Originally Posted by
bassboy
You need a split charge relay...Stinger SRG32 is the best one. There are also cheaper 180a relays available.
The relay will isolate the batteries when the car is off and link them when the car is started.
As for dedicated ICE batteries, you want something like Yellow top or Shruken (entry level), followed by Kinetik, Oddyssey (mid level), followed by XS Power (top end)
That wont do what Dojj is asking for as if he is saying he wants to be able to run the system with the engine running and it only flatten one battey though. Thats just the same as a caravan split charge relay but a bit more meaty (as they only tend to be about 35A IIRC)
Correct answer of course is that the alternator should be upto the job in the first place.
What sort of current draw of ICE system are you talking about Dojj?