When I first received this battery last fall (ordered on August 26, 2022. order # 12436) the CALC capacity was 185AH on my 100AH, 12V battery. It remained there after the initial two calibrations. But sometime last winter the app was updated and then the CALC capacity dropped into the 80AH range. I then went and recalibrated (discharged until 0% SOC, then charged to 100% SOC in ABC-BMS) three times and the CALC capacity was always about 86-87 AH. So that's a problem.

But sinced my last calibration, everytime I go through a partial discharge/charge, (say SOC down to 75%, then recharge to 100%) the CALC capacity drops just a bit further. You can see below that it is now down to 69AH.

Because of my belief that this is a bugged number, I installed a Victron SmartShunt - when set to the nominal capacity of 100AH, it always shows a higher SOC than the ABC-BMS app - the more the CALC capacity drops, the greater the separation between the SmartShunt and ABC-BMS.

The second issue is cycle count. When I first received the battery the number was 115 and would not ever change. Now after a calibration cycle of 100% discharge, 100% charge, it does increment. Otherwise it does not.

So. do I have a faulty battery, a faulty BMS, or is the ABC-BMS app completely wrong and my battery is fine? I have yet to do another complete discharge/charge cycle to see what the SmartShunt says the actual capacity is, but I guess that is next. The battery had zero use over the winter and was kept at SOC of 100%.

Any thoughts?