Model 3 charging every night, even when I tell it not to?

[AlphaOneZero]

So bit of an issue with my 2021 M3 SR+, will take a bit of explaining:

My usual routine with the car is to leave it plugged in over night but not charge during the weekdays, the car preconditions for me to leave at 06:15 for work, and when I get to work i charge there. When i leave work with 100% (LFP so every thing I read says to charge to 100%) I arrive back home with approx 90%, and if I'm not doing anything else that evening I'll plug the car back in and because I have scheduled charging turned off, the car will start to charge, I cancel this and then my car stays at the same state and the following morning preconditions and I charge again at work...means i use less energy at home but still precondition using the wall box.

Now for the past few days my car will again start to charge when i plug it in back home, however even after cancelling this and with scheduled charging still turned off, it will still charge sometime during the night...I'm not sure if this is a bug with the preconditioning or how I can stop it doing this short of leaving the car unplugged unless I need to charge it and just precondition using the car battery instead? I have tried a car restart and the app is up to date, not sure what else to do. Anyone else having this issue?

 

[puckpurnell]

I don't know enough about the preconditioning or turning off the charging. But, I do know that keeping your Tesla at 90% or often charging to 100% is not a good idea, especially since you're only using 10% to get to work. The conventional wisdom is charge to 80%. Just say'in.

 

[Randy-12]

I don't know enough about the preconditioning or turning off the charging. But, I do know that keeping your Tesla at 90% or often charging to 100% is not a good idea, especially since you're only using 10% to get to work. The conventional wisdom is charge to 80%. Just say'in.

LFP different technology

 

[Grabthar]

The cars, if plugged in, use the wall current to help do battery maintenance - leveling the charge across the pack, etc. That might be what you're seeing?

 

[skygraff]

Set the charge level slider low and it shouldn't charge unless it drops below that point during the night. Should still use shore power for preconditioning.

When you are ready to charge, raise the slider to your desired level.

 

[DocHolliday]

If you really don't want it to charge overnight, leave it unplugged. Phantom drain and preconditioning in the a.m. won't use that much energy.

 

[AlphaOneZero]

Set the charge level slider low and it shouldn't charge unless it drops below that point during the night. Should still use shore power for preconditioning.

When you are ready to charge, raise the slider to your desired level.

I think I might have to, it's just another step to remember to do I guess even if it isn't a major inconvenience, wasn't something I've had to do previously since first owning the car so was hoping I was missing something obvious or it was a known bug

 

[AlphaOneZero]

If you really don't want it to charge overnight, leave it unplugged. Phantom drain and preconditioning in the a.m. won't use that much energy.

Yeah I thought about this, I'm not that bothered by the car using the battery to precondition, it's just not something I've had to consider before as I could leave it plugged in and the preconditioning/ scheduled charge would just work as intended.

It's just on those odd occasions I've had to do a last minute long distance trip and so would top up the battery at home before leaving and I could just start that from the app even if I wasn't at home there and then, leaving it unplugged just limits the flexibility of starting that, very narrow set of circumstances I know but annoying when it worked fine before but doesn't now.

 

[heavyD]

I have my car set to precondition in the a.m. only on weekdays but for whatever reason the car skips preconditioning at least one monday a month. I just equate it to software bugs.

 

[blackT3$!@]

I have scheduled charging set to start every night at 11:15pm. Occasionally when I plug it in during the day my 2021 3LR AWD will pull a couple kw's to the battery pack. Tesla knows best.

 

[skygraff]

I think I might have to, it's just another step to remember to do I guess even if it isn't a major inconvenience, wasn't something I've had to do previously since first owning the car so was hoping I was missing something obvious or it was a known bug

I don’t know why it’s suddenly changed behavior but, since you were already taking the step of canceling the charge after plugging in, I think the slider change step will probably be a wash. Instead of canceling after you’ve plugged in, move the slider before you plug in (will require an extra step sliding it back to 100 at work but less wear on the contactors so…).

You can even integrate the steps into your normal routine. If you access the app on your way to the car at work, the charge slider will be on the main screen and you can slide it down to 80 or 70 (or even a quick swipe down to minimum of 50). If you don’t access the app, just do the same on the MCU when you get in or while stopped at a light during your drive or when you get out at home. Reverse the process on your way to work.

Basically, the way it used to work seems like it wasn’t following the description in the manual (although, I never quite understood the way they described/handled precondition scheduling) but this technique will work every time. You can experiment after updates to see if it goes back to the way it used to be.