Does SOC need to be 90% for the BMS to balance cells?

[laservet]

Read it somewhere, don't remember where. I currently charge to 85% but will charge to 90% periodically if needed.

 

[gaswalla]

it used to be that way back in 2012/13 (actually I think it was 93%). According to the well known hacksters and battery tinkering folks, it appears to rebalance at any SOC now..

 

[laservet]

Thank you. I’ll stick with 85%.

 

[MikeBur]

it used to be that way back in 2012/13 (actually I think it was 93%). According to the well known hacksters and battery tinkering folks, it appears to rebalance at any SOC now..

Not aware there was ever a magic number, even back then, though stranger things have happened

Perhaps this was the estimation engine threshold. There’s no magic number now for that though. The reason why it is recommended to be higher occasionally is to get the widest variance from start charge to end charge to feed into the battery estimation model. Many small variance charges causes estimation to drift over time.


Btw This graph shows balancing in last few frame of animation I created at 91.5%, pure geekdom
Chassis CAN Logging To ASCII Text Plus Graphing

 

[laservet]

Not aware there was ever a magic number, even back then, though stranger things have happened

Perhaps this was the estimation engine threshold. There’s no magic number now for that though. The reason why it is recommended to be higher occasionally is to get the widest variance from start charge to end charge to feed into the battery estimation model. Many small variance charges causes estimation to drift over time.


Btw This graph shows balancing in last few frame of animation I created at 91.5%, pure geekdom
Chassis CAN Logging To ASCII Text Plus Graphing

VERY interesting info you've provided in the link. Does accuracy of the battery estimation also depend on discharging it way down occasionally as well?

 

[MikeBur]

VERY interesting info you've provided in the link. Does accuracy of the battery estimation also depend on discharging it way down occasionally as well?

Thanks.

The larger the variance the more accurate the estimation model.

 

[wws]

Somewhere buried in this thread, it was claimed that balancing happens at 85+%:

How I Recovered Half of my Battery's Lost Capacity | Tesla Motors Club

 

[laservet]

Somewhere buried in this thread, it was claimed that balancing happens at 85+%:

How I Recovered Half of my Battery's Lost Capacity | Tesla Motors Club

Thank you.