the time sufficient sea water is
on board to reach the batteries, the captain has other things to worry
about. :-)
John
On Fri, 12 Nov 2004 00:20:05 -0800, "Lawrence Rhodes" <[EMAIL PROTECTED]>
wrote:
>What causes explosions on boats is gasoline. That's why they use diesel.
>Diesel smells so electric is a real joy. Lawrence Rhodes......
>----- Original Message -----
>From: "Dave" <[EMAIL PROTECTED]>
>To: <[EMAIL PROTECTED]>
>Sent: Thursday, November 11, 2004 6:45 PM
>Subject: Re: Electric Sailboat conversion
>
>
>> Isn't there some sort of problem with batteries and salt water? I seem to
>> recall either explosions or poison gas.
>> David C. Wilker Jr.
>> USAF (RET)
>> ----- Original Message -----
>> From: "Shawn Waggoner" <[EMAIL PROTECTED]>
>> To: <[EMAIL PROTECTED]>
>> Sent: Thursday, November 11, 2004 6:42 PM
>> Subject: RE: Electric Sailboat conversion
>>
>>
>>>I am not affiliated with them but, there is a commercial company here in
>>> FL that installs electric drive systems in boats (mostly sail). They are
>>> up near Tampa, in Tarpon Springs. The company is Solomon Technologies
>>> (http://solomontechnologies.com/).
>>>
>>> They are installing BLDC motors and control systems. The company went
>>> public last year and claims a lot of proprietary technology; however, I
>>> have seen a couple of the catamarans they have installed drives in and
>>> its all pretty straightforward stuff. They replace the existing inboard
>>> engine(s) with a BLDC motor(s). Other than maybe the motor itself, all
>>> the rest is off-the-shelf stuff for BLDC drives. They claim special
>>> design considerations and magnet technology for the motors. They do nice
>>> work though. They are currently working with two cat builders to install
>>> the drives systems at the factories. This way you could order the boat
>>> with an electric drive. The two-motor setup on the cats is quite nice
>>> for maneuvering, two joystick controls make docking easy!
>>>
>>> The boats still require a generator to keep the batteries topped off and
>>> run all the heavy loads like reefers and A/C, but you can drag the props
>>> under sail and use the motor to regen and charge the batteries as well.
>>> Some builders are installing larger PV arrays to help with the
>>> recharging.
>>>
>>> One of the boats is built over in South Africa and I talked to one of
>>> the crew members who sailed it over. They said normally the diesel gen
>>> would run about 16 to 18hrs a day underway, with the PV and regen off
>>> the motors under sail, the diesel only 4 to 6 hrs. He said they want to
>>> increase the battery pack capacity and they only lost a little under a
>>> knot of speed dragging the props.
>>>
>>> It's almost perfect, the ability to travel, produce (or harness, in the
>>> case of sailboats) the energy for travel, and recharge all with
>>> alternative / renewable energy.
>>>
>>> Shawn Waggoner
>>> Florida EAA
>>>
>>> -----Original Message-----
>>> From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
>>> Behalf Of MYLES ANTHONY TWETE
>>> Sent: Thursday, November 11, 2004 18:25
>>> To: [EMAIL PROTECTED]
>>> Subject: Electric Sailboat conversion (was: RE: I love batts, Low
>>> costs!! was Re: I hate batteries, comments)
>>>
>>> Jerry Dycus stated:
>>>> So to conclude, while EV's and sailboats can cost too much, they don't
>>> have to if done right.
>>>
>>> There's a growing number of sailboat owners who are ditching their
>>> diesels in favor of going electric w/generator backup. Several are
>>> using ETEK or ADC motors, 1 or 2 banks of batts at 36-48v and a 2kw
>>> Honda EU2000i genset. Most of the discussions are taking place on the
>>> Electricboating and the Electricboats Yahoo Groups. Discussions also
>>> occur at the EBAA (Electric Boating Assoc. of America) site.
