Todd I've heard the same arguement, as well as its inverse. The battery choice was the decision of the system owner. I know they are more sensitive to charge/discharge abuse but I see the full charge rate last week at 52.xx V, just like day 1and I trust the Trimetric and the Sunny Islands. We're taking down the entire system to upgrade & install a 400A transfer switch so the batteries will have time to stabilize for the VOC check & cleaning. I guess a more accurate question would be is it good enough to properly check cell VOC and not bother with the discharge capacity check? A compromise could be cap check 12V blocks of cells instead of all 24 separately. Or is the capacity checker a waste of money. Jim
----Original Message----- From: [email protected] [mailto:[email protected]]on Behalf Of [email protected] Sent: Monday, October 04, 2010 2:23 AM To: RE-wrenches Subject: Re: [RE-wrenches] Battery capacity testers I know many on this list disagree, but this sounds SO typical for sealed batteries. It is why I never use em... never! If they are 5 years old, you are probably at the limit of their life. Replace em with flooded lead calciums and your customers (and you) will be happy for 20+ years. my .o2 Todd On Sunday, October 3, 2010 9:28pm, "North Texas Renewable Energy Inc" <[email protected]> said: I have a customer with a set of 24 Concord PVX-6480s that have twice failed during grid outages during the night. No large loads are on the critical load panel and, since it's at night when they drop to 50% dod, I'm not sure what's up with them. I plan on cleaning and retightning all the cable connections first to eliminate that possibility then checking VOC of each cell. Eventually we'll install a 25 kW genset but my first task is to find out the state of the batterys. The system turns five next spring so I don't think they are near an early death. The BOS is 2 Sunny Island 4248s with upgraded chipsets and the charger is set to spec though that may need to be bumped up. The only culprit I suspect is the high summer temperatures in this unconditioned equipment room. Finally it may be time to invest in a capacity tester. What brand is popular among those Wrenches with lots of experience in diagnosing a batterys health? The Concord DC5000 only comes in 12 & 24 V models and these are 2V cells. Thanks as always Jim Duncan North Texas Renewable Energy 486 W.N. Woody Road Azle Texas 76020 NABCEP Certified Solar PV Installer No.31310-57 TECL 27398 [email protected] 817.917.0527 www.ntrei.com Sent from Finest Planet WebMail.
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