Strange Battery Level - jump in charge level overnight w/o charging

[ChrisJ]

I had a strange battery/charging session thing happen two days ago.

I charged up the other night at a Supercharger close to my destination. Set the level to 90% and got 210 miles total by the time I left. I drove to my destination, leaving approximately 204 on the battery when I parked up for the night. But the next morning it had jumped to 219.

TeslaFi.com verifies all the data points.

Model S 70D, with the limited 75kW battery. I have not enabled the bigger battery option

Any idea or has anyone else seen phantom charge added in the middle of the night?

 

[mal_tsla]

With lithium ion batteries, the charge % is always an estimate. I imagine the car observed values that led it to believe the charge was higher than it thought it was before. Maybe the battery was warm and after it cooled it read a little higher.

No telling what the "actual" charge is (whatever that even means). The only way to know for sure how many miles remain is to drive until it stops.

 

[ChrisJ]

If it was temperature, then it was quite the jump. Almost a 5%.

And to add, this is not the "instant" vs "average" range. The reporting of my charge level has been consistent for the last 12 months, apart from a slight drop in the first few months - as is usual. I've never had the level suddenly jump like this. Typically the trend is down not up, right?

I really think there was some software glitch that charged the battery much higher and under-reported.

 

[Zaphod]

I guess the charging fairy stopped by and gave you some bonus electrons. Either that or your car has become self-aware and went on a joyride and "filled" back up hoping you wouldn't notice and it charged up too much.

Or maybe software glitch

 

[ChrisJ]

Yeah I was shocked it jumped 15 miles overnight - and at first I thought the wife may have plugged it in LOL

 

[gabeincal]

That's crazy........

 

[ChrisJ]

Someone else suggested it may be the pack rebalancing. I had set the max to 100% but stopped at 90%. But maybe it went a little higher and tripped the rebalance? Does that happen even after it's unplugged?

 

[Electric700]

Someone else suggested it may be the pack rebalancing. I had set the max to 100% but stopped at 90%. But maybe it went a little higher and tripped the rebalance? Does that happen even after it's unplugged?

Your car may be set to Ideal for the range display, so you may want to set it to Rated instead. Also I think that battery balancing only occurs when charging and the battery is at 93% or higher.

 

[Adri]

Balancing seems to happen only if the charge level is 93% or higher and AFTER charging has finished.

 

[ChrisJ]

Your car may be set to Ideal for the range display, so you may want to set it to Rated instead. Also I think that battery balancing only occurs when charging and the battery is at 93% or higher.

Nope definitely not ideal set.

 

[No2DinosaurFuel]

I have seen this happened to my s 90d twice since ownership.

I suspect it is some calibration the car is doing. I wouldn't worry about it.