Re: [RE-wrenches] For Big Bank Off Grid System Connoisseurs

[Jeff Oldham]

I use a non-contact IR thermometer and tag the electrolyte.


>From the Solar, Wind and Hydro powered office of Jeff Oldham/Regenerative 
>SOLutions

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Re: [RE-wrenches] For Big Bank Off Grid System Connoisseurs

[Howie Michaelson]

Jeff Oldham  wrote:

>I have several 10 Outback inverter stacks in o-t-g applications and I use 66kW 
>Prime Power gensets for charging. It is common for me to see a total of 25kW 
>of charging w/low battery V although 18kW is about the average. I feel if the 
>loads dictate 36kW of inverter power and I can charge at 25kW then supporting 
>charging and loads could be 60kW plus. Most of these are in tropical 
>environments and controlling battery cell temps has been my biggest challenge 
>as I try to balance minimized run time/fuel consumption via robust charge 
>rates and keeping cell temps below 105 F. This is not easy with diurnal temps 
>about 80F. Generous battery can spacing and big time ventilation is mandatory 
>in hot climes. 
>
>
>>From the Solar, Wind and Hydro powered office of Jeff Oldham/Regenerative 
>>SOLutions
>
>Chemo & White Blood Cells
>A Low WBC Count Can Increase Your Risk of Infection. Learn More.
>http://thirdpartyoffers.juno.com/TGL3131/4c223aee349d54b622fst04vuc
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Re: [RE-wrenches] For Big Bank Off Grid System Connoisseurs

[Mark Frye]

What is the best way to measure cell temp in the situation you describe?
 
Mark Frye 
Berkeley Solar Electric Systems 
303 Redbud Way 
Nevada City,  CA 95959 
(530) 401-8024 
 <http://www.berkeleysolar.com/> www.berkeleysolar.com  
 

  _  

From: re-wrenches-boun...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Jeff Oldham
Sent: Wednesday, June 23, 2010 9:47 AM
To: re-wrenches@lists.re-wrenches.org
Subject: Re: [RE-wrenches] For Big Bank Off Grid System Connoisseurs


I have several 10 Outback inverter stacks in o-t-g applications and I use
66kW Prime Power gensets for charging. It is common for me to see a total of
25kW of charging w/low battery V although 18kW is about the average. I feel
if the loads dictate 36kW of inverter power and I can charge at 25kW then
supporting charging and loads could be 60kW plus. Most of these are in
tropical environments and controlling battery cell temps has been my biggest
challenge as I try to balance minimized run time/fuel consumption via robust
charge rates and keeping cell temps below 105 F. This is not easy with
diurnal temps about 80F. Generous battery can spacing and big time
ventilation is mandatory in hot climes. 


>From the Solar, Wind and Hydro powered office of Jeff Oldham/Regenerative
SOLutions 


 <http://thirdpartyoffers.juno.com/TGL3132/4c223aee349d54b622fst04vuc> Chemo
& White Blood Cells
A Low WBC Count Can Increase Your Risk of Infection. Learn More.
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Re: [RE-wrenches] For Big Bank Off Grid System Connoisseurs

[bob]

Here is what I am thinking of doing: I want to remove the string of
batteries with the bad cell completely from the system. That gives me an
increase in my bulk charge current for the remaining strings and reduces the
number of parallel strings. I also want 4 times a year to adjust the charge
parameters to match the seasonal condition including tacking on as much
absorption time as feasible.

So what to do with all those extra batteries? Can I cut them all out into
the individual cells, drain the acid and keep them in storage, available to
replace bad cells in the future?

Mark,

Do not remove and drain the cells, they will be ruined soon if you do. 

How about replacing the bad cell with a new one? This is done all the time
on the forklift industry. It will extend the life of the bank and keep the
battery size the same as originally planned.

 

I would move the absorb setting to as long as you can on the generator and
on the charge controllers also.

I assume these cells are welded together with lead straps. Drill them off
and weld In another cell. All done, back to normal.

