Hello I hope someone can help as I not sure about this. I have a 8 Amp car battery charger; so in theory the time it should take to charge a 36Ah battery is (36/8) = 4.5 hours. The thing that's throwing me is the needle on the charger; when I first hooked up the charger (to an almost dead battery) the needle was reading 5 Amps, now about 7 hours later the needle is reading 2.5 amps. So in a nutshell is my 8A charger really not charging at 8A, as the needle shows 2.5A, and so it will take longer to charge that 4andahalf hours wont it. Thinking about; as the needle progressively drops down towards 0 it will slow down in charging. Am I right about this it really should not be this confusing should it.