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Adam_H
Explorer
Mar 26, 2015

Battery Life With a Residential Fridge

Like many RVers I decided to replace my troublesome rv fridge with a residential. I have read a lot of posts here and other places about doing so and battery life when camping without shore power. Some say you need a large bank and solar and a few said don't worry about it. We camp 1-2 weekends per year without shore power and many other times with power so adding a lot of capability for the couple of times was not high on my list but I wanted to see if it is doable with 2 batteries and a cheap harbor freight inverter. So I purchased a $45.00 inverter and set about finding out. I will be traveling with the fridge running so the TV will keep it charged easily during those times. I had an old golf cart battery in my basement for a few years so I charged it overnight (it was dead) not expecting much from it but it is still good.... Wow!!!!

I set up everything on my workbench and started testing.
The fridge was NOT cooled down prior
I started after the charger was disconnected for 12 hrs and the battery voltage was 13.16v
Hooked up the inverter and turned the fridge on. Starting amps measured on the 12v side was 75a for 1 second then it settled to 10a while the compressor was running.
Running voltage settled at 12.91v
After 2 hours I checked and the open circuit voltage was 12.82 and dropped and settled to 12.52 while it was running
After 6 hours the open circuit voltage was 12.62 and running voltage was 12.50

Remember this is from a battery of unknown life left, shockingly it performed so well that it will go back into the camper to augment the 2 that are already in there

I learned 2 things
1 I have a good battery to add (ford think cart battery)
2 My fridge will definitely run all night on 2 or 3 batteries with ease

Specs:
Fridge 6.0a starting / 1.0 running
Inverter HF 750w continuous / 1500w surge
Battery. 1 worn out golf cart battery
Charger. Cheap brand

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