 

Bob Ellison 

 

 

From: re-wrenches-boun...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Mark Frye
Sent: Monday, June 21, 2010 11:21 PM
To: 'RE-wrenches'
Subject: [RE-wrenches] For Big Bank Off Grid System Connoisseurs

 

Here are details of a system I am working with: 

2 hours south of Sacramento CA and west into the coast range for 5 miles and
30 minutes on a rough dirt road is an improvement. The improvement consists
of a large main house, 2 separate guest cabins, and a four car garage, all
built out of logs from British Columbia. Out back and up the hill is a power
house.  There is a well with bad water and a satellite telephone, no PG&E.
Most of the time no one is around, but a few times a year, folks show up and
have a party.

This off-grid power system consists of 16 - Enersys 1690 AH @ 20 hour HUP
12V forklift batteries. The batteries are arranged in 4 strings of 4
batteries each.

There are 10 - Outback VFX3648 inverters in a 2 phase stack. 

There is a Kohler REGZ 30 KVA propane powered generator. 

Also included is about 5 KW worth of Astropower 120 modules plugged into 2
MX60s. 

A Trimetric TM-2020 watches the charge flowing in and out of the battery
bank. 

The system has run without interruption or major problem for 6 years.
However, recently we have had our first major service on the generator, our
first smoked inverter, and we have a dead cell in one of the batteries.

Besides the occasionally high demand use events, the stand by conditions run
along two seasonal veins: In summer the main demand besides the usual
refrigerator and alarm system is pumping and treating irrigation water; In
the winter heating systems run to keep the buildings warm.

The contribution of the PV is secondary. On a recent visit the 2 MX's
generated about 30KWH of energy in a day. However, this significant
contribution to the system is generally not sufficient to completely offset
the summer standby loads and the generator will run according to it's AGS
setting about once every 2 - 3 weeks.  In the winter the generator runs more
often.

I have the AGS running on Volt Start and it appears that the generator will
run after somewhere between 2000 and 3000 Ah have been removed from the
bank. Once started the charge settings are bulk to 60V, absorb for 12
minutes and shut-off. In the winter the chargers can run at almost their
full power and deliver about 360 A during the bulk phase. In the summer the
chargers fold back significantly due to heat in the power house. This
folded-back charge rate is what has dictated the charge regime. Not wanting
to run the generator at reduce capacity for extended lengths of time means
getting the voltage up through the bulk phase as best as possible in the
summer and then bailing on the absorption phase. This has been the
one-size-fits-all setting that has been running all year round for 6 years.

Recently I checked the specific gravity of the batteries at the end of the
normal charge cycle and got 1260 in most cells. Interestingly enough I then
put in an additional 1200 Ah and the sp didn't budge.

My sense is that the bank, on average, has been getting charging up to about
80-85% of full and then discharging to about 50-55% of full.

So there you have it. Perhaps a lamentable state of affairs, but the state
of affairs none the less. 

I know there are many many possibilities for this system. The owner would
prefer to manage on-going maintenance costs as opposed to making significant
capital expenditures on major system reconfigurations.

Here is what I am thinking of doing: I want to remove the string of
batteries with the bad cell completely from the system. That gives me an
increase in my bulk charge current for the remaining strings and reduces the
number of parallel strings. I also want 4 times a year to adjust the charge
par

Re: [RE-wrenches] For Big Bank Off Grid System Connoisseurs

[Jeff Oldham]

I have several 10 Outback inverter stacks in o-t-g applications and I use 66kW 
Prime Power gensets for charging. It is common for me to see a total of 25kW of 
charging w/low battery V although 18kW is about the average. I feel if the 
loads dictate 36kW of inverter power and I can charge at 25kW then supporting 
charging and loads could be 60kW plus. Most of these are in tropical 
environments and controlling battery cell temps has been my biggest challenge 
as I try to balance minimized run time/fuel consumption via robust charge rates 
and keeping cell temps below 105 F. This is not easy with diurnal temps about 
80F. Generous battery can spacing and big time ventilation is mandatory in hot 
climes. 


>From the Solar, Wind and Hydro powered office of Jeff Oldham/Regenerative 
>SOLutions

Chemo & White Blood Cells
A Low WBC Count Can Increase Your Risk of Infection. Learn More.
http://thirdpartyoffers.juno.com/TGL3131/4c223aee349d54b622fst04vuc___
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Re: [RE-wrenches] For Big Bank Off Grid System Connoisseurs

[Bob-O Schultze]

One set of batteries in a series string is best. two paralleled strings are OK, 
three are marginal, four or more is just a bad idea and it's nearly impossible 
to get them to play nice together for long.
Good Luck, bob-O

On Jun 22, 2010, at 5:15 PM, Mark Frye wrote:

Thanks Phil,
 
I really appreciate all the input I am getting.
 
