Powering a fridge/freezer

[hjdca]

That's the first time I ever heard of that!
It happens all the time when you have a heavier electric load than the charging system in a car or truck can manage.
It won't charge and discharge at the same time anyway. Whatever is trying to charge the battery will handle the load until the load is gone then it will be able to charge the battery.
If the truck's inverter can run a fridge and a battery charger at the same time on AC, then it would be more efficient to run the fridge from DC and skip the conversion process of AC to DC.

I have the BLUETTI Portable Power Station EB70S, 716Wh LiFePO4 Battery, and I read somewhere that it is inefficient when charging and discharging at the same time, heats up the battery, and is generally not good for it. Although charging and discharging at the same time does work.
The battery takes 200 Watts AC for charging and the fridge burns 35 watts AC when cooling, so, it is 235 watts on the 400 watt inverter in the back of the bed when the truck is running. It is pulling from the truck alternator, so, no big deal about the efficiency. When the truck switches off the AC, then, the fridge automatically swiches to DC and it automatically pulls DC off the battery which is the most efficient.
Note: My fridge will try to pull AC first, and if is not available, it automatically switches to DC. I believe this is the most desired configuration if you want to use the AC bed outlet and an additional LiFePO4 battery.

Note: I have been running this setup now for 1.5 years with no ill effects, with lots of off roading, and badge of honor trails. The battery and fridge seem to be handling it well so far.

Here is a pic of my bed setup for The Rubicon Trail. I was able to close my hard Tonneau cover and 4wheel without worry.

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[Jaxmax]

Going to have to follow this , just got an ARB element, that I want to install above wheel well on drivers side, inside my RSI cap have a circuit already run from my Voswitch. Going to have to go over the numbers, plan is just starting but thinking perhaps a larger main battery delete small sux battery perhaps put a solar panel system on top of RSI cap should be about 100Watts. I was thinking of only using 12v charging while driving, and perhaps using the 120V when parked for a while or to precool before leaving on trip….Jack

 

[DCPHOENIX]

It might make it through the night but thats a pretty big risk IMO. Your much safer off having a aux or dedicated battery. I would not want to risk draining the main vehicle battery all night from a fridge. You may find yourself stranded next morning.

its fairly easy to do the math. Take the average running amps multiplied by, say 12 hours. That gives 2 hours after shutting off the engine, 8 hours of sleep, and 2 hours in the morning before starting the engine. So for example maybe a fridge pulls 1.2ah. 1.2x12=14.4. so 14.4 amps to power the fridge for 12 hours.

Now a AGM battery, to avoid long term damage, should only be discharged to 80% of its total rated ah capacity. I know some will argue this but its what I have gone off of for years. So the batteries that many use with the genesis dual battery system are 64 ah. 20% of 64 is 12.8. So by using that battery spec with the 1.2ah average for a imaginary fridge means you drained the battery to 77.5%. So in that case it will work with some battery life expectancy reduction.

now that is making a lot of assumptions with specifications. Point being - make sure your not draining your starting battery so low it wont start.

also that assumes a constant 12v. As voltage drops due to usage, amps needed to run an item increases. so realistically your total draw would be greater than 12.8. It also might mean the battery is so drained the fridge hits its 11.v voltage protection, or whatever spec it is set to, and shut off automatically to save the battery

so you really should do some math. Not all fridges pull the same amps

EXACTLY the type of info I was after, thank you!

My thinking was that if a 1000wh Jackery could power a car type fridge for 2-3 days, surely a car batter could do it for a night.

Better to find out now instead of out in the middle of the Ozarks!

 

[chorky]

Yeah, but dang, he'd have cold beer while he waited for help!

Hahahaha. Hey. priorities!!

Haha. Thick stuff, eh? Funny my son so far hasn’t developed a taste for it. Don’t know what’s wrong with that kid.

Uncle Sam taught me if you can't chew it, its not dark enough

I have the BLUETTI Portable Power Station EB70S, 716Wh LiFePO4 Battery, and I read somewhere that it is inefficient when charging and discharging at the same time, heats up the battery, and is generally not good for it. Although charging and discharging at the same time does work.
The battery takes 200 Watts AC for charging and the fridge burns 35 watts AC when cooling, so, it is 235 watts on the 400 watt inverter in the back of the bed when the truck is running. It is pulling from the truck alternator, so, no big deal about the efficiency. When the truck switches off the AC, then, the fridge automatically swiches to DC and it automatically pulls DC off the battery which is the most efficient.
Note: My fridge will try to pull AC first, and if is not available, it automatically switches to DC. I believe this is the most desired configuration if you want to use the AC bed outlet and an additional LiFePO4 battery.

Note: I have been running this setup now for 1.5 years with no ill effects, with lots of off roading, and badge of honor trails. The battery and fridge seem to be handling it well so far.

Here is a pic of my bed setup for The Rubicon Trail. I was able to close my hard Tonneau cover and 4wheel without worry.

I'm not 100% but 90% certain all of the fridges operate the same way. They want to use 110 first, and only will use DC if 110 voltage is not present.