>>>
>>> http://groups.yahoo.com/group/electricboats/
>>> http://groups.yahoo.com/group/ElectricBoating/
>>> http://www.eboat.org/forum/
>>>
>>> These conversions are occurring for all the right reasons: energy
>>> efficiency, reduced noise and vibration, cost effectiveness and
>>> reliability.
>>>
>>> -Myles Twete, Electric Bargeboat "Reach of Tide"
>>>
>>>
>>
---
John De Armond
[EMAIL PROTECTED]
http://bellsouthpwp.net/j/o/johngd/
Cleveland, Occupied TN
--- End Message ---
--- Begin Message ---
Mike,
> Bulk charge using a large series charger (in my case a Zivan NG5 but
could
> be some big crude off board thing as well). Shutdown the charger
using the
> low battery alarm circuit on the E-meter when batteries are charged to
> 95%. Then the little individual charger take over (say 5 amp units)
and
> handle the last 5% charge. Each battery gets just what it needs, and
no
> battery gets over charged. Away from home opportunity charging, just
use
> the little guys.
That's exactly the system that I have on the Blue Phantom (my Rabbit).
I have a 132V pack (11 buddy-pairs of Optimas). I use a PFC-20 for bulk
charging up to about 150V. At the same time, I have 11 modular (ZAP)
chargers that are set to 14.4V. The PFC brings the voltage up
relatively quickly to 150V and then cuts out, leaving the modular
chargers to bring the batteries up those last few volts. I have Rudman
Regs on my batteries to prevent overcharging. The outlet that the ZAP
chargers is plugged into is powered via a push-button timer (from Home
Depot) that allows me to select 2, 4, 8, or 12-hour charges.
>From a user standpoint, it is easy. Just plug it in, push the timer
button, and forget it. The PFC quits charging after it hits 150V. The
ZAP chargers shut off when the timer expires. I can leave my car
"plugged in" indefinitely without worrying about overcharging. The only
inconvenience (if you could call it that) is that I have two plugs to
plug in, a standard 120V plug for the ZAPs and a NEMA L6-30 locking
connector for the 240V line to the PFC.
>From a battery standpoint, I've had mixed results. I'm on my second
pack, but this pack was bought almost intact from someone who had bought
a bunch of Optimas for a conversion and then never finished his project.
They had been sitting in his garage for about a year, and were
unbalanced to begin with. I have at least two buddy pairs that are
weak, one of which is almost unusable, as it reverses every time I take
the car out. The only reason I am getting by on this pack is that my
commute is only four miles daily (roundtrip) to the train station. The
longest trip I make regularly is about seven miles roundtrip. At this
rate, I figure I can put off getting a new pack for another year or two.
I do have a Lee Hart Battery Balancer. It is a very nice system. It
worked great for a little while until it fried a relay board that I had
built for it. I haven't replaced it yet, but it's on my eventual
"to-do" list. Getting that working should help keep the bad pairs from
discharging too quickly.
My overall experience with modular chargers has also been mixed. It's
very convenient, and if the chargers are well-calibrated, your batteries
will stay in balance (assuming they start balanced). However, you do
need to check the chargers periodically to make sure their settings
haven't drifted. And it would be good to have a per-battery display,
like Lee's Balancer or JB Straubel's battery monitor
(http://www.jstraubel.com/BatteryMonitor/monitor.htm). This will tell
you whether an individual charger failed, so you don't drive off and
unknowingly ruin a battery (or battery pair). This has happened to me
several times over the past several years.
I'm interested to hear other people's experiences. I know John Bryan
has used ZAP chargers, and his Optima pack is still going strong (last I
heard) after several years. I hope he will chime in on this thread.
Dean Grannes
132V "Blue Phantom" '79 Rabbit
120V "Fire Chief" '59 MGA
--- End Message ---
--- Begin Message ---
Lawrence,
was it greenish ?
I assume when you say dealer plates, you mean
M-plates, right ?
I think that is one of ours (not really ours, but we
did all the hard work :)). There are four of these X
trail vehicles that live at the California Fuel Cell
Partnership in Sacramento. I assume this is one of
them.
I am glad to hear it is getting some use.