As I mentioned, these are not the Solar One batteries, they are forklift 
batteries, so I am not even going to talk to NWES.
 
I am working with the regional Enersys service center to have a guy out to cut 
and re-weld the interconnects after the cell is replaced. If they want to help 
me out because the battery is still within the 5/2 forklift warranty period, 
that will be fine.
 
Everything you say makes sense.  The owner is on-board with spending more time 
and effort in order to care for the batteries and I am working up a plan to do 
that.
 
At this point it looks something like:
 
- Replace the bad cell and continue with the 4 string system size
- Give the bank a full EQ charge. I like your set points of 62-64 V for 3 to 4 
hours (just don't get the cells too hot). I would really like to see all the 
cells up to 1.280 for once. I can break the bank down to it's individual 
strings to do this, in order to give it a bit more punch
- Review and adjust the charge settings 2 to 4 times a year to optimize for 
seasonal changes in ambient temperatures and load profiles. This might include 
adjusting the volt start settings to insure that the generator is running more 
often (every 7-10 days sounds good to me); extending the absorb time as much as 
possible (staying above 50% load on the generator).
- Giving an EQ charge as above once every 4 to 8 weeks.
 
I imagine that in this way they will muddle along fine for quite sometime. When 
a major capital component needs to be replaced they can make the best choice at 
that time.
 
I like a lot of the other ideas that have come up such as more ventilation, 
both of the room and the inverters.
 
Please any more thoughts you may have.

Mark Frye 
Berkeley Solar Electric Systems 
303 Redbud Way 
Nevada City,  CA 95959 
(530) 401-8024 
www.berkeleysolar.com 
 

From: re-wrenches-boun...@lists.re-wrenches.org 
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Phil 
Undercuffler
Sent: Tuesday, June 22, 2010 4:29 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] For Big Bank Off Grid System Connoisseurs

I'm still not clear on why everyone thinks that this is a failure which should 
be covered under warranty.  If Rob or Jean want to give a free cell, then 
that's above and beyond -- but I don't think we should be blaming the battery 
in this case. 

Let's explore the situation.  We've got 6760 AH of battery storage, in four 
parallel strings.  Four strings in parallel would not be my recommendations, 
but let's leave that aside for now.  The solar, if putting out full rated 
wattage with no degradation due to heat, off-axis, shading, soiling, or any 
other loss will put out a whopping 100 amps, for a mind boggling C/67.  Add 
normal derates, and we're down to a C/80 charge rate, and we haven't even 
accounted for daytime loads.  The solar is there for show, and to make the 
owners feel green.

So how about the generator charging?  We have 10 Outback inverters -- that 
should be enough, right?  Well, 10x45A each gives us a C/15 charge rate, which 
should be OK.  But is the generator large enough?  That's a lot of inverters to 
drive, this load is pretty reactive, and we've not any information about the 
background AC loads except that they're probably pretty large.  Wait, the 
generator is only 30kVA, which is only good for 24kVA of continuous resistive 
load (30*.08).  What's the altitude of the installation -- if it's higher than 
1,000 feet the generator should be further derated.  No inverter is as 
efficient at charging as it is at inverting, so of that 24kVA of available 
generator capacity, only 19kVA is likely to make it to the batteries -- that's 
a likely C/21 charge rate if there were no AC loads, but there are, so it's 
likely to be lower.

And when do the batteries get charged?  Not every day -- the solar can barely 
keep up with the self discharge.  The generator runs every 2 - 3 weeks, so the 
batteries are in a state of near constant discharge for 14 - 21 days on 
average.  When they get so low they hit the AGS floor, the generator kicks in.  
However, just as the battery voltage climbs to the beginning of the absorption 
state, the generator is shut off.  

These batteries haven't been full in over six years.  They haven't received a 
proper charge in over six years, either.  I'm surprised they've lasted as long 
as they have.  Let me guess the last time they were equalized -- really 
equalized, not just "I hit the button and ran the generator until I got tired 
of the noise" equalized -- as in 

Re: [RE-wrenches] For Big Bank Off Grid System Connoisseurs

[Mark Frye]

Thanks Phil,
 
I really appreciate all the input I am getting.
 
