With my agm leisure battery fully charged and off charge it sits about 12.8v ( measured with meter) when I turn on my tv and a few lights the current draw goes up to about 2.5 amps but my battery voltage drops to 12.4v. When I switch them off the battery voltage recovers to 12.8v. I’m pretty sure it never used to do this and would sit about 12.7-12.8v with the tv and a few lights on and gradually drop over time. Am I worrying unduly?
