2023 M3 RWD Scheduled Charging to 100% Issue or Normal?

[baddiebats]

I set my new 2023 RWD to 100% charge limit, with scheduled departure and off peak time to 7:45 AM. However it's not reaching 100% for another 45 minutes past the designated time. Is this normal, or should it get better over time? My MYLR is set to 70% with similar scheduled depature and off peak and is always done around or before, never past.

Both cars are outside along with my Tesla WC. I'm in NJ, so not sure if overnight winter temps are a factor with the LFP pack. This is only the 3rd charge on the car, all at home, and all have gone 45 minutes past.

Here's screens from this morning.

 

[DuncanM]

I would turn on the battery preconditioning, as LFP batteries won't charge well when cold.

 

[jjrandorin]

Is this normal, or should it get better over time?

Its normal for the car to sometimes balance cells when charged to 100%

Here is another thread asking about charging to 100% that has responses you can read through:

99% Issue - Calculating [Charging to 100% hangs at 99%]

Hi if anyone can help, i’m having a issue, when i charge it, It will go to 99% & just hang there & changes to calibrating or calculating. The moment i click stop charging it then shows 100%. If anyone can help that would be grate. I been to tesla 2 times, 1 they checked over the battery & said...

teslamotorsclub.com

 

[baddiebats]

I would turn on the battery preconditioning, as LFP batteries won't charge well when cold.

I assumed its a cold weather thing with LFPs. Lows have been in the 30s since I got the car.

Its normal for the car to sometimes balance cells when charged to 100%

Here is another thread asking about charging to 100% that has responses you can read through:

99% Issue - Calculating [Charging to 100% hangs at 99%]

Hi if anyone can help, i’m having a issue, when i charge it, It will go to 99% & just hang there & changes to calibrating or calculating. The moment i click stop charging it then shows 100%. If anyone can help that would be grate. I been to tesla 2 times, 1 they checked over the battery & said...

teslamotorsclub.com

Thanks for the thread. The charging to 100% appears to be linear and the time estimate was pretty close. I departed at 8:30 with 99% per app, 100% per car. Probably 99% since I had regen.

 

[E90alex]

What was the SOC when you started charging and what time did you plug in?

 

[baddiebats]

What was the SOC when you started charging and what time did you plug in?

About 20%, plugged in night before at 730PM

 

[E90alex]

About 20%, plugged in night before at 730PM

That should be more than enough time I would think. So mostly likely just temperature issue. The battery is getting cold as it sits and when it starts to charge in the middle of the night it’s colder than it accounted for.

I guess just set the off peak end to like 1.5 hours sooner so it can finish before you actually need it. And adjust as needed as it (hopefully) improves as it gets warmer.

 

[AlanSubie4Life]

Its normal for the car to sometimes balance cells when charged to 100%

He isn’t even close though.

Probably just a frozen pack not correctly accounted for I guess. Or just a bug.

If it goes away when it is warm it is probably just the cold resulting in a delay in the start of charging as others have said. (Once charging starts the temp should have minimal effect.)

Should not be an issue if nighttime temps remain comfortably above freezing.

 

[PearlModelS]

Try turning off-peak hours off.

You may have a conflict and charging is starting too late to get 100% by 8am.

 

[byeLT4]

Since you are asking the 3 to charge to 100 vs the Y's 70, are you giving it enough time using off peak charging?

 

[ATPMSD]

Here is what is likely happening.

With scheduled departure, when you plug in your car it will charge for a short period of time. This is so it can determine the charge rate, and then it stops. Normally, the car then starts charging based on the SOC of the car, the desired SOC, and the calculated rate of charge. Normally, this works and all is good.

But this does not take into account a cold battery or weather into account. When the car starts charging not all of the charging it determined would be available, is available! Most of it goes to the battery but some of the power goes to warming, then keeping the battery warm while charging. Therefore, the start time calculation is wrong. The solution is, as you have stated, just push the departure time back.

 

[Jsch223]

new to my m3 rwd. Picked up a week ago. My guess is that it’s due to your off peak setting. I notice that when I charge to 100% the last 10% takes over 1.5 hours. I would bet you don’t have enough time to top off.

 

[baddiebats]

Update: Last night I charged from 23% to 100% with off peak changed to 6:45 instead of 7:45. It reached 90% by 6:45 and 99% by 7:35. The final 1% took the longest at about 30-40 mins with the WC reducing amps.