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12V Accessory Socket fails when I use it to power my 12A portable air compressor

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Hmmm you've got me worried now and I'm going to go and try the tesla compressor before I end up stuck in a dark lane somewhere.

I'll report back.

I topped off my tyres this evening as the cooling autumn weather in the UK had reduced the pressure.

Ran the Tesla branded pump (and integrated tyre goop) kit from the 12V socket without turning the car on (sitting in driver seat etc) - no issues inflating all four tyres with multiple stops and starts.
 
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Can someone help me or try this in their Model 3?

Monday morning I had low air in my tires so I figured I'll top off. I plugged in my portable air compressor (same 12 amp one I've used for years in my ICE car) and when I tried to use it, the "fuse" blew. I waited a few hours to reset and it blew again.

Next, when I sit in the car and step on the brake, I plugged it in and it worked...

So I figured I'll just step on the brake then go pump air, nope. It blew again...

The portable air compressor works when I'm sitting in the driver's seat, but the fuse blows when I get out and actually try to pump air into the car.

Next, I just tried a phone charger and it works no matter what. Probably due to lower amps?

Do we really need someone in the driver's seat to use the full power of the 12v socket?

I use a 12v tire pump just fine without being in the car.
 
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Thanks, will select one of those then. I was using a "Husky" and it would trip the breaker. Had to reboot to get it back.
Going on a small road trip and wanted something to keep the tires at optimum. The 12 volt connector might not be a bad thing to carry just in case anyway.

First trip driving distance without a spare tire. I worry more about that than running out of power.
 
I doubt the car is set up to cut off power at a lower current rate when you're not in it. Assuming the charging system works similarly to an ICE car, when the engine is running you'll be getting higher voltage from the 12v socket (roughly 13-15 volts) due to charging the 12v battery. The higher the volts, the fewer amps you need to do the same work (volts x amps = watts, or watts / volts = amps). So by not having the Tesla "running", the voltage would drop to 12.6 or so (battery voltage), which will then require more amps to run the compressor. Typically cigarette lighter sockets are fused at 10A on most newer cars.

Try using dog mode or something that'll keep everything on in the car and see if that helps.
 
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Has anyone tried the compressor that comes with the Tesla Tire Repair Kit - does that work well enough without blowing the 'fuse'?


Unfortunately, the air compressor that Tesla sells on their website will indeed trip the smart fuse on the 12V outlet on my 2020 M3

Also, that compressor is part of a repair kit that will not work on most M3 tires due to the fact that these tires contain acoustic foam.

So overall, really bad on Tesla...
 
I have the EPAuto which I've used at least a half dozen times to add air with no issues. But as others have noted, you can always get a 12V clamp extension to connect straight to the 12V battery, or you can get a foot pump. Those are going to be the most reliable.
https://www.amazon.com/gp/product/B01L9WSTEG/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

BTW this is the one I've owned since last September, use on my Model 3 and my husband's MS. Works great and has nice features. The flashlight beam is bright, I believe it comes with an extra fuse should you need one, and I like the auto shut off. The stand's legs keep it up off the ground and thinking help dissipate any heat generated. The Tesla Manual indicates that the power socket is suitable for accessories requiring up to 12A continuous draw (16A peak). Of important note -- as mentioned by someone else don't forget to power on the car before trying to use the socket, car's silent so you might forget this. I'm careful to follow the hook up directions as directed and never had a problem.

This product above is 12VDC, 10 to 15 amps, 120 to 180W. A lot of the tire air compressors I saw on line didn't list any of the specs so be careful ordering just anything. I felt the 10-15 amp range was safely within Tesla's 16A peak range.

This comes with a nice nylon fabric zippered carrying case, I keep the extra adapters and needles in a ziplock bag inside, along with the instructions for anyone unfamiliar with how to use it. Never know when you might run over a nail and get a slow leak and it's nice to have a 12V DC tire air compressor with you in that case so you can get to a tire repair shop or make it back home without ruining your wheels.
 
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It’s pricey, but I have this one:


In testing, it has not tripped the fuse. It can also be powered by battery, and I happen to have several of the DeWALT batteries. I keep one in the trunk with the air compressor, and change it out every quarter with a freshly charged battery, just in case.

I think Ryobi makes something similar and cheaper too. But, I went with DeWALT since I already have several of their tools and batteries.
 
I think Ryobi makes something similar and cheaper too. But, I went with DeWALT since I already have several of their tools and batteries.
Yup, the P747. I picked one up several months ago from Home Depot for $35. Can't remember the details why it was so cheap but it was brand new in box. I haven't used it too much but it is nice to not deal with a long power cord. Much like you, I have a bunch of Ryobi gear (tools, batteries and chargers).
 
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I doubt the car is set up to cut off power at a lower current rate when you're not in it. Assuming the charging system works similarly to an ICE car, when the engine is running you'll be getting higher voltage from the 12v socket (roughly 13-15 volts) due to charging the 12v battery. The higher the volts, the fewer amps you need to do the same work (volts x amps = watts, or watts / volts = amps). So by not having the Tesla "running", the voltage would drop to 12.6 or so (battery voltage), which will then require more amps to run the compressor. Typically cigarette lighter sockets are fused at 10A on most newer cars.

Try using dog mode or something that'll keep everything on in the car and see if that helps.
Exactly.
Unfortunately, the air compressor that Tesla sells on their website will indeed trip the smart fuse on the 12V outlet on my 2020 M3

Also, that compressor is part of a repair kit that will not work on most M3 tires due to the fact that these tires contain acoustic foam.

So overall, really bad on Tesla...
See the above quoted post.

When the car is awake, the DC/DC convertor powers the 12 volt system, not the 12v battery, and it does so at about 14.2 volts. That's 18% more voltage. Actually, it's probably more like a 20% boost in voltage, as the battery voltage will start to sag as soon as you put the load of the compressor on it.

Both of my portable 12v air compressors will trip my Model 3's 12v plug if the car is asleep, but if the car is awake (I just use Dog Mode on the AC), the extra voltage supplied by the DC/DC convertor (rather than the 12v battery) is enough to prevent the plug protection from tripping.

If you are having trouble with your 12v compressor tripping the protection on the 12v plug, keep your car awake and try again.

Let's say you're using a 150 watt air compressor, and let's say (unrealistically) that your battery doesn't sag. 12v X 12.5a = 150 watts. So you'd need to pull 12.5 amps. Now let's use the DC/DC convertor at 14.2 volts: 14.2v X 10.56a = 150 watts. So now you're pulling nearly 20% less current (10.56 amps) to get the 150 watts needed.

In reality, it's an even greater difference, as your battery voltage will drop when the compressor puts a load on it. How much it sags depends on the health of your battery and the amount of load of the compressor.

This isn't a blanket solution for *all* compressors, as it depends on how much current each compressor pulls. But it will at least allow some that are borderline to work.