# Charge level increased while parked???



## Needsdecaf

Searched as I thought I had read something on this before but couldn't find anything.

Something really odd happened today. My charge status INCREASED while the car was parked. And not a little, but by 4% overall!

I was out at some projects this morning and was headed back into the office. It's cold here in Houston and I added extra charge this morning to compensate. So I was keeping an eye on the battery since this is the first real cold snap we've had since getting my M3P this spring (I previously owned a 2018 LRAWD from Dec 2018 to March 2020, so I have experience with these cars in cold weather, just not the performance). On the way back to the office I checked the battery level several times in the trip display as I wanted to see if I was "on target" for my estimated arrival battery percentage of 35%. At one point I was going pretty quickly and I dropped 1% below target but I slowed down and got it back to where it had been. Bottom line, I'm sure of what I'm about to say. Normally I probably wouldn't have been paying that much attention.

Before I left for lunch, I took a quick look at TeslaFi to see how I had used the battery this morning vs. typical trips I have done to this project site in warmer weather. Well imagine my surprise to see that my car was now reading 39% instead of 35%. At first I thought it was a TeslaFi error, but when I got to the car it indeed read 39%. Then I thought maybe driving to lunch and back would somehow "recalibrate" it back to 35%, but no, now my car is parked at 38%.

What gives?


----------



## garsh

Just the BMS adjusting its estimate of battery state of charge.


----------



## Wooloomooloo

Yes mine does this occasionally as well, it is partly the BMS re calibrating but is also affected by temperature changes, either ambient or from prior driving.


----------



## Needsdecaf

Wow, I'm just surprised that in nearly 50k miles of using TeslaFi I've never seen this before.


----------



## Wooloomooloo

Needsdecaf said:


> Wow, I'm just surprised that in nearly 50k miles of using TeslaFi I've never seen this before.


Do you check it every day? If you filter by parked and rated range, you will find an example I am sure.


----------



## Needsdecaf

Wooloomooloo said:


> Do you check it every day? If you filter by parked and rated range, you will find an example I am sure.


Not every day but quite often.

Filter which report?


----------



## Needsdecaf

Huh, ok, I did just filter that and I see it.

This car seems to always be off on charging. Often times I come out and it'll be 2, 3 and sometimes even 4 percent above my target. But looking at the charge data in TeslaFi, it is almost always stopping at the 80% or 85% goal.

Here is a good example. I had the charge set to 80%. And you can see the car stopped charging at 80%. In the morning, I decided to pre-condition the car and change my charge to 85% as I was going to have to go on a few extra legs. But as you can see, even though the night before the car shut off charging with 80%, in the morning it started with 83%. 

Is my BMS seemingly wonky? My old car wasn't like this....

Thanks all.


----------



## sduck

The new graph in teslafi really shows this off when it happens.


----------



## JWardell

Needsdecaf said:


> Huh, ok, I did just filter that and I see it.
> 
> This car seems to always be off on charging. Often times I come out and it'll be 2, 3 and sometimes even 4 percent above my target. But looking at the charge data in TeslaFi, it is almost always stopping at the 80% or 85% goal.
> 
> Here is a good example. I had the charge set to 80%. And you can see the car stopped charging at 80%. In the morning, I decided to pre-condition the car and change my charge to 85% as I was going to have to go on a few extra legs. But as you can see, even though the night before the car shut off charging with 80%, in the morning it started with 83%.
> 
> Is my BMS seemingly wonky? My old car wasn't like this....
> 
> Thanks all.


Most of the time you just don't notice it. How often do you scroll through the minute by minute logs in Teslafi and look for a range increase? Probably never (if you're not me). But they have always been doing this. It's the nature of how the BMS estimates your range/battery capacity. After a good drive where it has been watching power consumption, it needs the car to be sitting so voltage is stable in order to make new estimations.


----------

