December 12, 20205 yr A friend of mine asked me to have a look at his system as to why the batteries were not lasting. He has a Must 5kva, 48v inverter, 1800w of panels wired 3s4p and 8 x 100amp Forbatt gel batteries. The system is just over a year old. I said upfront knowing what l have read and learnt on this forum that his batteries had probably been trashed by over depleting them. Anyway had a look today and found several settings that I felt were off... Bulk charge set at 55.7v, data sheet suggests each battery should be 14.4 to 14.7 Float was at 54v, data sheet 13.4 to 13.7 His low voltage cut off was set at 44v. He also had a Bmv 700 connected with capacity at 240ah, charged voltage at 52.8v and tail current at 4%. All these settings above I feel have messed his batteries up but just wanted confirmation. I have corrected the settings in line with the data sheet and my experience with my own bank and as 3 of the batteries were showing only 10.5v under load I have reduced his bank to 4 batteries from the 8. The batteries now are only taking a charge of around 1 amp measured on the Bmv and my test meter. Is this expected? Are they all history or can I do anything to get some additional life out of them whilst they look at a plan to replace them?
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