Ever wanted to be able to power appliances like fridges or induction cookers in your 4wd, caravan or RV? The system should isolate and protect the starting battery from the power drain. The power should be drawn from a completely separate battery to that of the starter battery. The system should be capable of bringing the secondary battery to aid vehicle starting (if applicable). The alternator should charge the starter battery first and then divert power to the secondary battery automatically. Dc-to-Dc charging is a desired option as its ability to fully charge a secondary battery is achieved. Cable sizes play a massive role in the system especially over great distances through Anderson connections. Having the incorrect size cable can rob your system of charge. Correct monitoring of the system is just as important as the system itself.