As I mentioned, these are not the Solar One batteries, they are forklift
batteries, so I am not even going to talk to NWES.
 
I am working with the regional Enersys service center to have a guy out to
cut and re-weld the interconnects after the cell is replaced. If they want
to help me out because the battery is still within the 5/2 forklift warranty
period, that will be fine.
 
Everything you say makes sense.  The owner is on-board with spending more
time and effort in order to care for the batteries and I am working up a
plan to do that.
 
At this point it looks something like:
 
- Replace the bad cell and continue with the 4 string system size
- Give the bank a full EQ charge. I like your set points of 62-64 V for 3 to
4 hours (just don't get the cells too hot). I would really like to see all
the cells up to 1.280 for once. I can break the bank down to it's individual
strings to do this, in order to give it a bit more punch
- Review and adjust the charge settings 2 to 4 times a year to optimize for
seasonal changes in ambient temperatures and load profiles. This might
include adjusting the volt start settings to insure that the generator is
running more often (every 7-10 days sounds good to me); extending the absorb
time as much as possible (staying above 50% load on the generator).
- Giving an EQ charge as above once every 4 to 8 weeks.
 
I imagine that in this way they will muddle along fine for quite sometime.
When a major capital component needs to be replaced they can make the best
choice at that time.
 
I like a lot of the other ideas that have come up such as more ventilation,
both of the room and the inverters.
 
Please any more thoughts you may have.

Mark Frye 
Berkeley Solar Electric Systems 
303 Redbud Way 
Nevada City,  CA 95959 
(530) 401-8024 
 <http://www.berkeleysolar.com/> www.berkeleysolar.com  
 

  _  

From: re-wrenches-boun...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Phil
Undercuffler
Sent: Tuesday, June 22, 2010 4:29 PM
To: RE-wrenches
Subject: Re: [RE-wrenches] For Big Bank Off Grid System Connoisseurs


I'm still not clear on why everyone thinks that this is a failure which
should be covered under warranty.  If Rob or Jean want to give a free cell,
then that's above and beyond -- but I don't think we should be blaming the
battery in this case.  

Let's explore the situation.  We've got 6760 AH of battery storage, in four
parallel strings.  Four strings in parallel would not be my recommendations,
but let's leave that aside for now.  The solar, if putting out full rated
wattage with no degradation due to heat, off-axis, shading, soiling, or any
other loss will put out a whopping 100 amps, for a mind boggling C/67.  Add
normal derates, and we're down to a C/80 charge rate, and we haven't even
accounted for daytime loads.  The solar is there for show, and to make the
owners feel green.

So how about the generator charging?  We have 10 Outback inverters -- that
should be enough, right?  Well, 10x45A each gives us a C/15 charge rate,
which should be OK.  But is the generator large enough?  That's a lot of
inverters to drive, this load is pretty reactive, and we've not any
information about the background AC loads except that they're probably
pretty large.  Wait, the generator is only 30kVA, which is only good for
24kVA of continuous resistive load (30*.08).  What's the altitude of the
installation -- if it's higher than 1,000 feet the generator should be
further derated.  No inverter is as efficient at charging as it is at
inverting, so of that 24kVA of available generator capacity, only 19kVA is
likely to make it to the batteries -- that's a likely C/21 charge rate if
there were no AC loads, but there are, so it's likely to be lower.

And when do the batteries get charged?  Not every day -- the solar can
barely keep up with the self discharge.  The generator runs every 2 - 3
weeks, so the batteries are in a state of near constant discharge for 14 -
21 days on average.  When they get so low they hit the AGS floor, the
generator kicks in.  However, just as the battery voltage climbs to the
beginning of the absorption state, the generator is shut off.  

These batteries haven't been full in over six years.  They haven't received
a proper charge in over six years, either.  I'm surprised they've lasted as
long as they have.  Let me guess the last time they were equalized -- really
equalized, not just "I hit the button and ran the generator until I got
tired of the noise" equalized -- as in charge until the voltage rises up to
62-64 volts for 3 or 4 hours, and the specific gravity on each and every
cell hits 1.265.  Was the bank commissioned with an EQ upon installation?  

