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Does anyone have a Bolt EV battery diagram that corresponds to the TorquePro PIDs?

Basically, I want to know where certain cell groups physically reside in the battery, and in particular, whether they are in the same module. Specifically, my cell groups 65 to 72 are all reading one one-hundredth of a V lower than the rest of the cell groups.
 

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Does anyone have a Bolt EV battery diagram that corresponds to the TorquePro PIDs?

Basically, I want to know where certain cell groups physically reside in the battery, and in particular, whether they are in the same module. Specifically, my cell groups 65 to 72 are all reading one one-hundredth of a V lower than the rest of the cell groups.

If the traction pack is anything at all like that of the 2001 RAV4-EV, there might be certain cell groups that are less exposed to the temperature control system. (It was forced air ventilation in the RAV.) On the RAV4, the result was that there was a consistent cell group location in many vehicles that showed degradation before others. Some owners were known to rotate the cell groups regularly to retain balance in the (very expensive) NiMH traction pack.

I don't know if that's the case with Lithiums (and their liquid cooling) on the Bolt, but don't be surprised with what you find.
 

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cell groups 65 to 72 are in the 3rd row back (section8) located on the drivers side, comprising half of the row

Does anyone have a Bolt EV battery diagram that corresponds to the TorquePro PIDs?

Basically, I want to know where certain cell groups physically reside in the battery, and in particular, whether they are in the same module. Specifically, my cell groups 65 to 72 are all reading one one-hundredth of a V lower than the rest of the cell groups.
 

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Discussion Starter #4
cell groups 65 to 72 are in the 3rd row back (section8) located on the drivers side, comprising half of the row
Thanks!

Just so I'm clear... The cell group tags do correspond to the actual layout of the battery? For example, Cell Group 1 is in Section 1.
 

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Yes the identify exactly where in the battery electrically they are located.
Your example:
Section 1 has 10 cell groups (as does section 8), each group has 3 cells in parallel.
Each section starting at section one, contains a group of either 10 or 8 cell groups, is numbered going clockwise starting at 1 on the front passenger side, ending at 10 at the front drivers side.


Thanks!

Just so I'm clear... The cell group tags do correspond to the actual layout of the battery? For example, Cell Group 1 is in Section 1.
 

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Each section starting at section one, contains a group of either 10 or 8 cell groups, is numbered going clockwise starting at 1 on the front passenger side, ending at 10 at the front drivers side.
Do you know this as a fact or are you just guessing? Are the two smaller modules 5 and 6?
 

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Do you know this as a fact or are you just guessing? Are the two smaller modules 5 and 6?
This is a fact. If you sit and watch the Weber Auto video, backing up, over and over, with a piece of paper and pencil, as I did, you will learn that Section 1 extends across under the front seats. It contains Module 1 on the passenger side, and Module 10 on the driver side. Module 1 contains cell groups 1-10. Module 10 contains cell groups 87-96. Module 1 has Thermistor 1 on its outer end. Module 10 has Thermistor 6 on its outer end. This is why thermistor 1, and Thermistor 6 often sit at exactly the same temperature, even though T1 is at the inlet of the coolant plate, and T6 is on the outlet. The two modules are attached permanently end-to-end.

[correction] Went back and re-watched the videos. The coolant plates; both the big bottom one, and the small upper one, have two inlets at the outer edges, and a single outlet at the center. So coolant flows in from the outsides, and back through the center of the pack. The passages actually alternate from narrow to wide as they go, and the incoming passages and outgoing passages intertwine.

https://youtu.be/ssU2mjiNi_Q?t=5428

S1=M1(1-10, T1)+M10(87-96,T6) Under front seats
S2=M2(11-20,T2)+M9(77-86)
S3=M3(21-30)+M8(67-76,T5)
S4=M4(31-40)+M7(59-66) Under rear seat
S5=M5(41-48,T3)+M6(49-58,T4) On top of Section 4, under rear seat. Module 5 and Module 6 are often warmest, because heat rises. Module 6 is always the warmest because the BMS sits on top of it.
 

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Just to clarify, DrZip is wrong on the cells in Module 8. It is NOT 65-72. It is 67-76. It is easy to mess up because of the two 8 cell modules. If you get their locations wrong, your sequence will be thrown off.

The rear two stacked Sections, 4 and 5, are the ones containing one 8 cell, and one 10 cell module each. I confirmed this from GM drawings, and from the Weber video.

https://insideevs.com/wp-content/uploads/2016/12/chevrolet-bolt-powertrain-17_003-750x355.jpg
 

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Does anyone have a Bolt EV battery diagram that corresponds to the TorquePro PIDs?

Basically, I want to know where certain cell groups physically reside in the battery, and in particular, whether they are in the same module. Specifically, my cell groups 65 to 72 are all reading one one-hundredth of a V lower than the rest of the cell groups.
I notice that the voltages are around 3.89, that means that this is after driving for a while, rather than after completing a charge. I'll claim that it is slightly more meaningful (or at least different!) to look at the voltages after a charge is complete because that is when the BMS will do battery balancing to get all the batteries up to the same point.

The fact that battery balancing is required shows that some variation is normal and expected.

There is some individual variation between batteries, and it is not unreasonable that a given module would have batteries that came out of the same “performance bin” after testing. I'm not an expert, but I don't think a 1% difference is much to worry about.
 

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Does anyone have a Bolt EV battery diagram that corresponds to the TorquePro PIDs?
Please see my posts from today. The cells you mention are wired sequentially in series, but as it happens, they are in different modules, in different sections. I have my cell gages set to three decimal places, and arranged in module groups, along with their thermistor. I see some grouping of like voltage, but I also see some random ones. And after much staring at them, I determined that my cell 16 is always the highest reading, and cell 70 is always the lowest. I made duplicate gages for these two, placed on either side of the average voltage gage. Cell 16 is always one hundredth of a volt above the average, and cell 70 is always one hundredth of a volt below the average. This is not literally true, as they will be off for an instant when the third decimal place is about to flip.

I have seen readouts from Teslas, on YouTube, and they had a spread of two hundredths of a volt across their 96 "cells" as well. So I don't think your Bolt is unusual in that regard.
 

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Please see my posts from today. The cells you mention are wired sequentially in series, but as it happens, they are in different modules, in different sections. I have my cell gages set to three decimal places, and arranged in module groups, along with their thermistor. I see some grouping of like voltage, but I also see some random ones. And after much staring at them, I determined that my cell 16 is always the highest reading, and cell 70 is always the lowest. I made duplicate gages for these two, placed on either side of the average voltage gage. Cell 16 is always one hundredth of a volt above the average, and cell 70 is always one hundredth of a volt below the average. This is not literally true, as they will be off for an instant when the third decimal place is about to flip.

I have seen readouts from Teslas, on YouTube, and they had a spread of two hundredths of a volt across their 96 "cells" as well. So I don't think your Bolt is unusual in that regard.
I read your posts on this thread with awe. My reaction was "wow - a person who is even more ... ummm ... (lets call it) 'precision oriented" on things that matter and might make a difference".

Bravo! (and very useful info). Thanks!!
 

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A hundredth of a volt difference is less than 1% and too negligible to be of concern. The drop in the wiring can add that amount due to the high currents and wiring resistance (V = I x R) causing the difference.
 
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