# Using a 12v refrigerator with my Model 3



## June18M3

I’ve been thinking about buying a small (say 20 or so quart) 12v refrigerator for a trip I’m about to take. My plan would be to plug it into the 12v outlet in the car, wondering if anyone has thoughts on this, specifically:

—. Is the 12v plug in the car suitable for something like this, I’m not sure what the refrigerator draws but a few I looked at seem to be around 6amps, but I assume when the temp is stable it wouldn’t be drawing that continuously 

— What might the impact on mileage be

— I read that when in Sentry Mode, the 12v plug is active, so I assume I could leave the refrigerator plugged in at night without drawing the main battery down. However I’m guessing the 12v outlet is driven off the 12v battery, so a question might be will the main battery keep the 12v battery from going dead? I’ve heard the newer cars have a lithium 12v battery but my car is a 2018 LR, so mine is whatever they were using back then)


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## JasonF

That's only 72 watts, which is less than 1 kWh. So it shouldn't have a lot of impact on the battery. You're probably better off than in a gas car, where the fridge running while the car is shut off can drain the battery and leave you stranded.


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## styleruk

As far as powering the fridge whilst the car is on and running, there should be no issue as your device uses 6 amps (6x~12=~72w), I believe the socket can take 12a (12x~12=~144w).
You may find that the car has a power monitor on the 12v battery and it will trip that and power off the socket when the car is off. Can't be sure on it but it happened to me on another EV car, so drawing power that the car does not know about or manage...eg a cooler plugged into the 12v socket, will certainly trigger that. In my case, I ran a small dash camera directly off of the battery in my Smart EV and it triggered the power monitor which freaked the system out. If it does not trigger the monitor then you still risk running the 12v battery low. In my opinion, I would not do it, buy maybe there is a way.
There is one way to power a 12v device constantly without triggering it, this link is one way, but only do this if you know what you are doing and are a little brave.
http://www.cafeelectric.com/blog/2020/06/08/inverter-power-connection-1/


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## msjulie

Yes the 12v is powered whenever the car is awake so sentry mode, among other things, should keep it awake

As long as the main traction battery has charge, the 12v should be kept charged as well given nothing goes wrong


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## styleruk

msjulie said:


> Yes the 12v is powered whenever the car is awake so sentry mode, among other things, should keep it awake
> 
> As long as the main traction battery has charge, the 12v should be kept charged as well given nothing goes wrong


That's interesting and actually quite useful of Tesla to keep the 12v socket live if something is plugged in. That means the main HV battery must be charging it constantly, I always assumed that the 12v battery powered on the main HV battery. Good to know.


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## JasonF

styleruk said:


> That's interesting and actually quite useful of Tesla to keep the 12v socket live if something is plugged in. That means the main HV battery must be charging it constantly, I always assumed that the 12v battery powered on the main HV battery. Good to know.


It doesn't charge the 12V battery constantly, but when the 12V drops a certain amount the contactors close and charge the 12V from the main battery.

At 72 watts, it might suck the 12V dry pretty quickly, but the main battery has hundreds of times more power.

If you're worried about it because you are planning to be far away from charging for long periods of time (like camping) you might want to get one of these:


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## styleruk

JasonF said:


> It doesn't charge the 12V battery constantly, but when the 12V drops a certain amount the contactors close and charge the 12V from the main battery.
> 
> At 72 watts, it might suck the 12V dry pretty quickly, but the main battery has hundreds of times more power.
> 
> If you're worried about it because you are planning to be far away from charging for long periods of time (like camping) you might want to get one of these:


I agree, that was my initial thought. There must be a battery protection on the 12v battery, so using the 12v socket whilst the car is not plugged into a charge point will only power a fridge for a short time. As I mention above, same happened on my Smart EV. 
I have a 12v fridge I use in my classic car and use it when I go to Le mans or other sporting events, that's permanently on and I have a battery protection device in the boot to ensure when the battery drops to 12.5v, it switches off, that way when I pull over on route it does not drain my 12v battery too much. You'll find, (depending on the battery), an evaporative fridge will pull a battery down quite quick. In my classic, I have a large battery and that takes longer but on the Tesla, it is a small battery and that might drop down quite quick as the fridge starts to pull power, whilst not flat, it will just pull the voltage down quicker. Not that I need to have a fridge in the Tesla anyway, but if I did, I'd probably look at another way. The fridge I use in my classic is multi fuel, 12v,240v and gas. When I get to the camp site on an event, it goes straight over to gas which is far more powerful and cool beer when camping at a 24hr race is absolutely fundamental to the weekend.
JasonF, your link appears broken.


