Dometic frig's:
12V DC connection
RM2451, RM2551, DM2652 & DM2852: These refrigerator models are not designed for 12V DC operation of the cooling system. However, 12V DC must be supplied to operate the controls.
RM2354, RM2454, RM2554, DM2662, DM2663, DM2862,DM3862 & NDM1062: These refrigerator models require a continuous 12V DC supply to maintain the automatic energy system.
With fridges with the DC operating mode:
The input battery voltage must rise above 12.8 volts for 25 minutes before DC operation can resume. As soon as the input voltage rises above the required 12.8 volts, the DC mode lamp (F) will illuminate; however, the control system will remain in the 25 minute delay mode and operate on gas. This delay is to allow sufficient time for the vehicle charging system to recharge the battery. If 120 volt AC becomes available during the 25 minute delay, the control will automatically switch energy source.
DC VOLTAGE REQUIREMENTS
The operational range of the unit is a minimum of 9.6V DC to a maximum of 22V DC, the unit will automatically shut down until voltage has decreased to 18V DC. The refrigerator requires at least 9.6V DC for proper operation; however the panel lights will continue to illuminate until voltage has dropped to 4V DC or below.
AC VOLTAGE REQUIREMENTS
Proper Operating Range is 100 to 132 Volts. If voltage drops below 100 volts, cooling efficiency will decrease with voltage decrease. The refrigerator will not switch to another mode of operation until all AC power is lost.
Also, on my battery box are warning labels for the landing gear - battery installed and charged for landing gear operation. Too low of a voltage and you will blow fuses (speaking from experience).
