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Discussion Starter #1
Has anyone used OBD to get a table of cell Voltages (in the 3 to 4 V range I imagine) vs charge percentage using the slider to set various target charges?

If so I'd really appreciate seeing the relationship.

Thanks!
 

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I've seen multiple graphs for that on various sites with respect to lithium ion batteries in general: voltage vs charge. But I've not seen it specifically for the Bolt. Here's just a random one as an example:


The biggest problem with getting an accurate SOC vs voltage is that long nearly-flat area of the curve and the fact that various cell types and capacities have slightly different curves... and different curves for charging vs open-circuit voltages.

Mike
 

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Has anyone used OBD to get a table of cell Voltages (in the 3 to 4 V range I imagine) vs charge percentage using the slider to set various target charges?
We have a 2017, so can only set to 100%, and 18 bars/hilltop/87-89%. But here are some average cell voltage readings at various SoC/bars I have captured from Torque Pro. I didn't capture these with any specific test in mind. Most are the average of more than one reading. They were captured at various states at random...during driving, charging, and at rest, so may vary a bit from reading only after a charge at rest, but will give some idea of average cell voltage at various bars.

20 bars 4.158 Telek has done extensive readings, and says the average cell voltage at end of charge rest is 4.167 volts. I have seen that number at least once in ours for sure.
18 bars 4.048
16 bars 3.984
14 bars 3.949
13 bars 3.749
10 bars 3.659
7 bars 3.587
6 bars 3.578
4 bars 3.534
3 bars 3.484
1 bar 3.305 My lowest cell read 3.241 volts. Only one reading, at 1.6% SoC...basically no bars

Here are gallen's readings from really empty:

 

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Discussion Starter #4
Great, thanks!. These are helpful. My goal was to establish a target charge level that left the cells at or below 4.00 Volts. Looks like around 17 bars. I can experiment and find what target percentage puts me there...I'm guessing 80 or 85% would probably do the job.

I think if the cells are rarely charged above 4.00V the battery will last very well.
 

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I have mine set to stop charging at 80% but for whatever reason, that always turns out to be 83% SOC reported. At 83% SOC (when the charger shuts off with it set to stop at 80% on the display), the cell voltage is between 3.97 and 3.98v.

Mike
 
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