So I have to take a road trip in an EV, and it’s winter. So I’m going to have to use the AC. I know in my old ICE car I could have the AC off and the fan would blow hot air just from the engine. With my EV it seems to be the same, even with the AC button off the vents are blowing hot air. Is that hot air just heat vented from the battery? Or is it still using battery power for the compressor to heat the air.
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Teslas use a combination of energy transfer via heat pump from motor heating, and PTC heater (the defrost heat). Up to 15kW can be consumed for rapid heating of cabin, rear window and windshield. It’s awesome.
Some scavenge heat from the motors and batteries, probably not happening that much in winter. All have at least a resistive heating element as far as I can tell. The newer ones usually have/can be optioned to have a heat pump.
Set the temp leave it in full auto. The car knows when to run and not run the compressor or anything else based on temps. Just because then AC mode is on doesn’t mean the car is running it full bore when it’s below freezing. No you’re not hurting anything.
Energy from the battery is used to heat the air, be it with a heat pump or resistive heating. EVs are very efficient and don’t produce a lot of waste heat (comparatively) as a byproduct of driving.
It really depends on your model. The BMW i3 for instance has a heat pump and a resistance heater, but the range extender version only gets the resistance heater.
My Bolt has a resistive heater like you’d plug in to warm up a room. I’ve watched it use energy via Torque and I’ve seen it up to 3.5 or 4 kW. I preheat my car while it’s plugged in before I leave for work. It uses the heater settings it had when I last turned the car off.
Other cars have a heat pump and use waste heat from other systems.
With the temperature at like 45F the other day, my Bolt’s transmission coolant reached about 110F while driving and the battery was in the 40s-50s. It would be a pretty slow warm up if all I had was a heat pump (but I just have the resistive heater instead).
I have a model 3 with heat pump. It took 6 minutes yesterday to heat my car from 43° to 69°
I can’t explain why it blows warm air with the heat off, but if you need heat heat it needs to make some. Some cars are very inefficient in doing so (older Teslas for example) some use a heat pump and are much more efficient.
Using the seat heater is more efficient.
Also batteries aren’t as efficient in cold weather either so your range will be decreased.
a model number would be required to properly answer. but some have heat pumps (most newer ones) that do the trick. older ones not so much.
MODEL NEW 500 MONOTRIM 3+1 320KM /AM00 GS 42KWH
I love my instant on heat pump.
Amazing that you asked a technical question but yet you didn’t tell us the name and the model of your EV. I suspect something is wrong here. Perhaps even a BS question…
Why assume it’s a “BS” question?
Unless you’re an EV nerd like most of us here, it’s pretty natural to assume all EVs would have a similar system, just as (virtually) all gas cars have a similar heating system; they all have a heater core that engine coolant gets diverted to, and a fan to blow the heated air into in the cabin. The heater in a 2023 Toyota Corolla isn’t really that different than one in a 1957 Chevy.
The fact that EVs use a few different systems (or a combination of them) really shows how early in the transition we are- manufacturers haven’t really settled on one “best practice” yet.
Depends on the ev and the evs trim package. Our ev6 uses a resistance heater for initial heat the swaps over to a heat pump that sources it’s heat from the battery pack, motors and other electronics for heat. Newer Teslas use only a heat pump. Older Teslas use resistive heat only. Some cats only had resistance heat some heat a coolant loop then it goes through a heater core.
Why would you make a post like this and not mention what kind of EV you have?
Yes, they have a patent on that, they describe it as intentionally using the motor inefficiently.
I wonder if they can use that and the heat pump for dynamic brakes. (Regen but without the ability to put it in the battery, because it’s full).
I just saw a video from Tesla on their heat pump for cabin heating. As always, they found a way to reduce the number of parts while making the device more efficient. They have some good engineers on staff!
I have been considering a Ford E transit, and wonder how the heating is in that vehicle? Did they just cheap out and use a resistive heater ? If so, that would sure cut the range in the winter. I would have to consider bringing along a portable power pack in the back of the van and run a resistance room heater instead.