Pre-Conditioning kWh Usage

[jsurpless]

Could someone provide me with how much power my 2020 M3 uses to pre-condition?

I'm curious because it seems to me that I'm using a lot of power when pre-conditioning the car.

Not necessarily saying that there's something wrong, just that it seems like a lot to me. Maybe I'm doing it too long?

The other day I pre-conditioned for 41 min (TeslaFi) when it was 41F and it used 3.85 kWh (7% battery). Today it was a similar temp and I only did it for 6 min, using 0.68 kWh (1% battery). Not sure if today I did it long enough.

Thoughts? Many thanks in advance!

 

[leonar40]

There are a lot of variables such as how high you have the climate control, which if any heated seats you have turned on, etc. Those values don't seem crazy to me. I usually only pre-condition at home when plugged in but if it's really cold out and I pre-condition before going home for work I try to limit it to about 15 mins, just enough to take the chill out of the cabin. It's a great feature of our cars, but yes it does take electricity to do it.

 

[Rocky_H]

Not necessarily saying that there's something wrong, just that it seems like a lot to me. Maybe I'm doing it too long?

How about 0 minutes? Yes, preconditioning is just wasting a lot of energy. If you want a warm cabin, that can be done in less than 5 minutes.

 

[jrweiss98020]

What is your purpose in preconditioning? If you have to go to a Supercharger and want minimum time there, or you need maximum regen braking right out of the parking lot (live at the top of a hill?), maybe 20-30 minutes is necessary. If all you want to do is warm up the cabin, I agree with Rocky that 5 min will get it into a comfort zone.

 

[GtiMart]

There are two important aspects. First, preconditioning heats the cabin, that's the obvious part. Your ptc heater can pull something like 6kW peak although it will stabilize after a few minutes to 1-3kW I think, depending on temperature.
The other aspect is that the car will also heat the battery until it gets close to 20C(70F). An SR+ with one motor will pull an additional 3-3.5kW to generate heat (in the motor circuitry) and circulate through the battery. A dual motor will go up to 7kW. Batteries are a huge mass and take time to heat up. Advantage of heating it: get all your power, get your regen available.
No, there is no way to heat the cabin from the app without heating the battery.
Is it worth it? For long drives probably as the car is more efficient. For short trips, no, it's a waste of energy. Up to you te decide what to do. I typically preheat max 5min before I leave unless I do a long trip.
3.85kWh in 41 min seems low/reasonable to me, you probably have an SR+ and it wasn't really cold (41F isn't even freezing)

 

[justsomeguy]

Probably don't need to precondition anywhere near 41 mins. I've never had the cabin take more than 15 minutes (probably even less tbh) to get up to temp from below freezing, and unless you're doing it to melt snow it's probably just wasting energy.

Preconditioning the battery for increased regen is in most circumstances going to be a net negative energy wise, with some obvious exceptions being if you're starting your trip on a decently long and/or steep decline.

 

[Gasaraki]

Could someone provide me with how much power my 2020 M3 uses to pre-condition?

I'm curious because it seems to me that I'm using a lot of power when pre-conditioning the car.

Not necessarily saying that there's something wrong, just that it seems like a lot to me. Maybe I'm doing it too long?

The other day I pre-conditioned for 41 min (TeslaFi) when it was 41F and it used 3.85 kWh (7% battery). Today it was a similar temp and I only did it for 6 min, using 0.68 kWh (1% battery). Not sure if today I did it long enough.

Thoughts? Many thanks in advance!

Why would you preheat for 41 mins? It's obvious that the longer you preheat, the more power it uses...
You preheat to warm up the cabin, which should take 5 mins. If you need to melt snow then longer but obviously it would use more battery.

 

[jsurpless]

Why would you preheat for 41 mins? It's obvious that the longer you preheat, the more power it uses...
You preheat to warm up the cabin, which should take 5 mins. If you need to melt snow then longer but obviously it would use more battery.

Only because I believe that Tesla recommends that in the manual. Could be mistaken, though

 

[jjrandorin]

Only because I believe that Tesla recommends that in the manual. Could be mistaken, though

Only if you are about to leave on a trip or something (and really, plugged into charging) to get the battery temp up for your long trip using energy from the wall.

Otherwise, its mostly for human comfort (warm cabin).

There isnt any real reason to pre condition when NOT plugged into charging more than the time it takes to heat the cabin to a comfortable level, which is not anywhere near 40 minutes, basically at any time.

 

[jsurpless]

Only if you are about to leave on a trip or something (and really, plugged into charging) to get the battery temp up for your long trip using energy from the wall.

Otherwise, its mostly for human comfort (warm cabin).

