I’m installing a dual battery system in my vehicle. There will be the starter battery/alternator combo and a secondary auxiliary battery that will charge VIA a 30A DC-DC charger that will turn on upon detecting alternator voltage. Now, if I may say so myself, I’m over engineering this. 4 AWG cables will be used. I know it’s over doing it but in the process I will install bus bars for possible future expandibility.
The 4AWG should handle 200A draw without issue, which is more than what my 2.2kW starter would draw. I’m thinking about installing an emergency bypass switch so that in the event the starter battery fails I can start the vehicle with the aux battery.
What I’m curious about, which I don’t think will be an issue, but I’m curious nonetheless is when you have a dead battery and a fully charged one, how much current flows between the two? I’d imagine the immediate inrush current is probably very high. Short of testing this myself it’s not something I’ve been able to find a lot of information on.
The 4AWG should handle 200A draw without issue, which is more than what my 2.2kW starter would draw. I’m thinking about installing an emergency bypass switch so that in the event the starter battery fails I can start the vehicle with the aux battery.
What I’m curious about, which I don’t think will be an issue, but I’m curious nonetheless is when you have a dead battery and a fully charged one, how much current flows between the two? I’d imagine the immediate inrush current is probably very high. Short of testing this myself it’s not something I’ve been able to find a lot of information on.