Battery only charge to 89%

[juli1]

When I charge my Model Y over the last few days, I charge always to 90% and when I entered the car, it was showing 89% after exiting the parking lot.

Now, when I charge the car and set the charge to 90%, the car only charge to 89%

If I try to charge at 100%, the app shows only 99% max.

I have read online old posts that explain this is about calibration, other about battery degradation. Most of these posts are from Model S and Model X owners.

Did anybody had this issue? If yes, did you get that solved?

 

[Zoomit]

It’s neither BMS miscalibration nor battery degradation. It’s simply the battery temperature changing. In this case falling after the charge cycle. Very, very common.

 

[rick245]

Yep, this happened to me. 90% was showing as 86% and 100% as 96%. But this was corrected during the charge.

 

[RedY23]

It’s neither BMS miscalibration nor battery degradation. It’s simply the battery temperature changing. In this case falling after the charge cycle. Very, very common.

I love this forum. Same issue and glad someone already answered it! Its cold in Michigan and it makes sense. But I would think if it charges to 90 then cools down would the computer not try to bring it to 90 again?

 

[Zoomit]

I love this forum. Same issue and glad someone already answered it! Its cold in Michigan and it makes sense. But I would think if it charges to 90 then cools down would the computer not try to bring it to 90 again?

Yes, the BMS will add more energy to the battery when it drops by 4%.

 

[RedY23]

Yes, the BMS will add more energy to the battery when it drops by 4%.

Today when my 5 day old MYP said charge complete, the car screen said 90% and my phone said 89%; there is definitely a glitch. LOL they should just lie and leave it at 90% for a few hours on all devices. Interesting though my miles stay at 270 when either at 89 or 90%... Such a non issue but gotta find something to be annoyed about in this perfect seemingly half IPhone(like) Half Machine work of perfection.

 

[GH77]

I charged mine at work on a 40a connection. Set the limit to 80%, came out to unplug at lunchtime and the car read 85%

 

[leoita]

Mine also charges to 89% when the limit is set to 90%.

 

[archae86]

To some extent it is guessing what percentage it has reached during charging. If the car sits for a few hours after charging in complete, with more measurement data in hand the BMS can refine the guess. On my cars I've seen the morning estimate once in a while be one or even two percent higher than the selected charge limit.

 

[GtiMart]

Percentage full is estimated using the cell voltages, and that doesn't change depending on temperature. The energy you can extract from that battery does change with temperature however. Even if you store 90% of the total capacity of the pack, when you extract energy you won't quite get 90, you'll probably get the equivalent of 89% in your particular case. So the car shows you that you can only get 89%. It's still charged to the voltage equivalent of 90% as you asked. There's no problem, it's normal, and would have a bigger difference if you lived in a colder climate.