Hi all. I'm a novice when it comes to duel battery systems. I have a 05 d22 that has a duel batt system. It has a redarc sbi12 in the front and my aux battery is mounted in a box in the back tub. I have just purchased a fridge freezer and have found when I turn my ute off the fridge stays on for approx 5 mins. The little red led on the redarc stays on for the same time. After 5 mins or so the led turns off and my fridge turns off as well. The isolator is shutting my aux battery off hence my fridge turns off. Can someone please help me out to fix this fault. Thanks