Whats the largest Power Inverter you can use in a Tesla?

[Rawlings2019]

Correct, 12V is topped off from the HV.

I am converting a school bus into an RV. I have an LR Model 3. It would be amazing to get at least 1500 watts from the battery of the tesla to power our RV. I think 1500 watts would be enough to power a small AC or Mini Split. My Question, if I attach an inverter to the 12v battery on my tesla does the car keep it that 12v battery topped off as the power is drawn from the RV or is there a setting for me to keep the car on to keep that battery topped off?

 

[n2mb_racing]

I am converting a school bus into an RV. I have an LR Model 3. It would be amazing to get at least 1500 watts from the battery of the tesla to power our RV. I think 1500 watts would be enough to power a small AC or Mini Split. My Question, if I attach an inverter to the 12v battery on my tesla does the car keep it that 12v battery topped off as the power is drawn from the RV or is there a setting for me to keep the car on to keep that battery topped off?

It's charged all the time. But there are some warnings in the warranty about doing this. Tesla can likely see the extra 12V draw in the logs, and could deny warranty on the battery if you used it a lot. I don't think anyone has had that happen yet, but to be safe I'm only planning to use mine for backup power when the power goes out.

 

[dcp123]

I don't see how a direct quote from the text of the Tesla warranty has any uncertainty to it.

This isn't a 1985 Buick, it is a car with constant telemetry of exactly what the systems are doing at all times. If you think they can't show hours of 2kW load on the DC/DC converter and associate that to running an inverter in a way which voids the warranty on that part, you are mistaken.

I know this is an old thread, but people reading this should know that you simply ignored the most important part of that warranty exclusion.
It says that the warranty doesn't cover damage "caused by, due to or resulting from" the identified uses or misuses of the car. If you have any idea at all what you're doing, there's no reason whatsoever that installing an inverter for occasional use should cause the slightest bit of damage to the car. The warranty still applies to everything it would normally apply to, just nor damage caused by your use or misuse of the inverter.

Now, if you buy a Tesla and just drive if from a Supercharger to your off-grid cabin every day to power that cabin, you probably will wear out the high-voltage battery prematurely and Tesla will, quite rightly, tell you to go pound sand if you come whining that you want a new battery to replace the one you destroyed. But occasional use drawing well under the low-voltage battery's 600A capacity over the short-term and under the DC-DC charger's capacity over the medium term, shouldn't cause any damage unless you use inadequate wiring, don't use a fuse, buy a defective inverter that catches fire, etc.

Edited to add: Just for giggles, I checked an e-bay listing selling a Model S DC-DC converter. The converter is plainly labeled with a sticker indicating a maximum output of 2500W at 9-16VDC. That's a lot more than I expected, but probably only applies when the car is on and pumping coolant through the converter.

 

[PhysicsGuy]

They can just ask the car to connect the battery to the charger port, same as super charging. Then you get direct DC power for a high voltage inverter.

Easy and clean solution, but Tesla won't allow it outside of their use.

There may be a BMS issue with that. Depending on the BMS design, it may not be a good idea to draw power from the charging input leads.

 

[PhysicsGuy]

I know this is an old thread, but people reading this should know that you simply ignored the most important part of that warranty exclusion.
It says that the warranty doesn't cover damage "caused by, due to or resulting from" the identified uses or misuses of the car. If you have any idea at all what you're doing, there's no reason whatsoever that installing an inverter for occasional use should cause the slightest bit of damage to the car. The warranty still applies to everything it would normally apply to, just nor damage caused by your use or misuse of the inverter.

Now, if you buy a Tesla and just drive if from a Supercharger to your off-grid cabin every day to power that cabin, you probably will wear out the high-voltage battery prematurely and Tesla will, quite rightly, tell you to go pound sand if you come whining that you want a new battery to replace the one you destroyed. But occasional use drawing well under the low-voltage battery's 600A capacity over the short-term and under the DC-DC charger's capacity over the medium term, shouldn't cause any damage unless you use inadequate wiring, don't use a fuse, buy a defective inverter that catches fire, etc.

Edited to add: Just for giggles, I checked an e-bay listing selling a Model S DC-DC converter. The converter is plainly labeled with a sticker indicating a maximum output of 2500W at 9-16VDC. That's a lot more than I expected, but probably only applies when the car is on and pumping coolant through the converter.

Good points. I hope you are right. It seems really reasonable to try it to run a fridge and freezer during a power outage.