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-boun...@lists.re-wrenches.org > [mailto:re-wrenches-boun...@lists.re-wrenches.org] On Behalf Of Allan Sindelar > Sent: Wednesday, December 29, 2010 10:41 AM > To: dahlso...@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 > al...@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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