While an almost unlimited number of things can go wrong in a battery bank, there are a few signs and symptoms common in RE systems:
One of the best ways to track your batteries’ health is to keep regular, precise records. During your maintenance checks, measure individual battery or cell voltages, and check specific gravity for flooded batteries. Ideally, readings should be taken after the batteries have been at rest for 12 to 24 hours and are fully charged, but this is generally impossible in an off-grid situation. Checking after 30 minutes of rest (no loads, no charging) will still give you good information.
These checks can alert you to bad cells, or let you know if the entire bank may be on its way out. Any differences in cell voltages or SG indicate you may have a failing (or failed) cell, and checking your readings against the expected SOC will tell you if they are losing capacity. The sooner you spot a problem, the more likely you will be able to fix it.
Lena Wilensky owns Nunatak Alternative Energy Solutions, a small RE design and installation company in the mountains of Colorado. She is a Solar Energy International instructor, a NABCEP-certified PV installer, and is certified by ISPQ as a PV Affiliated Master Trainer.
“Managing Your Batteries” by Dan Fink in HP142
“Battery Box Design” by Allan Sindelar in HP141
“The Top 10 Battery Blunders—And How to Avoid Them” by Windy Dankoff in HP114
RE Battery Manufacturers:
Concorde Battery • www.concordebattery.com
Crown Battery • www.crownbattery.com
Deka/MK • www.dekabatteries.com
Discover Energy • www.discover-energy.com
Exide Technologies • www.exide.com
Fullriver Battery • www.fullriverdcbattery.com
Hawker • www.hawkerpowersource.com
Interstate Batteries • www.interstatebatteries.com
Solar-One/Enersys • www.hupsolarone.com
Surrette/Rolls Battery • www.surrette.com
Trojan Battery • www.trojanbatteryre.com
Universal Power Group (UPG) • www.upgi.com
U.S. Battery • www.usbattery.com