I think that one of the best things that can be done to serve these clients
(other

Re: [RE-wrenches] For Big Bank Off Grid System Connoisseurs

[Phil Undercuffler]

I'm still not clear on why everyone thinks that this is a failure which
should be covered under warranty.  If Rob or Jean want to give a free cell,
then that's above and beyond -- but I don't think we should be blaming the
battery in this case.

Let's explore the situation.  We've got 6760 AH of battery storage, in four
parallel strings.  Four strings in parallel would not be my recommendations,
but let's leave that aside for now.  The solar, if putting out full rated
wattage with no degradation due to heat, off-axis, shading, soiling, or any
other loss will put out a whopping 100 amps, for a mind boggling C/67.  Add
normal derates, and we're down to a C/80 charge rate, and we haven't even
accounted for daytime loads.  The solar is there for show, and to make the
owners feel green.

So how about the generator charging?  We have 10 Outback inverters -- that
should be enough, right?  Well, 10x45A each gives us a C/15 charge rate,
which should be OK.  But is the generator large enough?  That's a lot of
inverters to drive, this load is pretty reactive, and we've not any
information about the background AC loads except that they're probably
pretty large.  Wait, the generator is only 30kVA, which is only good for
24kVA of continuous resistive load (30*.08).  What's the altitude of the
installation -- if it's higher than 1,000 feet the generator should be
further derated.  No inverter is as efficient at charging as it is at
inverting, so of that 24kVA of available generator capacity, only 19kVA is
likely to make it to the batteries -- that's a likely C/21 charge rate if
there were no AC loads, but there are, so it's likely to be lower.

And when do the batteries get charged?  Not every day -- the solar can
barely keep up with the self discharge.  The generator runs every 2 - 3
weeks, so the batteries are *in a state of near constant discharge for 14 -
21 days on average*.  When they get so low they hit the AGS floor, the
generator kicks in.  However, just as the battery voltage climbs to the
beginning of the absorption state, the generator is shut off.

These batteries haven't been full in over six years.  They haven't received
a proper charge in over six years, either.  I'm surprised they've lasted as
long as they have.  Let me guess the last time they were equalized -- really
equalized, not just "I hit the button and ran the generator until I got
tired of the noise" equalized -- as in charge until the voltage rises up to
62-64 volts for 3 or 4 hours, and the specific gravity on each and every
cell hits 1.265.  Was the bank commissioned with an EQ upon installation?

I think that one of the best things that can be done to serve these clients
(other than recommend a huge investment in efficiency) is to decrease the
time between generator charges by 50-75%. You want to get it to the point
where the generator is cycling on at least every 7-10 days.  In addition,
you really want to extend the absorption time -- 12 minutes is just not
enough to do anything but tease.  The customer really needs a bigger
generator to drive this system, too.  Adding vent fans to the power room is
highly recommended -- you're dissipating something like 6,000 watts of heat
when you're running 10 inverters at full charge.  Power the vent fans off
the generator output, so they only come on when the system is charging.

When it's time to replace this bank of batteries, I'd recommend looking at
decreasing the size of the bank by 50%.  And investing more in efficiency,
of course.

Hope this helps,

Phil Undercuffler


On Tue, Jun 22, 2010 at 11:14 AM, Jeff Oldham  wrote:

> Those HUP batteries are still under warranty and you very well may have a
> free cell waiting for you, give Rob or Jean a call at NWES and run it past
> them. They offer 1st rate CS and should take good care of you. You won't get
> much for used batteries so I would be inclined to keep them in service even
> though 4 strings in parallel is not ideal. I've had reasonable luck with 4
> strings paralleled by getting my battery/inverter cables all over the bank,
> at the least put 1/2 of your inverters across 2 strings and the other 1/2 on
> the remaining 2 strings (still parallel all 4 strings).
>
> You never mentioned an EQ cycle either, with that limited Absorption time
> it should happen at least every 6 weeks.
>
>
> From the Solar, Wind and Hydro powered office of Jeff Oldham/Regenerative
> SOLutions
>
> 
> *TODAY: iPads for $23.78?*
> Report: Apple iPads are being auctioned for an incredible 83% off!
> 
> ConsumerProductsDigest.com
> ___
> List sponsored by Home Power magazine
>
> List Address: RE-wrenches@lists.re-wrenches.org
>
> Options & settings:
> http://lists.re-wrenches.org/options.cgi/re-wrenches-re-wrenches.org
>
> List-Arch

Re: [RE-wrenches] For Big Bank Off Grid System Connoisseurs

[Mark Frye]

In this case the 4 individual banks are connected to a common buss.  All
four buss-to-bank cable sets are of identical lenght.
 