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## Spuzzz

I thought about doing this too. But then decided against it … so many varying opinions out there on how 12v replenishment works (and also some stories about 12v problems), I wasn't going to risk my EV battery (12v or otherwise) to keep my sodas cold. I like @JasonF s solution and may try it myself.


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## JasonF

styleruk said:


> I agree, that was my initial thought. There must be a battery protection on the 12v battery, so using the 12v socket whilst the car is not plugged into a charge point will only power a fridge for a short time. As I mention above, same happened on my Smart EV.
> I have a 12v fridge I use in my classic car and use it when I go to Le mans or other sporting events, that's permanently on and I have a battery protection device in the boot to ensure when the battery drops to 12.5v, it switches off, that way when I pull over on route it does not drain my 12v battery too much. You'll find, (depending on the battery), an evaporative fridge will pull a battery down quite quick. In my classic, I have a large battery and that takes longer but on the Tesla, it is a small battery and that might drop down quite quick as the fridge starts to pull power, whilst not flat, it will just pull the voltage down quicker. Not that I need to have a fridge in the Tesla anyway, but if I did, I'd probably look at another way. The fridge I use in my classic is multi fuel, 12v,240v and gas. When I get to the camp site on an event, it goes straight over to gas which is far more powerful and cool beer when camping at a 24hr race is absolutely fundamental to the weekend.
> JasonF, your link appears broken.


It's working, Amazon just likes to be stupid. Search Amazon for "Portable Power Station".


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## styleruk

ah OK, yes, a portable power station is a good safe option.


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## June18M3

I did jump in and bought the 24qt F40C4TMP from Amazon. Haven’t done a lot of testing yet, but basically it looks like this is more than doable. 
— Initially I plugged it into 120V to get a feel for how it works. Set it at 33 degrees and put it in ECO mode. The temp reading over about six hours varied from 33 to 36. I still need to try Max mode to see if the temp is more stable, but for my purposes 33 to 36 would be fine. The unit can be used as either a fridge or freezer, so I do have the ability to keep it cooler

— All these units come with a battery monitor and give you a voltage option that you can set so if the voltage falls below a set amount the unit will shut off. However, based on the comments I read in the tread, that doesn’t seem to be an issue

— I plugged it into the console 12V socket and let it alone for 21 hours. At the end the main battery had dropped 3%, some of that isn’t related to the refrigerator. As noted in this thread you do have to leave something like Sentry or Cabin Overheat on. When I had all that turned off in my garage at home, found the 12v plus is not active

— After 4 years I learned something about my M3. I put the unit in the trunk, but then I couldn’t see the readout with the trunk closed and was about to move it to the back seat when I noticed there is a small mesh window that with a flashlight I could see into the trunk and the readout. Have no clue why that mesh is there and it does seem like a security issue since anyone walking by could see at least part of the trunk interior, but it was useful for me in this case

— I bought this unit in part because Amazon had a user video where the guy used it with his M3. He had the 20qt version which fit into the trunk well, the 24qt unit is a little taller so I don’t know if it would also fit but when traveling I have the charge cable, a 20ft extension, “I don’t have a spare” inflator, etc in the well, plus I wasn’t sure about the heat (not much, but there is some) exhaust. BTW, the unit is really quite

I haven’t decided but I may go ahead and get a Jakoby portable charger, I’ve come close to getting one since I do some car camping using my Outback. Doesn’t look like I would need it for this trip in the M3 but, I need to do my part to keep the post pandemic spending and inflation rates clicking along 

Thanks to everyone for their responses.


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## $ Trillion Musk

For Model Y owners, the Iceco VLPro60S is a perfect fit in the trunk with half of the 3rd row seats folded down. https://icecofreezer.com/products/vlpro60s-12v-refrigerator


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## MachV

I traveled the country with a smaller refrigerator strapped in the middle seat in the back. I didn't have any problem running eight hours all day and I don't think it used too much electricity either. Once it gets cold it really doesn't draw that many amps. The secret is that it only drops the temperature 30 or 40°. So if it's 100° out and you park in the sun, you need to leave climate control on otherwise the refrigerator not do a good job. it's handy to have when you buy cold items at the store so you can keep them cold on your drive home. I will try to paste the Amazon link for the one I purchased.


*Wagan EL6214 12V Personal Thermoelectric Cooler/Warmer, 14 Liter Capacity, Portable Electric Car Cooler Warmer with 12/24V DC, 12V Small Fridge for Car, RV, and Camping Use, UL Listed*
Wagan EL6214 12V Personal Thermoelectric Cooler/Warmer, 14 Liter Capacity, Portable Electric Car Cooler Warmer with 12/24V DC, 12V Small Fridge for Car, RV, and Camping Use, UL Listed


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