Why does my Model 3 almost always complete at 1% less than set charging limit?

[Speleodoc]

For example, if I set the charge limit at 70%, it almost always finishes charging at 69%, with a message that says “Charging completed at 10:00 pm with battery at 69%”. I tried balancing the battery cells by setting charge limit to 100% and letting it take its time (about 20 minutes) at 100% to complete fully charging (and then took it for a long drive a few minutes afterwards). I’ve tried other limits (50%, 60%, 65%, etc…), but it usually charges to 1% below those limit. I don’t think it has anything to do with estimated battery percentage, as I would think it would charge to the set limit, regardless of the BMS estimate. Any ideas as to why this is happening?

 

[jdcollins5]

I see this more in cold weather. I have just thought it had to do with temperature drop from the time it stops charging until a notification is sent to your app.

I do not see this much in warm weather.

 

[Speleodoc]

jdcollins5, you’re right. We’ve had a warm spell in central Illinois over the past couple of days and it’s been charging to the setpoint. Seems like it charges to the setpoint when ambient temp is > 50 degrees. Thank you!

 

[UncertainTimes]

Teslas prefer 69%

 

[Gyrolion]

Well because your battery is cold, it is 70% or mabey even 71/72, but only 69% is useable.

If you have an app like teslafi you can see the real % and the disaplayed cold %.
Right now mine is saying it is at 63% on the display but teslafi states that when it is heated up it will be 65% instead.

 

[ButchAZ]

What happens if you set it to charge to 71%?

 

[tbenitez12]

I’m having this problem too, but a little more severe. I’m in Southern Az and our avg temp right now is 65-75. But my car set to 60-61% and I wake up and it’s almost always set to 55-57%. Idk why

 

[tethlee]

I’m having this problem too, but a little more severe. I’m in Southern Az and our avg temp right now is 65-75. But my car set to 60-61% and I wake up and it’s almost always set to 55-57%. Idk why

My 15 MS is doing the same thing. I have it set to charge to 90% and I only goes to about 87-89%, and our weather here has warmed up, so it's not cooler weather as mentioned above, but warmer. Haven't been able to find a post with a reason or if this is something to be concerned about.

 

[RichAZ/CapeCod]

FWIW, I set my charge rate using the Tesla app. Seems to be more accurate than when setting it in the car.

Rich