Thanks for the AGM equalization info, all. My horror stories have all been with VRLAs. I will start trying the short EQ in the future after seeing the explanations.....not enough time to start releasing moisture.
Best; Dan Fink Professor of Solar Energy Technology, Ecotech Institute IREC Certified Instructor™ for: ~ PV Installation Professional ~ Small Wind Installer Executive Director, Buckville Energy NABCEP Registered Continuing Education Providers™ NABCEP PV Associate 970.672.4342 On Fri, Nov 23, 2018 at 11:34 AM Starlight Solar Power Systems < [email protected]> wrote: > Dan, Jay,… > > I’m a huge fan of equalizing AGM batteries often. Some mfg. forbid it; > some recommend it for corrective procedure for lost capacity. From 16 years > of simple observation and thousands of battery systems installed, customers > that equalize AGM’s are getting much longer battery life compared to > charging to Mfg. specs. only. > > A short EQ of 30 minutes after absorption is complete seems to be key. If > the battery is healthy, current is extremely low at the end of Absorb. > Applying 2.6 Vpc, the current rises for a short time then drops back very > low. There is not enough current or time to create heat or pressure to > release moisture. > > The EQ cycle we recommend is every 10 days or less frequently. One > customer that equalizes *daily* is at 13 years on a set of Lifeline > (Concorde) GPL-4CT batteries. Others are at 10-12 years. Customers that do > not EQ seem to get 4-6 years. > > This is all anecdotal but having some understanding what is happening in > the electrochemical process makes me a believer. Through charging and > discharging, some less active areas of the plates retain unconverted lead > sulphate after normal charging. These areas of sulfate continue to grow in > hardness and size with each cycle and eventually form a layer with strong > bonds that can't be removed through normal charging. Once this process > starts (perhaps within 30 days!), these bonds continue to increase. My > belief is that by applying a temporary high voltage after most PbSO4 has > been recombined, these areas are targeted for recombination. Slowing the > growth of irreversible sulfation results in retaining higher capacity and > thus longer cycle life. Just my opinion developed over the years it took me > to acquire a gray beard. > > Larry Crutcher > Starlight Solar Power Systems > > > > >
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