My wife and I are getting close to purchasing our first 5th wheel 2 of the models we are looking at have residential refrigerators. A friend of mine said he intentionally avoided a residential because on days he Pulls the 5th wheel to work so he can head straight to the campground, he is worried the fridge would drain the battery on the RV as well as possibly draining his TV batteries. About how long could I expect 2 12v batteries in an RV to last before the fridge would drain them?I know depends on the reserve capacity of the batteries, but I'm wondering if they would be drained in a 9 hour period.

Residential 22 cf here. We have a 2 12 volt batteries that allows our fridge to run off the inverter for over 15 hours without any problems.

Less then 24 hours. If you plan on camping off grid you should think about getting four batteries and 600 (or more) watts of solar.

I have gone over 20 hours without power to my residential refer due to a bad transfer switch. Everything was still frozen, the refer portion was still within safe temperature limits. You do need power to the refer 24/7

Thanks for the replies. My only concern was could I get through a work day if I pulled the rv to work so I didn't have to go home after and then backtrack again. Off grid we would have a generator.Now that I think of it, if I had two 2800/3100 champion generators in parallel, and the fridge air compressor kicked on with one 15,000 and one 13,500 btu AC running, would I have enough power?This is a minor concern as it would only happen if we would ever decide to attend an outdoor concert/camping event in the future.

mrad,If all three happened to start at the same second, there might be a concern. But that concern could be met by having a load support hybrid inverter/charger.

Running a residential fridge on 12 volt power? | Good Sam Community

21 Replies

MrWizard
Moderator
Aug 06, 2020
Boy oh boy
Replies all over the place
All he wants to do is keep the fridge cool during one day of work, so he can leave after work and go directly to the campground,
Answer is usually Yes
One pair of deep cycle batteries can handle the load for the day, plug in at home overnight, start the day with a cold fridge and fully charged batteries, if possible park the RV So the afternoon soon is Not shining on the wall behind the fridge
pianotuna
Nomad III
Aug 06, 2020
ktmrfs wrote:
Lwiddis wrote:
With an adequate solar system this issue would disappear....batteries, panels, wire and controller.

adequate solar AND SUNLIGHT. A few days of cloudy skies or a shaded campsite can put a real damper on batteries.

Just another reason I'll be going to SiO2 chemistry next summer.
ktmrfs
Explorer II
Aug 05, 2020
Lwiddis wrote:
With an adequate solar system this issue would disappear....batteries, panels, wire and controller.

adequate solar AND SUNLIGHT. A few days of cloudy skies or a shaded campsite can put a real damper on batteries.
AllegroD
Nomad
Aug 05, 2020
BTW, OP, Will your work let you run an extension to a 15/20 amp circuit for a couple hours?
AllegroD
Nomad
Aug 05, 2020
theoldwizard1 wrote:
AllegroD wrote:
OK! I will start with questions.
1. Is your charge line between truck and trailer adequate? If so, then getting to work and from work to camp site is not an issue.

Regardless of the size of the wire between the tow vehicle and the trailer, it is impossible to FULLY charge a discharged battery bank from the vehicle. It will prevent the house battery from discharging below acceptable levels.

Well ya got me here. I do not know what part of my post you are talking about. I did not say he could get a full charge.
theoldwizard1
Explorer II
Aug 04, 2020
AllegroD wrote:
OK! I will start with questions.
1. Is your charge line between truck and trailer adequate? If so, then getting to work and from work to camp site is not an issue.

Regardless of the size of the wire between the tow vehicle and the trailer, it is impossible to FULLY charge a discharged battery bank from the vehicle. It will prevent the house battery from discharging below acceptable levels.
Cummins12V98
Explorer III
Aug 04, 2020
valhalla360 wrote:
Cummins12V98 wrote:
Drove from SoCal to DFW, TX with three two hour stops with engine running and upon arrival Residential Frig was 38 and freezer 0 degrees. Truck charges RV batteries to provide power to Frig.

I believe the OP is intending to park at work, turn off the engine and then 8-12hr later after his shift is done, start up and head to a campground.

I doubt he wants to leave the engine running the entire time he is at work.

Did my speed reading!

No way will batteries be fine that long in warm to hot weather......unless you add some solar panels.
valhalla360
Navigator
Aug 04, 2020
Cummins12V98 wrote:
Drove from SoCal to DFW, TX with three two hour stops with engine running and upon arrival Residential Frig was 38 and freezer 0 degrees. Truck charges RV batteries to provide power to Frig.

I believe the OP is intending to park at work, turn off the engine and then 8-12hr later after his shift is done, start up and head to a campground.

I doubt he wants to leave the engine running the entire time he is at work.
time2roll
Nomad
Aug 04, 2020
The battery will be fine at work for 10 hours. Same as the battery (near full charge) will be fine overnight while you sleep. If your generator can start and run both A/C the fridge will be a minor blip. Worst case the included inverter will start/run the fridge direct if you turn the breaker off to the branch circuit that feeds the fridge.

Depending on your experience and usage patterns you may want to eventually add solar and another pair of batteries.

If the RV comes with a WFCO converter you might need upgraded charging sooner than later. WFCO is notorious for a slow charge at 13.6 volts and not going to boost mode (14.4v) when expected. If you are running the A/C 12+ hours a day this is less of an issue.
AllegroD
Nomad
Aug 04, 2020
OK! I will start with questions.
1. Is your charge line between truck and trailer adequate? If so, then getting to work and from work to camp site is not an issue.

2. What inverter is in the rig? What RR is in the rig? Look at the data plate. My Samsung RF18 sips at 3 amps. Some do sip a little more.

Our MH has the 2 GC2s at 230ah and a Tripp Lite rv1250ulhw inverter/charger.with nothing running but the RR (and parasitics), we last 10-12 hours, with outside of 75 degrees, in the sun. Fridge stays 34 and freezer at -2.

New batteries should be no problem. If work day exceeds 10 hours then maybe go out at lunch, check and run the engine or gennie for an hour, if possible.

Have fun. It will work.