Hi all, Im more or less a total newbie to all things 4x4, ive been researching as much as possible and have found tonnes of great stuff on here. When i search 'Dual battery' setups, there are millions of hits and i dont know where to begin. Ive been reading that newer vehicles often use a variable voltage alternator to keep emissions/fuel consumption lower. This apparently means that i cant simply use an isolator/diode to split my batteries. Lots of people talk about using a dc-dc charger set up to get full charges to both batteries. Fair enough, but couldnt i just set up my batteries in parallel and my ute alternator would just see it as a really big battery and just charge it up almost as it normally does? Couldnt i then just have an electrical diode to restrict the battery flow one way, so the main battery is for cranking and the second then is hooked up to fridge etc? This would mean that the fridge could never draw elec from the cranking battery, right? When i research and find Aus sites its all dc-dc/bcdc etc, but in US they seem just to put them in parallel. Similar in UK, no one even seems to have heard of the dc-dc charger system to set up dual batteries? They just connect batteries via the towbar cable into a camper/caravan. Any thoughts? I have a Ranger 2017 and i am trying to find a simple, yet definitive way to do this, wiring and all.