On 12VDC and Propane my DM2652 uses 1.2 amps when actually cooling (almost none when not). So say without opening the door it turns on for 10 minutes every hour to keep the frozen stuff frozen it will average 1/6th of 1.2 amps every hour or 0.2 amps average.
If the fridge and the propane leak detector (0.2 amps constantly) are the only things using power and you start with a fully charged 75 amp hour battery, then your battery will last 75 divided by 0.4 amps or 187 hours.
This is NOT what you will get. Just what I think you might get under optimum conditions. If the camper is in direct sun on the side of the camper with the fridge you will get less. Maybe much less if its hot out and it runs more often.
G. CLIMATE CONTROL
During the summer months of high temperatures and humidity, the metal frame between the freezer and fresh food compartments may have water droplets forming. The number
of water droplets will increase if the vehicle isn't air conditioned during these months.
This refrigerator comes standard with a 12 volt (DC) climate control that will evaporate the water droplets when they form.To have the climate control on, you position the switch ("C",
Figure 10) located beneath the top decorative strip that houses the control panel to ON. The climate control can be left on continuously or only used when temperatures require
THE CLIMATE CONTROL WILL DRAW 12 VOLT DC POWER CONTINUOUSLY WHEN IN THE "ON" POSITION. IT SHOULD BE TURNED "OFF" WHEN A CHARGING
SOURCE IS NOT AVAILABLE. IT WILL QUICKLY DRAIN THE CHARGE FROM A BATTERY.
Lou and Laura with Bella - German Short Hair Pointer
2008 GMC Sierra 2500HD Crewcab SB Allison Duramax
2010 Flagstaff 8526RLWS - Superglide 3300
HAM CALLSIGN - KC3FFW