~fortunat
--- Lawrence Rhodes <[EMAIL PROTECTED]> wrote:
> I was driving across the Bay Bridge Wednesday night
> and fell in line behind
> a Nissan FCV. The name was X-Trail. It was big.
> Michigan dealer plates.
> Typical Japanese setup as far as the mirrors. A
> real concept car. God
> knows what they were doing driving it across
> country. Lawrence
> Rhodes.......
>
>
__________________________________
Do you Yahoo!?
Check out the new Yahoo! Front Page.
www.yahoo.com
--- End Message ---
--- Begin Message ---
Does anyone happen to know the typical Peukert's
exponent for US-145 lead acid batteries? I just
swapped these into my Rabbit to replace T-145s, and
the e-meter manual says the typical Peukert's for
T-145s is 1.14. I'm assuming it's about the same for
US-145s, but does anyone know?
thanks,
Sherry
San Francisco
__________________________________
Do you Yahoo!?
Check out the new Yahoo! Front Page.
www.yahoo.com
--- End Message ---
--- Begin Message ---
The nasty was cheap, affordable and didn't leave you with X-1 perfectly
charged batteries. The -1 was of course fully discharged... and this went
negative in like a mile of driving. The concept works....But you X times the
possibilities of charger fails.
Maybe you should mess with some Mk2B regs... alot has changed.
----- Original Message -----
From: "Mark Farver" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Friday, November 12, 2004 8:38 AM
Subject: Re: Modular Charger
> On Fri, 2004-11-12 at 10:16, Mike Chancey wrote:
> > Who is using modular chargers (one charger per battery) and how well
have
> > they worked out? After playing all kinds of games with battery
management
> > systems (Ruman Mk1s, PowerCheqs) I have been dreaming of the simplicity
of
> > letting each battery have its own charger. My thoughts go like this:
>
> Didn't Jason Hills' MR2 use modular Zapi chargers? IIRC he reported
> rapid failure of his Optimas.
>
> I think the challenge is find a small, affordable _smart_ charger. Most
> small chargers are pretty dumb.
>
> Mark
>
--- End Message ---
--- Begin Message ---
On Thu, 11 Nov 2004 22:15:33 -0800, Don Cameron
<[EMAIL PROTECTED]> wrote:
Is there an "easy" way to measure a battery's internal resistance? I am
measuring the voltage drop with a variety of loads, but I cannot get a
"definitive" answer.
thanks
> Don
The simple way it to just short the battery, and measure the current.
Then R = (1/2 the battery nominal voltage) divided by the current.
For example a Orbital probably puts out 3600 amps when shorted,
divide 6V by 3600 amps and you get 1.6 milliohms.
:-)
I'm just kidding.
Really, DO NOT DO THAT! Don't even think of it.
Couldn't resist. :-)
--
-Otmar-
http://www.CafeElectric.com
Mailto:[EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
Mike Chancey wrote:
> Who is using modular chargers (one charger per battery) and how
> well have they worked out?
I've done it on and off. The big problem is to find a *reliable* modular
charger. Most chargers are built to consumer-grade specs. They means
they assume it won't be used all that often, so they don't have to be
very reliable. A typical car battery charger might get used 100 times in
10 years. So, if 50% of them die after 100 uses, most customers wouldn't
care.
But in EV usage, you'd put that many cycles on them in a few months. And
if there are 10 of them and you have a 50% failure rate per 100 uses,
you'll have 1 or 2 of them dying every month!
So, you need a charger that is *drastically* more reliable. That's going
to be expensive! This is what stops most people from taking the modular
charger route.
When I've had success with modular chargers, it's been when the
circumstances allowed for a very reliable design. One of them is in a
rechargeable flashlight that I built over 15 years ago. It has four
Gates 2v 2.5ah gel cells. The charger is a transformer with two
center-tapped 6.3vac secondaries (3.15v each side of center tap). With
its two 115vac primaries in series, each secondary is actually 1.9vac
no-load. Rectified with a diode, this produces (1.9 x 1.4) - 0.4v =
2.26v/cell. So, each cell has its own winding and diode. The four cells
track because the transformer secondary voltages are automatically the
same. It's very reliable because it's so simple.
