Residential Fridge battery run time

JimK-NY wrote:
...My thoughts and calculations show way less than 2 days. The 2.5 amps @ 120 is 25 amps @ 12 volts. You have 6 x 225 AH @ 6 volts which is 675 AH @ 12 volts. Draining battery bank to 50% gives you 338 AH @ 12 volts. 338/25 = 13.5 hours. Your inverter will cost you about 10% so somewhere around 12 hours. So you will need to fire up the generator about every 12 hours. You need to replenish 338 AH. If you have a good sized charger of about 50 amps that will take about 7 hours to reach a partial full charge. So 14 hours of generator time per day. Every few days you should consider running the generator full time for 24 hours to bring the batteries up to a full charge.

Of course this is based on the compressor running full time. Run time is a big variable and could be much less if the ambient temps are cool, no warm items are added and you don't open the door frequently or for long periods. I would not count on dropping below about 60% compressor run time. That would cut your gen time by several hours a day but probably no less than about 10 hours.

Thanks, JimK, for helping get more accurate numbers there. :)

Yes, if one assumes 100% compressor run time, and no more battery depletion than 50%, then about 12 hours is probably about right. Maybe less, depending on what other loads are put on the batteries.

I know the compressor run time for us is way lower than 100%, and I don't mind occasionally letting the batteries deplete a little below 50%. That being the case, I'm probably somewhere around 20-24 hours before we would have to run the generator some.

And, that is about what I expected for boondocking more than a day with this rig. We'll just plan on running the generator a few hours during the day to recharge the batteries. Depending on where we are, may well need the generator a good bit during the day anyway, so we could run the air conditioner and keep everything else cool, too.