80 series 3rd battery

I can't help you with specifics on the 80 I'm afraid, but an alternative is to put it in the car near the fridge. I've done this with my GQ for a couple of trips where I expected to be stationary for 5 days+. I've used to have 8AWG cable from the second batt to the fridge. Have now got 4AWG from second batt to third in the back of the wagon, then 8AWG to the fridge and a ciggi socket for lights etc. Compressor is going back there soon.

I mounted mine into onto the base of my home built _Affordable_Storage_Drawers.aspx with a marine battery mount so it's very solid. You can also get a marine battery box so that it is fully enclosed if you prefer.

So far has worked very well for me. I have a permanently mountend temp/voltage gauge at the back as well to keep an eye on it. About the only issue I have is the bleep y 55A alternator, which appears to be dying anyway, struggles to charge them all up when the batts are really low. A few hours driving gets them up though.