Another case was where I used Vicor modules, one per battery. They have
an extremely low failure rate (MTBF > 100,000 hours), but are also very
expensive (like $150 each).
--
"Never doubt that the work of a small group of thoughtful, committed
citizens can change the world. Indeed, it's the only thing that ever
has!" -- Margaret Mead
--
Lee A. Hart 814 8th Ave N Sartell MN 56377 leeahart_at_earthlink.net
--- End Message ---
--- Begin Message ---
Hi:
Perhaps too much emphasis is place on the "internal resistance" and how
to measure it. The reasons it is difficult in lead/acid batteries are:
The internal resistance is composed of several components: the ohmic
part composed of the resistance in the grids and the ionic conductivity,
and the Faradaic part are the dominant variables.
The ohmic part is continuously changing upon charge and discharge and is
composed of the resistance in the grids (very slow to change) and the
resistance in the active material. The latter is very sensitive to the
state of charge because the lead sulfate is an electronic insulator. As
more is formed, the resistance goes up. The ionic conductivity of the
acid is another factor and is function of the changing concentration of
the acid. Another factor is the temperature.
Given the nature of the beast, you cannot obtain a fixed reproducible
number, as it can change by an order of magnitude by the variables
mentioned above.
The only time it can be somewhat accurate in the ohmic sense is that you
measure it after fully charging only, at a constant temperature and you
use two high discharge currents and measure the two corresponding
Voltages at fixed duration of time, the use Ohm's law to calculate the
resistance. . Even then, there may be 25% margin of error.
It is best to actually empirically measure the Voltage drop (or sag)
under actual use conditions.
Sincerely
Nawaz Qureshi
begin:vcard
fn:Nawaz Qureshi
n:Qureshi;Nawaz
org:U. S. Battery Manufacturing Company
adr;dom:;;1675 Sampson Avenue;Corona;CA;92879
email;internet:[EMAIL PROTECTED]
title:Vice - President of Engineering
tel;work:951-371-8090
tel;fax:951-371-4671
url:http://www.usbattery.com
version:2.1
end:vcard
--- End Message ---
--- Begin Message ---
=:-0 I wish you warned me!!!! That really hurt! My 10Amp DMM burnt to a
crisp...
(just kidding)
Don
Victoria, BC, Canada
See the New Beetle EV Conversion Web Site at
www.cameronsoftware.com/ev/
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Otmar
Sent: November 12, 2004 10:51 AM
To: [EMAIL PROTECTED]
Subject: Re: Measure Battery Interal Resistance
>On Thu, 11 Nov 2004 22:15:33 -0800, Don Cameron
><[EMAIL PROTECTED]> wrote:
>> Is there an "easy" way to measure a battery's internal resistance? I
>> am measuring the voltage drop with a variety of loads, but I cannot
>> get a "definitive" answer.
>>
>> thanks
>>
> > Don
The simple way it to just short the battery, and measure the current.
Then R = (1/2 the battery nominal voltage) divided by the current.
For example a Orbital probably puts out 3600 amps when shorted, divide 6V by
3600 amps and you get 1.6 milliohms.
:-)
I'm just kidding.
Really, DO NOT DO THAT! Don't even think of it.
Couldn't resist. :-)
--
-Otmar-
http://www.CafeElectric.com
Mailto:[EMAIL PROTECTED]
--- End Message ---
--- Begin Message ---
What are you thinking I am going to use the battery internal resistance for?
My purpose for measuring battery internal resistance is to predict battery
performance. Here is the paper: http://www.alber.com/Docs/PredictBatt.pdf
The intention is to measure the resistance periodically (approx every couple
of months), in a somewhat controlled environment (e.g. fully charged,
constant temperature) to record and predict battery performance.
Where do you get the 25% margin of error figure from?