Mark Frye 
Berkeley Solar Electric Systems 
303 Redbud Way 
Nevada City,  CA 95959 
(530) 401-8024 
 <http://www.berkeleysolar.com/> www.berkeleysolar.com  
 

  _  

From: re-wrenches-boun...@lists.re-wrenches.org
[mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Tom Elliot
Sent: Tuesday, June 22, 2010 10:28 AM
To: RE-wrenches
Subject: Re: [RE-wrenches] For Big Bank Off Grid System Connoisseurs


If you have to parallel 4 banks do it through a buss bar, not by
interconnecting cells.  A few extra cables is a small price to pay for the
added stability and easier maintenance.
 
Tom
 

From: Jeff Oldham <mailto:starpowe...@juno.com>  
Sent: Tuesday, June 22, 2010 7:14 AM
To: re-wrenches@lists.re-wrenches.org 
Subject: Re: [RE-wrenches] For Big Bank Off Grid System Connoisseurs

Those HUP batteries are still under warranty and you very well may have a
free cell waiting for you, give Rob or Jean a call at NWES and run it past
them. They offer 1st rate CS and should take good care of you. You won't get
much for used batteries so I would be inclined to keep them in service even
though 4 strings in parallel is not ideal. I've had reasonable luck with 4
strings paralleled by getting my battery/inverter cables all over the bank,
at the least put 1/2 of your inverters across 2 strings and the other 1/2 on
the remaining 2 strings (still parallel all 4 strings).

You never mentioned an EQ cycle either, with that limited Absorption time it
should happen at least every 6 weeks. 


>From the Solar, Wind and Hydro powered office of Jeff Oldham/Regenerative
SOLutions 


 <http://thirdpartyoffers.juno.com/TGL3132/4c20efb95654048a554st06vuc>
TODAY: iPads for $23.78?
Report: Apple iPads are being auctioned for an incredible 83% off!
ConsumerProductsDigest.com
<http://thirdpartyoffers.juno.com/TGL3132/4c20efb95654048a554st06vuc>  


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No virus found in this incoming message.
Checked by AVG - www.avg.com 
Version: 9.0.829 / Virus Database: 271.1.1/2954 - Release Date: 06/21/10
08:36:00

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Re: [RE-wrenches] For Big Bank Off Grid System Connoisseurs

[Tom Elliot]

If you have to parallel 4 banks do it through a buss bar, not by 
interconnecting cells.  A few extra cables is a small price to pay for the 
added stability and easier maintenance.

Tom



From: Jeff Oldham 
Sent: Tuesday, June 22, 2010 7:14 AM
To: re-wrenches@lists.re-wrenches.org 
Subject: Re: [RE-wrenches] For Big Bank Off Grid System Connoisseurs


Those HUP batteries are still under warranty and you very well may have a free 
cell waiting for you, give Rob or Jean a call at NWES and run it past them. 
They offer 1st rate CS and should take good care of you. You won't get much for 
used batteries so I would be inclined to keep them in service even though 4 
strings in parallel is not ideal. I've had reasonable luck with 4 strings 
paralleled by getting my battery/inverter cables all over the bank, at the 
least put 1/2 of your inverters across 2 strings and the other 1/2 on the 
remaining 2 strings (still parallel all 4 strings).

You never mentioned an EQ cycle either, with that limited Absorption time it 
should happen at least every 6 weeks. 


>From the Solar, Wind and Hydro powered office of Jeff Oldham/Regenerative 
>SOLutions 


TODAY: iPads for $23.78?
Report: Apple iPads are being auctioned for an incredible 83% off!
ConsumerProductsDigest.com 





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No virus found in this incoming message.
Checked by AVG - www.avg.com 
Version: 9.0.829 / Virus Database: 271.1.1/2954 - Release Date: 06/21/10 
08:36:00
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Re: [RE-wrenches] For Big Bank Off Grid System Connoisseurs

[Jeff Oldham]

Those HUP batteries are still under warranty and you very well may have a free 
cell waiting for you, give Rob or Jean a call at NWES and run it past them. 
They offer 1st rate CS and should take good care of you. You won't get much for 
used batteries so I would be inclined to keep them in service even though 4 
strings in parallel is not ideal. I've had reasonable luck with 4 strings 
paralleled by getting my battery/inverter cables all over the bank, at the 
least put 1/2 of your inverters across 2 strings and the other 1/2 on the 
remaining 2 strings (still parallel all 4 strings).

