i'm installing a DC 0400 Norcold fridge in my 83 westy. the manufacturer recommends not having any appliances wired between the auxiliary battery and the fridge as to avoid some fluctuation electrical phenomenon that i don't understand. i have a large gauge wire coming off an isolator in the engine compartment coming to an auxiliary battery under the front seat. i have an inverter wired off of the aux battery and was thinking of placing another larger deep cycle battery under the bench seat to boost total amp hours out of my auxiliary system. can anyone think of a reason why this wouldn't work?

thanks,
tim