Joe replied:

Luke,

I faced the same question when I had my dual battery system fitted, but for me the answer was easy. As the fridge (which is my main reason for getting the second battery) has its own low voltage cutout I didn't feel it was necessary.

A buddy of mine uses a 12 volt fan powered from his battery and he finds that the fan starts protesting when the battery charge drops much so he has a built in safeguard there as well.

So, the question is what do you intend to run off this system?

Joe

Mike replied:

Luke, I had the battery cut-out fitted as extra insurance. It hasn't operated yet but I believe it will protect my fridge and other equipment from low voltage damage. Incidentally, mine is a Pirhana unit which cost less than $100. Happy trails, Mike.

Joe replied:

Ah yes, the Engel fridge!

Engel have a separate low voltage cutout available for use with their fridges. They are pretty much alone in offering this as an after market accessory. Check out the pricing on that device too, but if it is close to the pricing for the ARB (or Pirhana/TJM etc) cutouts then I would stick with them instead.

Joe

Mark replied:

Luke,
If you have a second battery (isolated) then you are probably more concerned with damaging the battery/fridge than starting the car? so why not buy a cheaper inline voltage cutout from Kmart (around $20). I used one of these when I hired an Engel fridge on occasion, worked fine most of the time although it did cut in a bit late once and I had to get a jump as I only had a single battery. Should be fine to stop the battery getting completely discharged though. Has ciq plug/sockets attached also so quite handy.