battery is at 12.5 volt when "charged"
hey guys. i really need help here. in my car i have two batteries ( battery 1 and battery 2. ) recently, i upgraded an installed a battery isolator. now i have the following problem:
when my car is not running. the battery1 is at 11.9 volt, BUT the battery2 is at 7.8 (pretty dead).
when the car is running, the alternator outputs 13.8v (as normal), BUT cause of the battery isolator, the other two battaries read 12.2 volt each... so, i guess they do not charge at all?? what can i do to solve this?? better alternator maybe??
p.s don't bother answering " you should change alternator, go buy one that costs 1.000.000 euro so it has no voltage drop" or anything like that, cause i really dont think it as "help" ...