Evening guys I have recently had a dual battery system installed with a red arc isolater (arb artarmon) to run my fridge and my main battery has gone flat and I couldnt start my mighty patrol, I think it is from blaring the radio while I was installing my roof top tent, I may sound like a retard but I thought that the point of the isolater was to drain the secondary battery straight away and leave the starter battery alone?? I have a volt meter in the back of the car and it was reading 12.6V at the time (which I found strange) do the accessories run straight off starter battery and that is why it is flat? Thanks guys I am a bit worried as my partner and I leave on Saturday for a round oz trip and I do not want to be out woop woop with a flat battery!!