There isnt any real reason to pre condition when NOT plugged into charging more than the time it takes to heat the cabin to a comfortable level, which is not anywhere near 40 minutes, basically at any time.

What about that 'snowflake' icon that shows up on the climate screen of the app?

 

[jjrandorin]

What about that 'snowflake' icon that shows up on the climate screen of the app?

That tells you the battery is cold, but you can still drive. It will warm up on its own by you driving. Your max range is reduced when the battery is cold, but if you are actually driving any distance it will warm up while you drive. If you arent driving any real distance, it doesnt matter that the battery is cold, unless you are about to take it auto crossing or attempt to set 0-60 times.

 

[Phlier]

If you are going on a short trip, where the battery won't have time to heat up to normal operating temperature, than what everyone has posted about it being a waste of energy is true.

However, if you are going on a long road trip, the car is going to heat the battery up to normal operating temperature. If you pre-heat it before leaving on your trip, you'll take less of a range hit. This is because as you drive, the car will be generating heat to warm the battery. This energy could have been used for forward motion, had you pre-warmed the battery before leaving.

So for a long road trip, you aren't wasting energy by pre-warming the battery; that energy would have been used to warm the battery up during the trip anyway. The difference is that you're paying the energy cost to warm the battery up front if you pre-warm the battery while you're still hooked up to your home charger, vs taking a range hit and having stored battery energy do it along the way.

 

[jrweiss98020]

Your home electricity is likely cheaper than electricity you'll buy on the road, too.

 

[jjrandorin]

If you are going on a short trip, where the battery won't have time to heat up to normal operating temperature, than what everyone has posted about it being a waste of energy is true.

However, if you are going on a long road trip, the car is going to heat the battery up to normal operating temperature. If you pre-heat it before leaving on your trip, you'll take less of a range hit. This is because as you drive, the car will be generating heat to warm the battery. This energy could have been used for forward motion, had you pre-warmed the battery before leaving.

So for a long road trip, you aren't wasting energy by pre-warming the battery; that energy would have been used to warm the battery up during the trip anyway. The difference is that you're paying the energy cost to warm the battery up front if you pre-warm the battery while you're still hooked up to your home charger, vs taking a range hit and having stored battery energy do it along the way.

Provided you are doing it while plugged in. I have seen posts from people who are not plugged in, yet pre conditioning for supposed range, and that isnt going to work.

 

[jsurpless]

Provided you are doing it while plugged in. I have seen posts from people who are not plugged in, yet pre conditioning for supposed range, and that isnt going to work.

That's what I was doing, although not for range, just cause I thought that it "made the battery work better"

 

[Phlier]

I thought that it "made the battery work better"

It does. A battery that is turning chemical energy into electrical energy does so most efficiently if it is within a certain temperature range.

 

[Phlier]

Provided you are doing it while plugged in. I have seen posts from people who are not plugged in, yet pre conditioning for supposed range, and that isnt going to work.

I did put that in the last paragraph, but people don't usually get that far when reading my posts.

 

[Rottenapplr]

wow I don't really see the need for pre-conditioning unless its extremely cold with snow on the car. Otherwise the car heats pretty quickly to warm the cabin and the seat. Even when I travel in Arizona in the grand canyon and in wyoming where it was 25+ preconditioning for more than 3 mins is overkill.

 

[zef2021]

Could someone provide me with how much power my 2020 M3 uses to pre-condition?

I'm curious because it seems to me that I'm using a lot of power when pre-conditioning the car.

Not necessarily saying that there's something wrong, just that it seems like a lot to me. Maybe I'm doing it too long?

The other day I pre-conditioned for 41 min (TeslaFi) when it was 41F and it used 3.85 kWh (7% battery). Today it was a similar temp and I only did it for 6 min, using 0.68 kWh (1% battery). Not sure if today I did it long enough.

Thoughts? Many thanks in advance!

Hello. Pre-heating consumption it also depends on what was the state of the car, more important the battery before activating the pre-heating. Check out a recent video I release confirming that when the car is "awake" is also keep on warming the battery. Having said that, if you activate pre-heating when battery is already at let's say +15C it makes a difference comparing with -6C.

On the second video, I measured how much energy the car will take to warm up the battery from +3C to approx. +17C

Note, my car is 2021 M3 with heat pump yet, I hope you still find this interesting.

 

[Shelburne]

Thanks for the great info. I've only had my M3 LR since September. This has been a cold winter where I live and I frequently warmed the car for about 40 minutes before rather short trips, thinking it would help to extend the life of the battery. I see now that I was wrong. This new info will probably save me some $$ next winter