You never mentioned an EQ cycle either, with that limited Absorption time it 
should happen at least every 6 weeks. 


>From the Solar, Wind and Hydro powered office of Jeff Oldham/Regenerative 
>SOLutions

TODAY: iPads for $23.78?
Report: Apple iPads are being auctioned for an incredible 83% off!
http://thirdpartyoffers.juno.com/TGL3131/4c20efb95654048a554st06vuc___
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Re: [RE-wrenches] For Big Bank Off Grid System Connoisseurs

[Nick Soleil]

It sounds like your power room is getting too hot in the summer months.  Adding 
a solar attic fan and/or more ventilation may really help keep the batteries 
and equipment healthier.  I have seen batteries destroyed by loosing too much 
water during summer charging.  I would try to repair or replace the bad cell 
for now.

 Nick Soleil
Project Manager
Advanced Alternative Energy Solutions, LLC
PO Box 657
Petaluma, CA 94953
Cell:   707-321-2937
Office: 707-789-9537
Fax:707-769-9037





From: Mark Frye 
To: RE-wrenches 
Sent: Mon, June 21, 2010 8:21:06 PM
Subject: [RE-wrenches] For Big Bank Off Grid System Connoisseurs

 For Big Bank Off Grid System Connoisseurs 
Here are details of a system I am working with: 
2 hours south of Sacramento CA and west into the coast range for 5 miles and 30 
minutes on a rough dirt road is an improvement. The improvement consists of a 
large main house, 2 separate guest cabins, and a four car garage, all built out 
of logs from British Columbia. Out back and up the hill is a power house.  
There is a well with bad water and a satellite telephone, no PG&E. Most of the 
time no one is around, but a few times a year, folks show up and have a party.
This off-grid power system consists of 16 - Enersys 1690 AH @ 20 hour HUP 12V 
forklift batteries. The batteries are arranged in 4 strings of 4 batteries each.
There are 10 - Outback VFX3648 inverters in a 2 phase stack. 
There is a Kohler REGZ 30 KVA propane powered generator. 
Also included is about 5 KW worth of Astropower 120 modules plugged into 2 
MX60s. 
A Trimetric TM-2020 watches the charge flowing in and out of the battery bank. 
The system has run without interruption or major problem for 6 years. However, 
recently we have had our first major service on the generator, our first smoked 
inverter, and we have a dead cell in one of the batteries.
Besides the occasionally high demand use events, the stand by conditions run 
along two seasonal veins: In summer the main demand besides the usual 
refrigerator and alarm system is pumping and treating irrigation water; In the 
winter heating systems run to keep the buildings warm.
The contribution of the PV is secondary. On a recent visit the 2 MX's generated 
about 30KWH of energy in a day. However, this significant contribution to the 
system is generally not sufficient to completely offset the summer standby 
loads and the generator will run according to it's AGS setting about once every 
2 - 3 weeks.  In the winter the generator runs more often.
I have the AGS running on Volt Start and it appears that the generator will run 
after somewhere between 2000 and 3000 Ah have been removed from the bank. Once 
started the charge settings are bulk to 60V, absorb for 12 minutes and 
shut-off. In the winter the chargers can run at almost their full power and 
deliver about 360 A during the bulk phase. In the summer the chargers fold back 
significantly due to heat in the power house. This folded-back charge rate is 
what has dictated the charge regime. Not wanting to run the generator at reduce 
capacity for extended lengths of time means getting the voltage up through the 
bulk phase as best as possible in the summer and then bailing on the absorption 
phase. This has been the one-size-fits-all setting that has been running all 
year round for 6 years.
Recently I checked the specific gravity of the batteries at the end of the 
normal charge cycle and got 1260 in most cells. Interestingly enough I then put 
in an additional 1200 Ah and the sp didn't budge.
My sense is that the bank, on average, has been getting charging up to about 
80-85% of full and then discharging to about 50-55% of full.
So there you have it. Perhaps a lamentable state of affairs, but the state of 
affairs none the less. 
I know there are many many possibilities for this system. The owner would 
prefer to manage on-going maintenance costs as opposed to making significant 
capital expenditures on major system reconfigurations.
Here is what I am thinking of doing: I want to remove the string of batteries 
with the bad cell completely from the system. That gives me an increase in my 
bulk charge current for the remaining strings and reduces the number of 
parallel strings. I also want 4 times a year to adjust the charge parameters to 
match the seasonal condition including tacking on as much absorption time as 
feasible.
So what to do with all those extra batteries? Can I cut them all out into the 
individual cells, drain the acid and keep them in storage, available to replace 
bad cells in the future?
Any advice? 
  
