It is normal for the fridge to be lp gas or 110ac
12v operation is not normal
They used to make fridge with 12vdc operation, but it was a travel mode for maintaining cold with out using the lp
It was never very efficient , and was phased out a long time ago
Your Mallard does not have a DC option, but it must have 12 volts for the control board, or it won't come work on LP or 110v
11.82 is not totally dead but it is between 30-40% charge status, and needs a good full recharge
Modern batteries are 12.8v or above when fully charged
