[RE-wrenches] Battery Freezing (was Trace...)

Kelly Larson solarwrench at asis.com
Thu Jan 13 11:57:14 PST 2011


> "Warning: those old DIY setups quickly become a can of worms, the  
> further you dig into them. Don't assume anything was done right."

...Including checking the polarity of every wire!  Who knows what the  
color meant to the last guy.

And don't just mess with a few things and leave it.  That customer is  
sure to have more problems and you were the last to touch it.  (God  
forbid if they have an electrical fire.)  Tell them it will take time  
to fix the mess.   Make yourself a wiring diagram following every  
wire.   This will take some customer investment, but result in a  
working system and happy customer.

Blessings,
Kelly

Kelly Larson
Box 104
Piercy, CA 95587
707-223-3209
Electrical Engineer
NABCEP Certified Solar PV Installer
ISPQ Master Trainer
CA C-10 # 868189
SolarKelly at asis.com

"I'd put my money on the sun and solar energy. What a source of  
power!  I hope we don't have to wait until oil and coal run out before  
we tackle that."   	~ Thomas Edison




On Dec 29, 2010, at 10:59 AM, R Ray Walters wrote:

> Jay;
>
> I've saved a few sets from freezing, different manufacturers' cases  
> are stronger than others. (ie, A Trojan T105 can take more stress  
> than something from Sam's Club.)
> FIrst I make sure they're less than 5 years old.
> Then, I warm them backup (portable propane heater, very well vented  
> area, no current flow in or out)
> 3rd, See if any are leaking
> 4th, Charge them with the caps off, monitoring voltage, current,  
> temperature, and bubbling action.
>
> Jesse;
>
> Your eyes and health are not worth risking to save those old things;  
> 12 years is a fairly respectable lifespan in a poorly setup system.
> I think to continue to work with those batteries is inviting danger  
> (everyone's recent explosion stories?)
> All those problems were caused by shorting plates, and other  
> malfunctions, usually only seen in old batteries.
>
> Batteries only freeze when completely abused. The inverter probably  
> was shutting off all the time from low voltage, and they had DC  
> loads dragging it down even lower.
> The recent string on battery temperature management should be  
> applied in this case too. I've seen poorly designed venting, freeze  
> batteries right next to it, while the batteries on the inside
> were warm.
>
> I agree with Allan's assessment: this set is toast, and considering  
> this is the worst time of year to not have a good battery set, I'd  
> take care of that lady, and get her into a fresh set, ASAP.
> This is also a chance to do some needed rewiring of the system.
> Warning: those old DIY setups quickly become a can of worms, the  
> further you dig into them. Don't assume anything was done right.
>
> R. Walters
> ray at solarray.com
> Solar Engineer
>
>
>
>
> On Dec 29, 2010, at 9:16 AM, jay peltz wrote:
>
>> I'd like to go back to the freezing battery part as I don't live in  
>> real freezing territory.
>>
>> How could they actually freeze and not destroy the housing,  
>> internal plate structure and in the end work at all?
>>
>> thanks,
>>
>> jay
>>
>>
>>
>>
>>
>>
>>> From: re-wrenches-bounces at lists.re-wrenches.org [mailto:re-wrenches-bounces at lists.re-wrenches.org 
>>> ] On Behalf Of Allan Sindelar
>>> Sent: Wednesday, December 29, 2010 10:41 AM
>>> To: dahlsolar at gmail.com; RE-wrenches
>>> Subject: Re: [RE-wrenches] Trace inverters undercharging batteries.
>>>
>>> Jesse,
>>> Don't waste your time on those batteries; they are all toast.  
>>> Don't replace them with the same; four strings is poor design.  
>>> Read the article about off-grid batteries in the current Home  
>>> Power, and then sell the customer a set of 12 (or 24; either one  
>>> string or two is OK) 2V industrial cells, such as HUPs from  
>>> Northwest Energy Storage or K-series Surrettes. Size unknown. The  
>>> existing full bank was 1400 A/hr if the cell cases had black  
>>> covers, 1600 A/hr if the tops are blue, to give you an idea.
>>>
>>> BP modules from 1998 would have most likely been 12V 75W or 85W,  
>>> meaning 900-1000 watts; too small an array for that size battery  
>>> bank if the home is used full-time; OK for a seasonal or weekend  
>>> cabin.
>>>
>>> Only with new batteries can you even tell what the inverters are  
>>> doing. My hunch is that the inverters aren't at fault. However,  
>>> given the poor quality of the original installation, they likely  
>>> are set to default setpoints, which can charge at a very high rate  
>>> (about 220A at 28.8V for two if the gennie is big enough) but  
>>> won't get batteries full (and can't equalize them), as the default  
>>> setpoints are too low. And I'll bet dollars to doughnuts the  
>>> default setpoints are in place, as the inverters have been shut  
>>> down sometime in the last 12 years, losing any original  
>>> programming settings.
>>>
>>> You might see about getting an experienced off-gridder in your  
>>> frozen region to work with you. Maybe Darryl could consult now,  
>>> then make one trip out to set up the system once the new batteries  
>>> are in. This was the classic late-90s system with a later charge  
>>> controller upgrade, but if you have never worked with this  
>>> equipment, you're likely to set it up for a repeat failure years  
>>> down the road.
>>>
>>> Just read Jamie's post - while his advice is spot on, of course,  
>>> you need to decide if it's worth your while. I'd be more inclined  
>>> to try his approach if the battery bank was three years old, not  
>>> 12. That's a huge amount of time spent, working with acid and an  
>>> unknown set of hazards, with at best the possibility of a few  
>>> years' use. I'd suggest that unless it's your father-in-law's  
>>> cabin, and you value the chance to hang out there for a week, it's  
>>> not worth your time or the customer's, especially given that you  
>>> acknowledge having little off-grid experience.
>>>
>>> Allan
>>>
>>> Allan Sindelar
>>> Allan at positiveenergysolar.com
>>> NABCEP Certified Photovoltaic Installer
>>> EE98J Journeyman Electrician
>>> Positive Energy, Inc.
>>> 3201 Calle Marie
>>> Santa Fe, New Mexico 87507
>>> 505 424-1112
>>> www.positiveenergysolar.com
>>>
>>
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