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.