Don
Victoria, BC, Canada
See the New Beetle EV Conversion Web Site at
www.cameronsoftware.com/ev/
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Nawaz Qureshi
Sent: November 12, 2004 11:20 AM
To: [EMAIL PROTECTED]; EVList
Subject: Re: Measure Battery Interal Resistance
Hi:
Perhaps too much emphasis is place on the "internal resistance" and how to
measure it. The reasons it is difficult in lead/acid batteries are:
The internal resistance is composed of several components: the ohmic part
composed of the resistance in the grids and the ionic conductivity, and the
Faradaic part are the dominant variables.
The ohmic part is continuously changing upon charge and discharge and is
composed of the resistance in the grids (very slow to change) and the
resistance in the active material. The latter is very sensitive to the state
of charge because the lead sulfate is an electronic insulator. As more is
formed, the resistance goes up. The ionic conductivity of the acid is
another factor and is function of the changing concentration of the acid.
Another factor is the temperature.
Given the nature of the beast, you cannot obtain a fixed reproducible
number, as it can change by an order of magnitude by the variables mentioned
above.
The only time it can be somewhat accurate in the ohmic sense is that you
measure it after fully charging only, at a constant temperature and you use
two high discharge currents and measure the two corresponding Voltages at
fixed duration of time, the use Ohm's law to calculate the resistance. .
Even then, there may be 25% margin of error.
It is best to actually empirically measure the Voltage drop (or sag) under
actual use conditions.
Sincerely
Nawaz Qureshi
--- End Message ---
--- Begin Message ---
This is am interesting paper. Maybe one could be constructed using a series
of relays - instead of the actual circuit...
(all this speculation coming from a non-EE)
Don
Victoria, BC, Canada
See the New Beetle EV Conversion Web Site at
www.cameronsoftware.com/ev/
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Rod Hower
Sent: November 12, 2004 7:28 AM
To: [EMAIL PROTECTED]
Subject: Re: Switched Capacitor Circuit for Charge Equalization
A good friend of mine is working on that system.
Last time we talked he's not using it on EV size batteries yet. I'll let
the list know when they start doing extensive testing with larger batteries.
Rod
--- Don Cameron <[EMAIL PROTECTED]> wrote:
> In researching the web, I stumbled across a paper called "Switched
> Capacitor System for Automatic Series Battery Equalization", located
> on:
> http://www.smartsparkenergy.com/pdf/batteq1.pdf
>
> I looked through the archives but could not find any reference to
> anyone using this type of a circuit for battery balancing.
> Has anyone tried this?
> The company Smart Spark Energy builds a unit, but appears only for OEM
> use.
>
>
> Don
>
>
>
--- End Message ---
--- Begin Message ---
I've been researching what it would take to build an AC EV. So far I have
settled on using one of the Siemens automotive motors (hopefully able to find a
surplus one on ebay from Ford's EV ranger project). The problem was that to
get the rated max torque and hp from these motors, you would need around 350V.
I didn't want to have 2000lbs of batteries, so I had a dilemma.
I think that I found a solution in Lifeline's marine deep cycle AGM batteries.
Here's a link:
http://www.lifelinebatteries.com/marine.asp
I would be interested in using the smallest, the GPL-U1T. It only weighs
24lbs, puts out 12V, 33Ah, and has 325 cranking amps at 68 deg F. If I used 34
of these to get 408V, I would be able to get the max hp and torque out of the
Siemens motor, and my pack would only weigh 816 lbs.
I have never built an EV before... how do these numbers sound as far as pack
voltage and pack weight? I know the amp hours are small, but I thought the
power output of the pack would compensate.
Has anyone ever used the Lifeline batteries before?
---------------------------------
Do you Yahoo!?
Check out the new Yahoo! Front Page. www.yahoo.com
--- End Message ---
--- Begin Message ---
Voltage sag might be a question with that many floodeds; part of the
reason high voltage EV's like AGMs.
24lbs for 33Ah is not too farm from my Genesis 26ah batteries (21lbs,
26ah 10hr rated). I wonder how they would handle things like overcharge
and drift.
Chris
Mike Barber wrote:
I've been researching what it would take to build an AC EV. So far I have
settled on using one of the Siemens automotive motors (hopefully able to find a
surplus one on ebay from Ford's EV ranger project). The problem was that to
get the rated max torque and hp from these motors, you would need around 350V.
