12v Fridge Battery Drain?

[tjwoods1]

I was hoping to hear peoples experience with the new 12v Fridge and its impact on battery drain when boondocking. We await our new 20' trailer that has 200w solar and lithium batteries, but have heard there might be issues with how much drain the 12v fridge has on the batteries. Will the 200w solars be enough? Our 2015 trailer ran on propane, which I prefer, but I am a bit concerned with the limitations - if any - with the new 12v fridge. If people have experience with it, or any tips, I'd love to hear them.

[PB_NB]

If it is a Dometic 3 way fridge like ours in our 2019, you can run it on propane and the battery usage is low at that point.

Full 12V by itself does consume a lot of battery reserves.

We have no problem running ours for long periods of time on propane off grid.

When we are driving, I run the 12V only and do need to get the battery back up once we are parked, by switching back to propane

[rodsterinfl]

Expect one lithium a day to be drained by an 8 cu ft model. I have done the math on the Norcold and the Dometic. They are about the same. If you are a boondocker, you will either need a bank of batteries and a generator and roof of batteries or a propane fridge. The propane one I have will run 28 days on one 30# tank.

Some people were suckered off propane by comparing the 2 way electrical comparison- not its native propane energy source.

[field & stream]

There are many, very informative, threads on this topic. The “search” function is your friend.

In summary, they are power hogs, require minimum 3-400 watts of solar panels, and if solar conditions are not good (cloudy or shaded site) will still require a generator to get you past a couple of days.

[MRA]

I have the 10CF 12v fridge and reports of it's energy consumption on this forum are greatly exaggerated.



If you leave it at a reasonable temp and do not open it excessively and use night mode you can expect not a huge amount of energy use.
Back when we only had 300W of Solar , as long as the sun was shining during the day, electricity was not our limiting factor for the length of time we could boondock. Waste water was the limitation.

[MDVan]

2021 Caravel 22' with the tiny, 12V reefer. It draws 1 to 5 amps depending on cabin temp and times we open and close. Averages 1 to 2 amps this Spring. We don't have lithium and only rooftop panel. We get 2 days before I get nervous about the battery voltage.

[uncle_bob]

Hi

Depending on where you are, your 200W panels may give you anything from zero AH in a day to quite a bit more. 20 AH a day would not be all that unusual in the northwest.

Your lithium batteries are probably 200AH. If they start out at 80% charge you have 160 AH to use.

It's a good bet that you will use at least 20AH a day on "other stuff" while out and about. (The fridge is not the only load ....).

Depending on temperature and a few other things, your fridge probably pulls between 2 and 5 AH an hour. In 24 hours it will use 48 to 120 AH just for the fridge.

Worst case scenario: you are in trouble in under 2 days. This includes drive time if you do not have a DC/DC converter.

Best case, you might make it a couple of days.

Bob

[tcgoetz]

Here's my notes:


Battery got down to 83% overnight with fridge running not in night mode. Solar stopped producing the previous night at 6pm and broke even at 8am. So, 17% of 200ah = 34ah for 14 hours = ~ 2.4ah per hour on a day with high around 70 and low around 50. (Norcold Model N8DCSSR, 8 cu ft)


More data:
Airstream 27FBQ: Power Usage and Solar Generation on a Sunny Day in April
Airstream 27FBQ: Power Usage and Solar Generation on a Partly Cloudy Day in April

[richard5933]

Originally Posted by PB_NB

If it is a Dometic 3 way fridge like ours in our 2019, you can run it on propane and the battery usage is low at that point.

Full 12V by itself does consume a lot of battery reserves.

We have no problem running ours for long periods of time on propane off grid.

When we are driving, I run the 12V only and do need to get the battery back up once we are parked, by switching back to propane

Sounds like you're talking about running a 3-way fridge from 12vdc. Running one of the new compressor 12vdc fridges from 12vdc is not at all the same thing.

The one we had in our motorhome would consume about 50-70 amps a day, so your solar should be able to keep up if you don't have a lot else running.

[BarrettArt]

Originally Posted by tjwoods1

I was hoping to hear peoples experience with the new 12v Fridge and its impact on battery drain when boondocking. We await our new 20' trailer that has 200w solar and lithium batteries, but have heard there might be issues with how much drain the 12v fridge has on the batteries. Will the 200w solars be enough? Our 2015 trailer ran on propane, which I prefer, but I am a bit concerned with the limitations - if any - with the new 12v fridge. If people have experience with it, or any tips, I'd love to hear them.

I have the 12v, too, and it definitely compromises my ability to boondock. I have 500w solar but even with bright sun, the fridge drains the battery in just three or 4 days. 12v does get colder faster and stay colder, but that’s the tradeoff. I wish I had my propane fridge back.

[JeffKim]

I'm on the side of the "12V refrigerator is not as bad as people want to make it out".

Anecdotally, we have 300W on the roof but a larger refrigerator than yours in our 25' GT. We bent an axle and had our trailer sitting at the trailer shop for a month with the refrigerator running in June in Minnesota. When we picked up the trailer the batteries were at 90% and my beer was very cold.

So, I'd try it out and see. Park it in the driveway unplugged and see how it goes. If your panels are in the sun then that's likely best case. We have ours set to where ice forms in the freezer solid but barely, so not full blast. Be sure to sample a beer every day, but a margarita party with the neighbors might be too much.

