Re: [VACList] Running the Refrigerator from a converter?

[Matt Worner <wornmatt@xxxxxxxxxxxxxxxx>]

Paul,

I've heard, no guarantee how accurate my information, that the fridge draws
about 3 amps at 120 volts.  That would equate to 30 amps at 12 volts.  If
your inverter were 100% efficient (and of course it won't be) you would draw
a fully charged 80 Ah coach battery down to the 50% level (usually
considered the lowest you should go) in about an hour and 20 minutes of run
time on the fridge.  What is the run time for a closed fridge in an
unconditioned trailer?  How hot outside?  Hard to say without empirical
data, but for the sake of argument figure 50% duty cycle.  Now you are up to
2:40 of run time, again just on the coach battery.  Can your truck
alternator replace the juice that fast?  On the powersmoke, probably.  After
all the alternator is designed to refill two honkin' batteries under the
hood.  On a normal vehicle with only one battery and smaller alternator, I
would tend to doubt it.  The only way to find out is try, except that if the
answer is no, you got a (or in our case 2) dead battery in the tow vehicle.
I'd test it driving around the block all day, never traveling beyond walking
distance to the house before taking it on a trip, though.

We use frozen milk jugs in the fridge to keep the contents cool when on the
road, and a peltier cooler on the floor for the stuff that needs cold.
Works well so far.

Matt