I didn't want to have 2000lbs of batteries, so I had a dilemma.
I think that I found a solution in Lifeline's marine deep cycle AGM batteries.
Here's a link:
http://www.lifelinebatteries.com/marine.asp
I would be interested in using the smallest, the GPL-U1T. It only weighs
24lbs, puts out 12V, 33Ah, and has 325 cranking amps at 68 deg F. If I used 34
of these to get 408V, I would be able to get the max hp and torque out of the
Siemens motor, and my pack would only weigh 816 lbs.
I have never built an EV before... how do these numbers sound as far as pack
voltage and pack weight? I know the amp hours are small, but I thought the
power output of the pack would compensate.
Has anyone ever used the Lifeline batteries before?
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Don Cameron [mailto:[EMAIL PROTECTED] wrote:
> My purpose for measuring battery internal resistance is to
> predict battery performance. Here is the paper:
> http://www.alber.com/Docs/PredictBatt.pdf
Interesting. Here is another:
<http://www.powerpulse.net/powerpulse/archive/pdf/aa_062801a.pdf>
And, here is Isidor Buchman's (Cadex's) take on it:
<http://www.batteryuniversity.com/print-parttwo-42A.htm>
I'm pretty sure I previously came across a paper claiming that a simple
resistance measurement was *not* a good predictor of battery health (and
it presented study results to back up the claims). Unfortunately I
can't locate it now. I suspect some of the difference may be a subtle
distinction between measurement of resistance vs impedance.
LEM presented a paper at the 2004 Advancements in Battery Charging,
Monitoring & Testing symposium describing the theory behind their
'frequency response analysis' technique for evaluating/predicting
battery health (again lead-acid only, AFAIK). The battery impedance
model they refer to is the Randles model:
Cdl
+-------||------+
Rm Re | |
---^^^^---^^^^---+ +---
| Rct WI |
+--^^^^---^^^^--+
where:
Rm = metallic resistance (post, bus bar, gid and paste)
Re = electrolyte resistance
Rct = charge transfer resistance (electrolyte/plate interface)
Cdl = double layer capacitance
WI = Warburg impedance (mass transport impedance, not present during
discharge)
LEM's data shows that while Re, Rm, and Rct all increase gradually over
time as capacity is lost (very slowly at first, but increasingly rapidly
near the end of life), Cdl shows a much more pronounced *decrease* much
earlier and is therefore a better predictor of impending battery
failure.
I haven't tried searching it up, but you might try googling "LEM
Integrated Cell Management transducer" to see if you can get further
information on this technique.
> The intention is to measure the resistance periodically
> (approx every couple of months), in a somewhat controlled
> environment (e.g. fully charged, constant temperature) to
> record and predict battery performance.
As per the paper I reference above, it is suggested that since your
batteries will not likely be in a temperature controlled environment you
should compare the cell resistance measurements to the pack average
rather than to some absolute reference value (since the cells in the
pack should tend to be at about the same temperaure during the test,
even if that temperature differs from that of the reference value).
You might consider one of the Midtronics handheld conductance testers
for this purpose. Even a 'basic' unit that reads out a CCA estimate
rather than a resistance or conductance value would probably be just
fine for this purpose. You don't really care about the units, just how
the values compare to the average for the pack (and perhaps how they
compare to the values when the pack was new).
One word of warning: these devices/methods largely assume you are
testing lead acid batteries and will not necessarily predict the
behaviour of other chemistries. For instance, a FAQs document on the
Midtronics site specifically states that the conductance value is not
useful for predicting the performance of NiCd cells (the conductance
tends to remain fine until the cell fails castastrophically). I'm
pretty sure you intend to use a LiIon pack, and so caution that it may
not yet be established that conductance/impedance/resistance testing is
of any predictive value at all for that chemistry.
Cheers,
Roger.
