It appears that the battery monitor is maybe not calibrated correctly, as the % reading has always been 90-100%, yet things have recently stopped working and the voltage is getting lower, 10 instead of 12-13. I’m new to this and not super knowledgeable, just trying to find some help to get things back working properly. Thanks!
I have the victron energy bmv-700 monitor, and mppt 100/30 solar charge controller. The inverter is 1500 watts 12vdc to 115vac and 3 12v agm sprinter batteries. Is there anything else you need to know?
Guessing the inverter is non-victron. Can it charge as well?
Does the BMV show a charge current from the MPPT?
BMV will set charge to 100% if voltage reaches setting, current drops for the set time to the set level or lower. With solar charging, clouds can cause false sync to 100%, this may explain the high state of charge, means you need to check the settings for charged voltage, time and tail current.
But if battery is dropping to 10V it suggests that solar not keeping up with load, batteries need replacing, or fault in inverter draining batteries. Could also be that the shunt for the BMV is not wired correctly. Is anything, except the BMV battery terminal connected to the battery negative? There should be nothing, and the battery ground/earth should be through the load side of the shunt.