Mark Frye 
Berkeley Solar Electric Systems 
303 Redbud Way 
Nevada City,  CA 95959 
(530) 401-8024 
www.berkeleysolar.com  


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[RE-wrenches] For Big Bank Off Grid System Connoisseurs

[Mark Frye]

Here are details of a system I am working with:

2 hours south of Sacramento CA and west into the coast range for 5 miles and
30 minutes on a rough dirt road is an improvement. The improvement consists
of a large main house, 2 separate guest cabins, and a four car garage, all
built out of logs from British Columbia. Out back and up the hill is a power
house.  There is a well with bad water and a satellite telephone, no PG&E.
Most of the time no one is around, but a few times a year, folks show up and
have a party.

This off-grid power system consists of 16 - Enersys 1690 AH @ 20 hour HUP
12V forklift batteries. The batteries are arranged in 4 strings of 4
batteries each.

There are 10 - Outback VFX3648 inverters in a 2 phase stack.

There is a Kohler REGZ 30 KVA propane powered generator.

Also included is about 5 KW worth of Astropower 120 modules plugged into 2
MX60s.

A Trimetric TM-2020 watches the charge flowing in and out of the battery
bank.

The system has run without interruption or major problem for 6 years.
However, recently we have had our first major service on the generator, our
first smoked inverter, and we have a dead cell in one of the batteries.

Besides the occasionally high demand use events, the stand by conditions run
along two seasonal veins: In summer the main demand besides the usual
refrigerator and alarm system is pumping and treating irrigation water; In
the winter heating systems run to keep the buildings warm.

The contribution of the PV is secondary. On a recent visit the 2 MX's
generated about 30KWH of energy in a day. However, this significant
contribution to the system is generally not sufficient to completely offset
the summer standby loads and the generator will run according to it's AGS
setting about once every 2 - 3 weeks.  In the winter the generator runs more
often.

I have the AGS running on Volt Start and it appears that the generator will
run after somewhere between 2000 and 3000 Ah have been removed from the
bank. Once started the charge settings are bulk to 60V, absorb for 12
minutes and shut-off. In the winter the chargers can run at almost their
full power and deliver about 360 A during the bulk phase. In the summer the
chargers fold back significantly due to heat in the power house. This
folded-back charge rate is what has dictated the charge regime. Not wanting
to run the generator at reduce capacity for extended lengths of time means
getting the voltage up through the bulk phase as best as possible in the
summer and then bailing on the absorption phase. This has been the
one-size-fits-all setting that has been running all year round for 6 years.

Recently I checked the specific gravity of the batteries at the end of the
normal charge cycle and got 1260 in most cells. Interestingly enough I then
put in an additional 1200 Ah and the sp didn't budge.

My sense is that the bank, on average, has been getting charging up to about
80-85% of full and then discharging to about 50-55% of full.

So there you have it. Perhaps a lamentable state of affairs, but the state
of affairs none the less.

I know there are many many possibilities for this system. The owner would
prefer to manage on-going maintenance costs as opposed to making significant
capital expenditures on major system reconfigurations.

Here is what I am thinking of doing: I want to remove the string of
batteries with the bad cell completely from the system. That gives me an
increase in my bulk charge current for the remaining strings and reduces the
number of parallel strings. I also want 4 times a year to adjust the charge
parameters to match the seasonal condition including tacking on as much
absorption time as feasible.

So what to do with all those extra batteries? Can I cut them all out into
the individual cells, drain the acid and keep them in storage, available to
replace bad cells in the future?

Any advice?
 
Mark Frye
Berkeley Solar Electric Systems
303 Redbud Way
Nevada City,  CA 95959
(530) 401-8024
www.berkeleysolar.com 

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