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----- Original Message -----
From: "Otmar" <[EMAIL PROTECTED]>
To: <[EMAIL PROTECTED]>
Sent: Friday, November 12, 2004 10:50 AM
Subject: Re: Measure Battery Interal Resistance
> >On Thu, 11 Nov 2004 22:15:33 -0800, Don Cameron
> ><[EMAIL PROTECTED]> wrote:
> >> Is there an "easy" way to measure a battery's internal resistance? I
am
> >> measuring the voltage drop with a variety of loads, but I cannot get a
> >> "definitive" answer.
> >>
> >> thanks
> >>
> > > Don
>
> The simple way it to just short the battery, and measure the current.
> Then R = (1/2 the battery nominal voltage) divided by the current.
> For example a Orbital probably puts out 3600 amps when shorted,
> divide 6V by 3600 amps and you get 1.6 milliohms.
>
> :-)
>
> I'm just kidding.
>
> Really, DO NOT DO THAT! Don't even think of it.
>
> Couldn't resist. :-)
> --
> -Otmar-
> http://www.CafeElectric.com
> Mailto:[EMAIL PROTECTED]
>
Why not you Wuss!!
Geez the great Otmar is chicken...... What is the world coming to???
For real ,The Battery blaster that we DID check the Orbitals with ... pulled
1850 to 2000 amps, or about %60 the short circuit rating.
What you do is start with a fully charged battery, and hit it with 50 amps..
and record the voltage and amps with as much accuracy as you can. Then hit
it with as much amps as you dare, and record it with as much resolution as
you can. The difference in sag show the internal resistance and you can
calculate the Peukerts with this.
Joe and I did 10 amps and 500 amp on a Red Top years ago, and got pretty
good results.
And yes becarfull. We have opened batteries doing this. Just don't do it
long, and think through what you will do if the test setup gets in
trouble... Burning Graphite piles are wired, but predictable..
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I just received the following from Steve Fyffe.
Feedback to [EMAIL PROTECTED]
--------------------------------------------------
http://www.broadcastingcable.com/index.asp?layout=articlePrint&articleID=CA4
79935
<link>
w w w . b r o a d c a s t i n g c a b l e . c o m
----------
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By Allison Romano -- Broadcasting & Cable, 11/12/2004 8:52:00 AM
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Hewitt plans to do four shows a year.
<<< Back | Print
© 2004, Reed Business Information, a division of Reed Elsevier Inc. All
Rights Reserved.
Akilah Monifa
Director of Communications
CBS 5/UPN Bay Area
KPIX/KBHK Television
855 Battery St.
San Francisco, CA 94111-1597
[EMAIL PROTECTED]
415 765 8842
415 760 0688 mobile
415 765 8860 fax
http://www.cbs5.com
http://www.upnbayarea.com
--------------------------------------------------
Dr Nick Carter,
Owner, npc Imaging, 2228 Magowan Drive, Santa Rosa, CA 95405 USA
[EMAIL PROTECTED] Tel/fax: +1 (707) 573 9361
http://www.npcimaging.com
ex-Th!nk City EV driver
President, North Bay Electric Auto Association
"Spare the air every day - drive electric!"
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Do you know if they are the original battery manufacturer? Or are they
relabeled brand from another manufacturer?
Don
Victoria, BC, Canada
See the New Beetle EV Conversion Web Site at
www.cameronsoftware.com/ev/
-----Original Message-----
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On
Behalf Of Mike Barber
Sent: November 12, 2004 12:23 PM
To: [EMAIL PROTECTED]
Subject: Lifeline batteries
I've been researching what it would take to build an AC EV. So far I have
settled on using one of the Siemens automotive motors (hopefully able to
find a surplus one on ebay from Ford's EV ranger project). The problem was
that to get the rated max torque and hp from these motors, you would need
around 350V. I didn't want to have 2000lbs of batteries, so I had a
dilemma.
I think that I found a solution in Lifeline's marine deep cycle AGM
batteries. Here's a link:
http://www.lifelinebatteries.com/marine.asp
I would be interested in using the smallest, the GPL-U1T. It only weighs
24lbs, puts out 12V, 33Ah, and has 325 cranking amps at 68 deg F. If I used
34 of these to get 408V, I would be able to get the max hp and torque out of
the Siemens motor, and my pack would only weigh 816 lbs.
