"Charging Complete" SOC does not match Charging Limit

[solaficionado]

State of Charge does not match charging setting limit. Each time I attempt to set the charging limit to 70% it tells me charging is complete at 68%. I called Tesla service and they were not very helpful. Does anyone have any advice?

 

[ai4px]

My Bolt EV does something similar.... when using "hill top reserve" it should charge to 90%, most days it's at 88%.

 

[boaterva]

Have you tried ‘wiggling’ the limit setting to try to restart charging? I’ve seen this for 100% where it goes only to 97 but not really the same thing.

And, of course, have you rebooted? Often clears up wacky software things especially to do with charging. (Normal two scroll wheels should be sufficient.)

 

[nagypite]

Maybe your battery is just unbalanced. You can balance it at home.

 

[Darmie]

The numbers pulled from the CAN Buss with TMSPY is never the same from what the car displays. I feel these are just estimates anyway. The other thing I'll note is that I try my best to attempt to set the charging limit with the app but always find looking at TESLAFI that it's never just exact. So, I started to use TESLAFI to set my charge limits. I went one step further and use their scheduler to set charge limits. 90 on Thursday evenings and back to 70 Sunday nights. This helps not to forget if we are doing anything Friday or the weekend and ensures I don't forget to reset for normal work driving through the week.

 

[solaficionado]

Have you tried ‘wiggling’ the limit setting to try to restart charging? I’ve seen this for 100% where it goes only to 97 but not really the same thing.

And, of course, have you rebooted? Often clears up wacky software things especially to do with charging. (Normal two scroll wheels should be sufficient.)

I did both. I wiggled the charging setting several times with the same effect, and also did two restarts of the MCU with no change. What did eventually work is charging to 80%, which occurred with SOC and the charging setting matching...

 

[boaterva]

So charging night worked? Hm.... no idea! Have to see how it goes!

 

[DriverOne]

Mine's been doing that lately... instead of stopping at 90% it'll go higher. I wonder if it's a software change, or that calibration changed since I'd been driving the batter to lower states of charge lately. I'm not worried about it.

 

[jboy210]

Battery SOC is not a precise measurement because it is hard to measure. It is an estimate made by the observing current flows and other characteristics. And these characteristics are effected by environmental factors, system load, etc Read this article if you want some basic information. And then google "Coulomb Counting" to go deeper.

The bottom line is the SOC is an estimate, don't get hung up on the exact numbers.

 

[Chickenlittle]

State of Charge does not match charging setting limit. Each time I attempt to set the charging limit to 70% it tells me charging is complete at 68%. I called Tesla service and they were not very helpful. Does anyone have any advice?

Consider therapy

 

[DCGOO]

Battery SOC is not a precise measurement because it is hard to measure. It is an estimate made by the observing current flows and other characteristics. And these characteristics are effected by environmental factors, system load, etc Read this article if you want some basic information. And then google "Coulomb Counting" to go deeper.

The bottom line is the SOC is an estimate, don't get hung up on the exact numbers.

I have had charge % actually increase AFTER charging stopped and driving away. If you want to land at 70%, set your charge limit to 73%. As jboy mentioned, it is not particularly precise. At least you are working with %. It is way worse if you worry about miles!