So i've been having a strange problem wrt my electrical system and figured if anyone have had similar experiences. So a while aback, my voltmeter started to read 15v+ (overcharging) and i suspected the cause of it to be a faulty voltage regulator. I swapped out the internal one with an updated one with a 1 wire ignition controller, serviced the alternator and it worked perfectly fine but within 1 week the problem came back, only this time, the voltage dropped as opposed to overcharging as if the battery wasn't charging/ the volt regulator stopped working/ alternator died but when i tested the the alternator, it was fine and so too my grounds and fuses/relays. I have 2 other batteries in the trunk for i.c.e as well. Alternator is the zeus model 160amp version from a known powerseller and it's about 4 yrs old! What can be the issue here or where can i start troubleshooting?