Going to have to follow this , just got an ARB element, that I want to install above wheel well on drivers side, inside my RSI cap have a circuit already run from my Voswitch. Going to have to go over the numbers, plan is just starting but thinking perhaps a larger main battery delete small sux battery perhaps put a solar panel system on top of RSI cap should be about 100Watts. I was thinking of only using 12v charging while driving, and perhaps using the 120V when parked for a while or to precool before leaving on trip….Jack

Well it all depends. I know, I hate that statement too...but it's truth. It depends on each individual situation. What do you want to run? How long do you want to run it? What is the location, environment, in which you will operate?

Running just a fridge for a 2 night camping trip in northern latitudes is a vastly different power use case than running a fridge, water heater, charging drone batteries, et... while on a 2 week trip to Arizona.... So you really do need to do the math.

EXACTLY the type of info I was after, thank you!

My thinking was that if a 1000wh Jackery could power a car type fridge for 2-3 days, surely a car batter could do it for a night.

Better to find out now instead of out in the middle of the Ozarks!

Ok so here is an important distinction. The Jackery, Goal Zero, or other systems of the like are lithium batteries. Lithium batteries are VASTLY different than what is in your truck. The Gladiator comes factory with a main AGM battery, and the little motorcycle style which I believe is also AGM (@ShadowsPapa can you confirm that?). AGM batteries are what you don't want to drain past 80% SOC. Lithium, depending on a few things, can be drained basically to zero without significantly reducing the lifespan of that battery. this is why you see the YouTube guys running their fridges and other items off the 'power systems' for 2 or 3 days. They plug them in to charge them while driving, hook them to solar when camped for the evening, and use them to keep the fridge/lights going at night. But during the day those systems are charging off of the alternator.

So it is very important to understand the difference. This also does NOT AT ALL mean you can just stick a lithium battery in place of the factory battery. You'll cause one big smoke bomb. You also cannot (or rather should not) connect a lithium battery directly into the vehicle system. You really need to use a DC/DC charger for that, or you're risking a smoke bomb. If you hop on over to expedition portal.com you will see a lot of super knowledgable folks with the super big trucks (like earth roamers) talking lithium and figuring how to calculate what they need. So the takeaway here is lithium and AGM are very different. Lithium is super light comparatively, but also very expensive. For example, a 100 ah lithium battery might weigh something like 50 pounds and cost 300-500 bucks depending on who you use. But to get 100 ah out of a AGM battery, well, you would need 2-5 of them depending.... and it would probably weight a few hundred pounds.

The easiest way to do what you want to do is just get a jackery or goal zero, use that to power your fridge, etc... and charge it via solar or alternator when driving. But those things are not necessarily cheap at about $1,200-$1,600 depending... Having a permanent on board solution is nice to have and is comprable in price but you just need to really plan it out well. The first place to start is figure out what you, in truth, want to be able to run, and for how long, for how many days and if there will be driving or solar charging between those days. Also, try and get in the habit of talking in terms of amp hours. most items on a DC basis are rated in terms of amp hours. jackery and goal zero make this difficult because they talk in watt hours. watt hours are great for residential battery setups, but not so much for talking DC components like fridges, lights, etc..



So here's the thing. Will the stock gladiator battery run a fridge for 12 hours at night? Probably. But 1 or 2 or more things will happen. 1) you might not be able to restart the truck. 2) you likely will drain the battery past 80% SOC. Now...if you had a dedicated aux battery that is disconnected from the main vehicle battery and you drained it past 80% SOC, will it still function? Probably to some level. But the lifespan of that battery is drastically reduced. Now, if buying a new battery every couple years is no big deal to you, then go for it. But the other potential is if you drop below the 11v 'safety' that most fridges have, then you might wake up with all your ice cream melted all over the beer. But, your little 12v fan in the tent might still be spinning away. These systems, to do them correctly, is not necessarily complex, but does take some thinking and pre-planning to do correctly without damaging things or risking fridges shutting down.

 

[Jeepasaurus_Rex]

I've left my fridge run in my jeep (in the KJ) for 4 days off the starting battery without turning it on. But it also depends on how how it is, how full the fridge is, and what temperature you have it set at.

It should be fine overnight, depending on the above mentioned. The fuller it is, the more it'll be okay.
I always set mine to 28 degrees, and then put a bunch of water bottles on the freezer section so that they freeze over. In the event it does lose power or I need to have it off for a while, they will put out enough to keep it cool for a while.

I've also got the fridge bag/sleeve thing which helps a lot.
Mine runs even during Texas summers

 

[Donkey Fluffer]

Many 12V fridge/freezers can bet set to turn off when the battery voltage reaches a certain level, saving you the dreaded "click" in the morning.

 

[ttn333]

Charging and discharging isn't an issue. People do it all the time with solar panels and alternators. I have my fridge hooked up to a lifepo4 that's constantly being charged by solar or a victron ac-dc charger. Sometimes I even run a mini oven in the system. No problem whatsoever.

 

[Newlife]

the nice thing about a power station is it’s all in one no extra wires etc to deal with. The bad side is you’re limited to what you have. So if you have 1 12v that’s it no adding. If you have 5 usbs and need more you can add an adapter but hopefully your chord is long enough to reach the power station. For us we did the jackery 1500 and loved it it worked great. But when I started adding more things to the truck we found it’s short comings. So we switched to at first a single 100ah battle born battery and a red arc. Now we’re running 2 battleborns and the red arc which gives us at best 10-11 days of non moving power. The second the truck starts up the red arc turns on and we’re dumping 50a into the batteries.

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