"Normal" cell imbalance for high load (Scan My Tesla data)

[insaneoctane]

Just curious how much cell imbalance people see when they accelerate quickly? My cell imbalance starts out around 2mv to 6mv when leisurely cruising, but jumps pretty high during moments of heavy 'throttle'. Theoretically this doesn't hurt my head, but was wondering how high imbalance people have seen and within what range is "normal". Here's a plot of my imbalance I just made of a couple squeezes of the accelerator....

 

[Tessaract]

Although, I haven't monitored cell imbalance on my car, the cell imbalance under acceleration is possibly caused by increased resistive voltage drop imbalance in the connections to the cells when heavy current is drawn from the batter, and not in the cells themselves. The resistive imbalance cannot be seen under low/no acceleration because of the lower current drawn.

 

[ElectricIAC]

Just curious how much cell imbalance people see when they accelerate quickly? My cell imbalance starts out around 2mv to 6mv when leisurely cruising, but jumps pretty high during moments of heavy 'throttle'. Theoretically this doesn't hurt my head, but was wondering how high imbalance people have seen and within what range is "normal". Here's a plot of my imbalance I just made of a couple squeezes of the accelerator....
View attachment 514007

How’d you get that?

 

[insaneoctane]

How’d you get that?

Search "scan my Tesla" app (here). Requires some hardware too

 

[Tessaract]

Although, I haven't monitored cell imbalance on my car, the cell imbalance under acceleration is possibly caused by increased resistive voltage drop imbalance in the connections to the cells when heavy current is drawn from the batter, and not in the cells themselves. The resistive imbalance cannot be seen under low/no acceleration because of the lower current drawn.

I don't get how someone thinks this post is funny. If they don't need more explanation wrt the equivalent circuit underlying this electric analysis, go ahead and ask. I'm happy to explain more details.

 

[MP3Mike]

Just curious how much cell imbalance people see when they accelerate quickly? My cell imbalance starts out around 2mv to 6mv when leisurely cruising, but jumps pretty high during moments of heavy 'throttle'. Theoretically this doesn't hurt my head, but was wondering how high imbalance people have seen and within what range is "normal". Here's a plot of my imbalance I just made of a couple squeezes of the accelerator....

You can't accurately measure the cell imbalance while under a load, as all of the cells aren't measured at the same time; it cycles through them. (I suppose if you could keep the load 100% consistent for a few seconds you might be able to get a good reading.)

 

[insaneoctane]

You can't accurately measure the cell imbalance while under a load, as all of the cells aren't measured at the same time; it cycles through them. (I suppose if you could keep the load 100% consistent for a few seconds you might be able to get a good reading.)

Interesting. Reference for this information?

 

[EvanLin]

Search "scan my Tesla" app (here). Requires some hardware too

Thanks for sharing the imbalance info.
I knew how SMT works as an app, but how do you make the data to a chart?

 

[insaneoctane]

Thanks for sharing the imbalance info.
I knew how SMT works as an app, but how do you make the data to a chart?

Just dropped the data into Excel and pivot table/graph to see it.

 

[ord3r]

Interesting. Reference for this information?

There's some leaked internal documentation floating around, doesn't state this directly, but based on the number of Batman and Robin chips , the number of voltage channels each chip can sense, and the number of cells, MP3Mike's statement sounds reasonable.