[RE-wrenches] Air conditioning for batteries in high temperature climate

Fri Apr 22 12:13:21 PDT 2011

Hi Roy,

Hi temperatures will hit the battery capacity but 
will the battery efficiency be that much 
affected?  If the battery capacity is inadequate 
then you need to compare the aircon running cost 
to the cost of buying a 10% larger battery. 
Don't you?

Cheers

Hugh

>Bob is correct, I do have an off grid client 
>that uses an AC unit to keep the batteries cool.
>Although we're not in a high temp climate, it 
>does get into the 80's and low 90's here
>in the summer.
>
>By my calculations, he was losing an 'average' 
>of 10% storage capacity during the 5 month
>period from late spring to early fall. In July 
>and August it was closer to 18%, but for 
>calculation
>purposes, 10% is close enough. His bank capacity 
>is 4800AH @ 48 VDC. That's 230,400 watt hours
>and 10% of that rounds out to 23,000 watt hours lost to heat.
>
>I showed up one day to check something in the 
>power shed and was dismayed to see a window
>AC unit installed there. An interesting customer 
>discussion ensued and I had to admit he was
>correct in his calculations.
>
>The Energy Star rated AC unit consumes no more 
>than 3,000 watt hours per day, even in the
>highest heat. Essentially, he's 'spending" 3 
>kilowatt hours to 'buy back' 20 kilowatt hours of
>storage. He got me on that one!
>
>That reasoning didn't work on the 6 other AC 
>units that appeared on his house the following
>week. But that's another story altogether!
>Roy Butler
>NABCEP Certified Solar PV Installer®
>NYSERDA eligible PV & wind installer
>PA Sunshine Program Approved PV Installer
>Four Winds Renewable Energy, LLC
>8902 Route 46
>Arkport, NY 14807
>607-324-9747
>
><http://www.four-winds-energy.com>www.four-winds-energy.com
>
>Although no trees were killed in the sending of this message,
>a large number of electrons were terribly inconvenienced.
>
>                
>
>On 4/22/2011 7:40 AM, bob ellison wrote:
>
>>I believe Roy has a customer with a huge 
>>battery bank that air conditioned the battery 
>>room. He ran the numbers and the air 
>>conditioning actually made sense.
>>
>>
>>
>>Bob Ellison
>>
>>
>>
>>From: 
>><mailto:re-wrenches-bounces at lists.re-wrenches.org>re-wrenches-bounces at lists.re-wrenches.org 
>>[<mailto:re-wrenches-bounces at lists.re-wrenches.org>mailto:re-wrenches-bounces at lists.re-wrenches.org] 
>>On Behalf Of R Ray Walters
>>Sent: Thursday, April 21, 2011 4:50 PM
>>To: RE-wrenches
>>Subject: Re: [RE-wrenches] Air conditioning for 
>>batteies in high temperature climate
>>
>>
>>
>>Are you using temperature compensation? It lowers the voltage when its hot.
>>
>>Also, have you considered setting the batteries 
>>in a below ground vault? I've had good luck 
>>with in floor battery boxes.
>>
>>Finally, AGMs and L16s just don't last very 
>>long anyway. AGMs maybe 3 years, and L16s I've 
>>seen die in under 5 years and we get to 15 
>>below zero.
>>
>>My suggestion: temp comp, ground vault, HUP or equivalent cycle life.
>>
>>
>>
>>R. Walters
>>
>><mailto:ray at solarray.com>ray at solarray.com
>>
>>Solar Engineer
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>On Apr 21, 2011, at 1:22 PM, Starlight Solar, Larry Crutcher wrote:
>>
>>
>>
>>Hello Battery Wrenches,
>>
>>
>>
>>Over the years I have had several battery banks 
>>in Baja and Sonora Mexico fail in just 36 to 48 
>>months. These have been L16 or 8D AGM or 
>>flooded banks, 24 and 48 volt systems. The 
>>charging systems are working properly and 
>>programmed to manufacturer recommended set 
>>points and discharges are rarely over 30% DoD. 
>> Some batteries are only used on weekends, some 
>>are discharged daily.  I believe what is 
>>affecting the short life is the high 
>>temperature they live in for 5 months each 
>>year. Temps. can hit 115 F in vented battery 
>>rooms. I have been thinking about a small air 
>>conditioner and insulated battery box to keep 
>>the battery at no more than 80 F. There are 
>>some portable units that draw about 600 watts 
>>and the run time would be very little with a 
>>highly insulated enclosure. There is ample 
>>power to do this on the home I am changing 
>>batteries in now. Has anyone done this and 
>>gained longer battery life?
>>
>>
>>
>>Best Regards,
>>
>>Larry Crutcher
>><http://www.starlightsolar.com/>Starlight Solar Power Systems
>>
>>powered by STARLIGHT
>>
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-- 
Hugh Piggott

Scoraig
http://www.scoraigwind.co.uk
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