Hi, I’m trying to determine if my boats 220Ah (2x110Ah) battery bank is dead or if there is another issue at play.
I have a BMV712 and the low voltage alarm has been going off after about 1hr of disconnecting the charger. The BMV is initially showing 100% and has usually dropped into the high ninetys within an hour under normal loads, however the voltage is tailing off quickly and the alarm usually sounds within the hour. There is every chance I have a dead battery/batteries in the bank, however the charge percentage remaining high is making me question this. Does the BMV determine the charge percentage as a factor between battery capacity and load over time and use this to calculate remaining capacity percentage regardless of measured voltage, or is this also taken into account?
If the two are exclusive of each other this could explain why my low voltage alarm is going off when the BMV is showing almost full charge. If this is not the case I might have some more serious issues to investigate.
Many thanks,
James