HighwayJunky wrote:
Domestic as far as I can determine. No visible indicator on the unit to indicate which energy source is being used.This is a Whirlpool Brand.
you're referring to a residential-type refrigerator. these are powered only by shore power...110-120VAC or your generator unless your RV came with an inverter and the fridge is connected to the inverter. if this is a new RV it almost certainly has an inverter that will power the fridge but if you bought used the easy way to determine if you have an inverter powering the fridge is to unplug from shore power, don't run the genny and then turn on the fridge and see if it powers up.
how long your fridge will run on the inverter depends on your battery bank both how many batteries, their capacities, age, how well they hold a full charge, and what else is being powered by the inverter.
we have a 2000-watt inverter and four 12-volt gel cells. I don't know the capacity of each battery off the top of my head but our inverter easily powers the fridge during our driving day because the coach batteries are kept charged by the motorhome's alternator. we very, very rarely dry camp and our fridge will continue to run overnight. our inverter powers our 3-door fridge, microwave/convection oven, TV's and related entertainment pieces as well as several outlets throughout the coach.
simple math should give you a rough idea of how long your batteries will power the fridge. essentially, you need to know how many amps your fridge consumes while it is running. first, check your owners manual and see how many watts the fridge uses then simply divide the watts by the voltage (I use 115VAC as it is an average between 110 and 120VAC). the resulting number is the number of AMPS consumed by the fridge. let's assume that your fridge draws 1000-watts of power. 1000/115 = 8.7-amps. so if you run the fridge for 10-hrs it would consume 87-amps. pretend you had a single 12-volt battery rated for 100-amps. that battery would be nearly depleted after 10-hrs assuming the only device drawing power from that battery is the fridge. your owner's manual may also tell you the amperage draw.
you need to know what runs off the inverter, the total capacity of your house batteries and the power (wattage) each of the items running off the inverter uses. the endurance of your batteries also depends on their state of charge. are they band new or 5-yrs old? have they been maintained properly or ignored? this is just an example and I've tried to keep it simple since we're talking concepts.
this article and others you can find with a google search will explain how this works and I'm sure others will chime in.
good luck.