Going to boondock for the first time this weekend at Loft Mountain Campground in Shenandoah National Park. I am a little concerned because I have one of those new residential fridge setups that does not run on propane, and the camground only allows generator use for very limited hours in the morning and afternoon. I will be relying on my inverter and four house batteries.
Will I be able to run my fridge overnight without the generator? Maybe I should avoid using the freezer by turning up the freezer thermostat? Have YOU ever boondocked with residential fridge?
2008 Gulfstream Tourmaster
2011 Honda CRV
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No! But the numbers do not look good. My new GE beer fridge draws 1.2 Amps at 115 VAC. That translates to 12 Amps at 12VDC, that is about 100 Amp Hours in 8 hours, you can take it from there....
You should be concerned. You can run that fridge overnight, but, depending on outside temps, expect those batteries to be very hungry in the morning. And make sure they're fully charged before nighttime.
Can't speak for Gulfstream, but most manuf use more batteries and a dedicated inverter for the res fridge. The gen running a couple hours during the day should work to peak them up. How are you fixed for solar?
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We have a residential fridge. While traveling, we keep the doors shut and it keeps every thing cold for six hours. Never have tried it for longer but I'm guessing it would go longer. So I would think that if you run your generator every six hours or so until the refer stops running it would be fine.
We do it all the time, but have 8 golf cart batteries. Here are the round numbers: a pair of golf cart batteries will provide (at the 50% discharge level*) about 1kW-hr. Our residential fridge pulls an average of 80 Watts, so one pair of full batteries supplies 12.5 hours (1000W-hr/80W). Two pair would provide twice that, 25 hours, but with no other loads.
If you charge you batteries in late afternoon, and conserve power with your lights and electronics, you won't have a problem making it through the night.
Since you are likely to run lights, your entertainment system, fans, your computer, etc., you will have to make sure your battery bank does not discharge too far: keep your batteries at 11.9V or higher to preserve battery life.
Now, regarding recharging, you probably have an inverter/charger that will supply about 100 to 150A. For 100A, at 12V, you would get 1.2kW-hr, enough for one pair of batteries each hour.
Your fridge's total energy use is about 2kW-hr per day. One way to look at it is, if you completely charged your batteries once a day, they would run your fridge and nothing else. If you charge more frequently, your batteries will be able to keep up with other loads.
Round numbers, I'd say you would not have to conserve power much if you ran the generator about 2 hours in the morning, 2 hours at night (4 kW-hr total).
Alfa Founders came with 6 batteries, and I have not heard any complaints from other owners. 4 batteries does seem a little skimpy for a residential fridge. I welded a frame for two more, and added a ton of solar. The capacity of my system is enough so the batteries are charged at the end of the day the batteries stay above 11.9V each morning. Of course the solar is just to avoid running the generator.
The other thing I hear from owners with residential fridges is, they'd never go back to propane.
I have boondocked extensively on electric only. I have a Dometic rm2510 single-door fridge, which draws a steady 175 watts on full power. AFAIK, this is similar to the average draw of a residential fridge. I have 4 6-volt batteries (440 ah total) and the fridge makes it through the night just fine.
I would caution, however, if you have limited generator hours you will likely find yourself in a bind. Since I am 100% electric, including microwave and water heater, I count on running the gennie twice a day, roughly 4-5 hours total. But when I boondock I have no neighbors, and can run the generator when and how I please. It sounds like you are doing dry camping in a campground.
If you want to maximize the efficiency of your fridge, learn to keep the door shut. Also, anything that you can freeze, do so, even if it's going into the fridge. The more very cold items in the fridge, the better it will recover from having it's door opened.
Certain veggies don't need to go in the fridge at all, especially over a long weekend. Similarly, sodas can go in an ice chest, and get left out at night (unless you have bears). And think twice about putting warm leftovers into the fridge, unless you want a warm fridge.
With 4 batteries you should be fine, as long as you have sufficient gennie time and don't abuse the fridge.