Individual cell voltage drop - how much it too much?

[TB205gti]

Does anybody know what we should consider too high drop from a cell in the model S?

I do get quite a difference between max and min values under full throttle, and I do get limitations at times to the power (probably due to a cell dropping below 3V)

 

[JPoldo]

I'd like to respond to OP but have no idea how to measure cell voltage drop. Is there an app to do that? Avoiding any warranty violation, is it possible to connect my digital volt meter? Where is the test point?

 

[shred86]

You can read cell voltage from the CAN bus using an app like TM-Spy. It requires an OBD2 adapter with a bluetooth dongle. There's a couple threads on here about it if you search for TM-Spy. There's also Scan my Tesla for Android which shows more detailed information, although I haven't used it (iOS user).

As for the OP's question, I'm not entirely sure. I do notice the difference between max and min values across the cells will fluctuate quite a bit when you're accelerating/decelerating. Once you're idle, it seems to quickly fall back to within 5-10 mV of each other. I haven't tried logging the data during any full throttle acceleration yet. What state of charge are you doing this at?

 

[SilverSp33d3r]

View attachment 375100

I'd like to respond to OP but have no idea how to measure cell voltage drop. Is there an app to do that? Avoiding any warranty violation, is it possible to connect my digital volt meter? Where is the test point?

it looks like this...