We have 4x100Ah lithium with 300W on the roof and 420W external plug in panels. Boondocking with Starlink, frig, computers, etc. we haven't run out of electricity or even come close. We watch our consumption and are frugal. But as stated above tanks are the limiting factor.

Some things to consider:

• As stated above, a DC-DC converter hooked up to the 7-pin charge line will help a lot between destinations (if boondocking on arrival). It's like having an extra 200W panel.
• Plug-in external panels are almost better then the rooftop since the roof is shaded often.

[BGClassic]

We like our 12V 10 cu ft Norcold. We can boondock just fine with 400Ah lithium, just run the generator late in the day. We've never reached 50% SOC, even after morning coffee, microwave use, etc.

[Duckear]

I wonder how much, if any, a block of ice in both the freezer and refrigerator compartment would help?

Imagine taking a couple of ice cube bins, filling them with water and freezing it at home. Put one in the fridge, and one in the freezer.

[Airkeeper]

Our frig in our 2024 BC20x works great especially when compared to our 2018 BC16 frig. The Dometic in 2018 BC16 in the summer was barely functional.

[PB_NB]

Originally Posted by richard5933

Sounds like you're talking about running a 3-way fridge from 12vdc. Running one of the new compressor 12vdc fridges from 12vdc is not at all the same thing.

The one we had in our motorhome would consume about 50-70 amps a day, so your solar should be able to keep up if you don't have a lot else running.

Yes, I was thinking that propane flame would just blow out while travelling so I switch it to 12vdc. I have a 250ah lithium battery so it does well but will show a good drop after lots of travelling.

I guess I could run it on AC as well just by switching on my inverter but I expect that this would just use more power than straight DC.

[richard5933]

Originally Posted by PB_NB

Yes, I was thinking that propane flame would just blow out while travelling so I switch it to 12vdc. I have a 250ah lithium battery so it does well but will show a good drop after lots of travelling.

I guess I could run it on AC as well just by switching on my inverter but I expect that this would just use more power than straight DC.

This thread is about using a modern 12vdc compressor fridge, not a 3-way propane fridge.

That said, neither the 120vac or 12vdc options for a propane fridge are anywhere near as efficient as running it on propane. Just run it on propane while traveling and you'll be fine.

You can use the search function to find many existing threads on the use of 3-way fridges while traveling.

[Hermes]

Originally Posted by Duckear

I wonder how much, if any, a block of ice in both the freezer and refrigerator compartment would help?

Imagine taking a couple of ice cube bins, filling them with water and freezing it at home. Put one in the fridge, and one in the freezer.

Wally Byam used to say, let's not make changes, let's make improvements.
Maybe we could go back to this technology as an improvement.

[PB_NB]

Originally Posted by richard5933

This thread is about using a modern 12vdc compressor fridge, not a 3-way propane fridge.

That said, neither the 120vac or 12vdc options for a propane fridge are anywhere near as efficient as running it on propane. Just run it on propane while traveling and you'll be fine.

You can use the search function to find many existing threads on the use of 3-way fridges while traveling.

Hi Richard, I lost that part in hurry to write a response to the OP. Sorry for the attempted derail!

It would seem that this new modern fridge design is leaps ahead of the rest to the trailer tech! Perhaps a little generator or beefed up solar/battery would be needed to keep the boondocking situation workable?

[field & stream]

The post above that says with 400Ah of lithium batteries they still run the generator every day shows what you are up against. Also, some of the experiences posted omit the ambient temperature, which is essential information. The duty cycle you will experience is critically dependent upon ambient temperatures; at 70 degrees a 50% duty cycle is a reasonable expectation, but in the 90’s with warm nights you will be closer to 90%, or double the usage.

[Redbarron55]

We have a Norcold unit that draws about 5 +- Amps when running and it is a little less than 50% duty cycle.
That averages about a 2.5 Amp continuous load on the system
We have 600 watts of solar on the roof and that does a pretty good job of charging the 300 Ah battery system. That consists of 3 100 Ah Chin's batteries in parallel.
The Victron Smart Shunt (which I highly recommend) tracks the usage of power and the voltage and current etc of the system pretty well.
I find that the basic 12 volt loads as minimal and the refrigerator is the major night time load that needs to be replaced by the solar cells. That accounts for around 12% of the available power per night. We also have the TV and lights etc on 12 volts and there is a 2000 watt inverter to power an induction hot plate and the microwave (not used much).
I believe that the LiFePO4 batteries will easily power the trailer for several days with poor sunlight. With poor charging we do regain a little power stored, but don't necessarily get back to 100 percent.
One thing to remember is that you can discharge the LiFePO4 batteries very much lower than the lead acid batteries without damaging them.
We have a Progressive Dynamics PD-4560 that will recharge at 60 amps to recharge the batteries from either shore power or the small 2200 watt LP or gasoline generator we use. The batteries will recharge at a pretty high rate (up to the max available from the charger up to 300 amps ( 3 x 100 Ah batteries) so a good charger helps limit the length of time the generator has to run to recharge the battery bank.
If you have a single 100 Ah battery the refrigerator will use about half of the charge, two batteries about 1/4 of the charge and three about 16% etc. overnight.
Your mileage will vary...