House bank is 3 AGM
105 group 31 hardwired to Prosport smart charger
Had a problem several months ago, charger
was off and batteries ran very low before I notice the problem. I recently installed a voltage monitor
. Became concerned that batteries were not holding voltage. Tested by turning off all 12v devices and the charger for 5-6 hours. Voltage dropped from 13.3 which I think is the normal maintenance
charge to 10.8. Of course when I turned the charger back on the reading jumped to a charging
voltage of 14.7.
Is it clear that my 5 year old house bank is shot? Could just one of the batteries be bad? Could this be caused by a short? I'm no electrician but it sure seems that batteries should hold charge much better then this.