Trailer storage, on 110v.

Nominal source voltage in N America is 120 vac +/- 5%, not 110, not 115, not 117. A gas absorption fridge in the electric mode will draw no more than 3 amps @ 120 vac, a true 1500 watt heater ~ 12.5 amps @ 120 vac. In reality, the fridge will cycle so the heating element cycles on/off as required, and rarely will any so-called "1500 watt" heater actually pull anywhere near that much. I can easily run my fridge and an electric heater on a standard 15 amp receptacle in my workshop by simply plugging the trailer's main service cable into it BUT the key is I've measured each electric heater I own with a Kill-a-Watt meter and know what each of them draws on each setting, the result being total draw is always well below 15 amps. As long as the battery is properly charged and the converter is therefore only idling there's no reason one can't run the fridge in the electric mode and heat the interior of the camper with an electric heater using a 15 amp 120 vac source.