Battery balancing worked

[pleeau]

My X had 297 miles when new last September but had degraded to 274 miles recently. Seemed like a lot of degradation, so I wanted to see if balancing would work. The info on the forums seems a little old and unclear as to whether it works, so posting to confirm that.... IT DOES!

I drove to about 8% range and then supercharged. Once it hit 100%, it didn't stop but instead went into "calculating" mode. Charge was still flowing at 10kw. It flowed for a few minutes and then stepped down to 9kw. This continued for another 40 minutes until it stepped finally stepped down to 1kw (the supercharger was half empty so wasn't making anyone wait).

The range still displayed as 274 miles, but I drove about 7 miles very aggressively before it went down to 273 miles. Not sure when the displayed range calculation will update but it seems Iike there was about 10-14 miles of extra rated range in there. I'll try balancing it out a few more times this month to see if there's any more.

 

[TexasEV]

You’re going to risk degrading the battery more so you see a number displayed that you like better?

 

[pleeau]

1. Doesn't degrade if you use it right away. It's leaving it at 100% charge that is the problem.
2. It's not just the display. As my post indicates, there is actually extra charge going in to the battery. Your logic seems to be that in order to not 'degrade' the battery, you'd rather actually have the equivalent of a degraded battery (less range).

 

[P85_DA]

Nice job clogging that SC stall up ...really u could have done this at home not sure why folks have such an obsession with battery “degradation” when there is a lot of good data out there on the 186xx cells ..and the 100 batt is one of the best if not best pack Tesla has now

 

[jerry33]

If the X works the same as the S, the balancing circuits engage at 93%.

 

[pleeau]

Nice job clogging that SC stall up ...really u could have done this at home not sure why folks have such an obsession with battery “degradation” when there is a lot of good data out there on the 186xx cells ..and the 100 batt is one of the best if not best pack Tesla has now

8% degradation in a year seemed excessive so wanted to see if it was real degradation or not!

I did try balancing at home, but by the time I wake up, I don't know if it did any extra charging or not. It was good to be able to sit there and see it actually putting extra current in.

I had to go to LAX anyway, and with 8% charge left, wasn't going to make the 50 mile drive back home..

 

[gilscales]

Nice job clogging that SC stall up ...really u could have done this at home not sure why folks have such an obsession with battery “degradation” when there is a lot of good data out there on the 186xx cells ..and the 100 batt is one of the best if not best pack Tesla has now

the O.P. had stated (the supercharger was half empty so wasn't making anyone wait) try reading the entire post next time.

 

[pleeau]

If the X works the same as the S, the balancing circuits engage at 93%.

I don't know but it took another 40 minutes after being 100% full to "calculate" and put in extra charge so I don't see how it would be balancing before that.

 

[P85_DA]

the O.P. had stated (the supercharger was half empty so wasn't making anyone wait) try reading the entire post next time.

Where did I say I didn’t read entire post ? Try paying attention next time ...once he reached a 100% charge there was no need to continue charging ..complete waste of resources half empty or not

 

[jerry33]

I don't know but it took another 40 minutes after being 100% full to "calculate" and put in extra charge so I don't see how it would be balancing before that.

That often happens when the batteries are relatively new. The actual balancing takes place over a long period of time (a few days). It doesn't happen all at once.

 

[pleeau]

That often happens when the batteries are relatively new. The actual balancing takes place over a long period of time (a few days). It doesn't happen all at once.

ah, i usually only charge to 60%. so perhaps if I charge to around 95% at home more often it will balance. I don't like the idea of the car sitting there every morning at 100%...

 

[pleeau]

Where did I say I didn’t read entire post ? Try paying attention next time ...once he reached a 100% charge there was no need to continue charging ..complete waste of resources half empty or not

I took your first post as tongue-in-cheek, but not sure how charging beyond 100% is a waste of resources if it's drawing additional current that put in another 10 miles or so.

 

[gilscales]

Where did I say I didn’t read entire post ? Try paying attention next time ...once he reached a 100% charge there was no need to continue charging ..complete waste of resources half empty or not

because of your comment about clogging up the SC stall, I pay attention just fine, you on the other hand must have forgotten your post.

 

[acoste]

 

[Peteski]

ah, i usually only charge to 60%. so perhaps if I charge to around 95% at home more often it will balance. I don't like the idea of the car sitting there every morning at 100%...

I wouldn't worry about it. Just charge as and when you need to. If you actually need maximum range just charge it to 100% and let it balance for a little longer to get the most charge on board. The range number on the dash display is largely irrelevant and I just switched mine to percentage so I wouldn't have to obsess over it!

 

[unpollo2]

didnt the supercharger charge you a past the 15min fee after you hit 100%?

 

[Krazaak]

didnt the supercharger charge you a past the 15min fee after you hit 100%?

Idle fees start once your car stops charging, not at any specific percentage.

 

[TexasEV]

ah, i usually only charge to 60%. so perhaps if I charge to around 95% at home more often it will balance. I don't like the idea of the car sitting there every morning at 100%...

If you usually charge to 60% the battery meter will not give an accurate estimate of range. This has nothing to do with the battery being out of balance. Agree there is no reason for the car to sit at 100% every morning, but there's a big difference between charging to 60% and charging to 100%. If you charge to 90% routinely you will have an accurate display and the battery will be just fine.

 

[Krazaak]

I wouldn't worry about it. Just charge as and when you need to. If you actually need maximum range just charge it to 100% and let it balance for a little longer to get the most charge on board. The range number on the dash display is largely irrelevant and I just switched mine to percentage so I wouldn't have to obsess over it!

Sounds like a pretty useful piece of information to me. I wouldn't worry about it on a day to day basis, but I do a lot of long distance driving and it would be reason for concern for me if I saw a >20mi swing in my maximum range. Personally, I prefer rated miles view, because it gives two pieces of information instead of only one. You can visually see the state of charge (albeit less accurately) based on how full the icon is and you can see how many kWh the BMS thinks are in the battery based on the rated range. Showing percentage only gives one data point and it sounds like in the OPs case the battery was misreading capacity by several kWh. If I could switch the view to kWh instead of miles or percentage, I'd do that instead.

It would be helpful if the car also alerted you to excessive cell imbalance and suggested an overnight balancing charge to remedy it. My Zero SR app shows the cell imbalance value, which is pretty key to knowing if you're going to have an early battery shutdown as you get into the 10% or less range.

 

[Krazaak]

If you usually charge to 60% the battery meter will not give an accurate estimate of range. This has nothing to do with the battery being out of balance. Agree there is no reason for the car to sit at 100% every morning, but there's a big difference between charging to 60% and charging to 100%. If you charge to 90% routinely you will have an accurate display and the battery will be just fine.

That's my experience as well. I charge daily to 90% and over 26.5k miles I've experienced apparent degradation from 289 to 287 miles (at 100% charge).