I have never built an EV before... how do these numbers sound as far as pack
voltage and pack weight? I know the amp hours are small, but I thought the
power output of the pack would compensate.
Has anyone ever used the Lifeline batteries before?
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There is. It is definition of R_int (all the conditions)
is unclear. What do you think internal resistance is?
If it is delta_U/delta_I, define:
-On delta raise or fall (e.g. charge or discharge R_int)?
-At what SOC?
-At what currents?
-At what delta U?
-At what temp?
- on DC or AC?
-if on AC, at what frequency?
(All these inter-related and of course, non-linear).
Once you know, then, the measurement itself is easy.
But as soon as someone else does it at different conditions,
results are not directly comparable.
Victor
Don Cameron wrote:
Is there an "easy" way to measure a battery's internal resistance? I am
measuring the voltage drop with a variety of loads, but I cannot get a
"definitive" answer.
thanks
Don
See the New Beetle EV Conversion Web Site at www.cameronsoftware.com/ev/
<outbind://65/www.cameronsoftware.com/ev/>
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Lead Acid batteries are lead acid batteries and no matter what you have for
a controller and motor setup 816 pounds of lead acid batteris are not going
to give you all that much range. If you are looking for something for a
very short commute this will work fine. I think you are looking at a 20 -
30 mile max range. Of course, I have no idea of what kind of car you are
talking about putting this into. The most popular small AGM batteries on
this list seem to be Hawkers.
From: Mike Barber <[EMAIL PROTECTED]>
Reply-To: [EMAIL PROTECTED]
To: [EMAIL PROTECTED]
Subject: Lifeline batteries
Date: Fri, 12 Nov 2004 12:22:31 -0800 (PST)
I've been researching what it would take to build an AC EV. So far I have
settled on using one of the Siemens automotive motors (hopefully able to
find a surplus one on ebay from Ford's EV ranger project). The problem was
that to get the rated max torque and hp from these motors, you would need
around 350V. I didn't want to have 2000lbs of batteries, so I had a
dilemma.
I think that I found a solution in Lifeline's marine deep cycle AGM
batteries. Here's a link:
http://www.lifelinebatteries.com/marine.asp
I would be interested in using the smallest, the GPL-U1T. It only weighs
24lbs, puts out 12V, 33Ah, and has 325 cranking amps at 68 deg F. If I
used 34 of these to get 408V, I would be able to get the max hp and torque
out of the Siemens motor, and my pack would only weigh 816 lbs.
I have never built an EV before... how do these numbers sound as far as
pack voltage and pack weight? I know the amp hours are small, but I
thought the power output of the pack would compensate.
Has anyone ever used the Lifeline batteries before?
---------------------------------
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Check out the new Yahoo! Front Page. www.yahoo.com
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Christopher Zach [mailto:[EMAIL PROTECTED] wrote:
> Voltage sag might be a question with that many floodeds; part of the
> reason high voltage EV's like AGMs.
>
> 24lbs for 33Ah is not too farm from my Genesis 26ah batteries (21lbs,
> 26ah 10hr rated).
The Concorde Lifelines *are* AGMs. They will not be happy with the
sorts of extreme rate discharge that the Hawkers can handle, but you pay
dearly for that in the Hawkers and if the application doesn't require
such high currents then the Concordes are worth considering.
I think the GPL-U1 is a bit small; I would look at least one model up
the ladder (and a few models up if you want any real range with the
truck; don't count on using more than 50% of any AGMs rated capacity on
a regular basis if you want reasonable cycle life).
We ran a pair of Lifeline GPL-1240 (I think; they renamed the models
shortly after we got our batteries) in our Electrathon. These are/were
slightly larger than the U1's at about 31lbs each and 40Ah. They
happily delivered the peak 275A our controller would allow us to draw,
and delivered respectable capacity. I can't comment on longevity as
racing involves a fair bit of abuse (charge & run the batteries hot,
discharge them totally flat, etc.).
Cheers,
Roger.
PS: Don: no, Concordes are not rebranded from another manufacturer.
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