Charged past the limit that i set

[Acousticmood]

Hello - I have my charging limit set at around 80%. Today when I picked my car up from the charger it had gone past that limit. Not by a lot but I am concerned about charging it to the maximum when not necessary.

Here is a screen shot. Has anyone else experienced this or can offer some advise?

Thanks,
George

 

[JGard]

This happens to me on an almost daily basis. Doesn't matter what I set my limit to, it regularly goes over by 2-3%

I noticed it happens more now that I use the scheduled charging feature and only charge once a day. When I used to just plug in my car all the time and let it keep topping off, this happened less. I work from home, so the car is plugged in quite often

 

[Acousticmood]

Thanks - I can liver with a couple %. Just didn’t want it to keep going

 

[brkaus]

I occasionally see the same thing. I've decided its due to the battery temp stabilizing overnight. Of course, I have no real clue.

I need to look for the TeslaFi data next time it does it. See if it's moving after the charging stops.

 

[Acousticmood]

If it only goes a few % I can live with it. I’ll find out in the morning

 

[w0ss]

My teslafi shows it stopping at the assigned percent. I have no idea what is actually happening.

Teslafi says charging stopped and I will check the app and it says 80%. I wake up in the morning and it's at 83% and there were no charging events.

 

[go2realize]

I observed this few times on my LR AWD. Usually what happens is, I start charging early morning when it is cold, it charges to 80% based on the set limit, I get a notification that it is done charging to 80%. Then few hours later, when the temperature gets warm outside, it shows it charged to 82 to 84%. I always assumed that the outside temperature is affecting the battery charging.

 

[Acousticmood]

Thanks all for the replies

 

[SigNC]

battery warms up, voltage goes up, percentage goes up.

 

[miimura]

I have our car set to charge to 80% overnight. When I check it in the morning, it will randomly be somewhere between 78% and 82%. Strangely, it is usually 78, 80, or 82, not the odd values between those.

 

[Geebao]

I’m guessing it’s due to imbalanced cells in the pack. The calculation determined for percentage can be off as it’s not calculated by each individual cell and instead the overall pack. The BMS will go through balancing the cells. Think of it like a gas car that is parked on a hill and the gas moves to one side of the tank and the sensor is on the opposite side of the tank. The sensor will read less, but as soon as the tank is leveled then it more accurately reads the correct percentage. I can also see it happen the other way around where it reads more and when it is level it actually reads a bit less. This may be less noticeable as one might thing something turned on and is fathom draining the battery.

 

[SigNC]

Can also happen where you charge to the set percentage at night when it's cool. Then later in the day the pack is warmed up from the sun or a hot garage, which bumps cell voltage and the BMS reads this as a higher charge percentage.