# 1st gen Chevy Volt battery dimensions



## hotspoons (Dec 31, 2020)

Good evening,

I am in the process of determining feasibility for an EV conversion project, and I am having trouble finding authorative information regarding dimensions for the various "modules" in a 1st gen Chevy Volt battery pack.

I am trying to find the overall lengths, not including the cooling bungs, for the various modules in this pack. These are the best dimensions I have on these various components after scouring the internet and trying to scale drawings I found, but I don't think they are correct:

Cell frame bottom width: 11" (not including steel mounting plate)
Cell frame top width: 9.8"
Cell frame height: 9.8" (not including cover or BMS)
4 + 3 KWh module (with center cooling frame) length: ?? "
5 KWh module length: 29"
4 KWh module length: 22.6"
3 KWh (sub) module length: 17.2"
And I am also looking for these figures, which I haven't been able to find:

Total height from cell bottom to BMS slave module top: ?? "
Total width between the outside of the mounting pocket and the outside of the retainer plate: ?? "
Any help you can give with correcting my figures above would be much appreciated! And if you have any cad drawings or diagrams to share, that would be great as well! Thank you,

Rich


----------



## hotspoons (Dec 31, 2020)

Here's the best I can do annotating an image on my phone, but maybe this helps clearing up what I'm after.


----------



## hotspoons (Dec 31, 2020)

I normally don't bump threads, but my account was in purgatory for over 2 weeks so my post remained invisible until yesterday, so _bump_


----------



## 4G63T (Jan 9, 2019)

Here is a nice video about the Volt battery pack (mainly the Gen 2) . He does compare the cells between gen 1 and 2 . They seem to look identical . He doesn’t mention the exact dimensions of the modules but does show number of cells and voltages etc.. it’s an overall good video to watch .


----------



## 4G63T (Jan 9, 2019)

Also sharing this I found for some technical data from GM comparing the Gen 1 to Gen 2 .


https://media.gm.com/content/dam/Media/microsites/product/Volt_2016/doc/VOLT_BATTERY.pdf


----------



## hotspoons (Dec 31, 2020)

4G63T said:


> Here is a nice video about the Volt battery pack (mainly the Gen 2) . He does compare the cells between gen 1 and 2 . They seem to look identical . He doesn’t mention the exact dimensions of the modules but does show number of cells and voltages etc.. it’s an overall good video to watch .





4G63T said:


> Also sharing this I found for some technical data from GM comparing the Gen 1 to Gen 2 .
> 
> 
> https://media.gm.com/content/dam/Media/microsites/product/Volt_2016/doc/VOLT_BATTERY.pdf


Thank you 4G63T! I came across that video before but wasn't able to devote the time to watch it, maybe I'll try tonight. I was able to find a little more info here and here, but neither was really specific enough. The 1st and 2nd gen batteries look very similar, but they are different chemistries and configurations. 

Basically, I am trying to make a crude but accurate model of these battery modules in CAD to test fitment for a few ideas I have for a project, but I am not confident that the couple of anecdotes I have come across for measurements are accurate, and I know that a lot of folks here have dealt with these batteries before, so I was hoping someone had something more accurate (or drafted in CAD)! 

Thanks!


----------



## brian_ (Feb 7, 2017)

hotspoons said:


> The 1st and 2nd gen batteries look very similar, but they are different chemistries and configurations.


The second generation has only two-thirds as many cells so the cells are obviously thicker, and they are grouped in different combinations, but otherwise the dimensions are likely identical.

Most DIY builders seem to use the first generation modules, so you're more likely to find those dimensions.

The chemistry according to GM (see the document linked by 4G63T) is NMC-LMO for both generations.


----------



## swoozle (Nov 13, 2011)

Missed this when you first posted. I have a full set of Gen 1 modules loose (no mounting plate). Let me know what specific dimensions you want beyond the couple I include below. 

The 7kwh subassembly length is 33 1/4". That's the longest dimension, which is the ends of the compression bolts. The heads and tails stick out a little from the endplate surfaces.

The dimension from bottom of the module to top of the slave case is 10 15/16" as near as I can tell (photo is not at exactly the right angle to see that).


----------



## hotspoons (Dec 31, 2020)

swoozle said:


> Missed this when you first posted. I have a full set of Gen 1 modules loose (no mounting plate). Let me know what specific dimensions you want beyond the couple I include below.
> 
> The 7kwh subassembly length is 33 1/4". That's the longest dimension, which is the ends of the compression bolts. The heads and tails stick out a little from the endplate surfaces.
> 
> ...


Thank you so much!! Would you mind getting or verifying for me:

The width of at the bottom of one of the sub-assemblies (where the battery is the widest - best guess is 9 3/8")
The width at the top of the battery, where the compression band would go (best guess is 7")
The length of the 4 and 5 KWh sub-assemblies at the compression bolts (e.g. not including cooling bungs)
The length of the 3 KWh sub-module that is part of the 7KWh sub-assemblies, between the compression bolt and the coolant bung frame?
Thanks again!


----------



## swoozle (Nov 13, 2011)

hotspoons said:


> Thank you so much!! Would you mind getting or verifying for me:
> 
> The width of at the bottom of one of the sub-assemblies (where the battery is the widest - best guess is 9 3/8")
> The width at the top of the battery, where the compression band would go (best guess is 7")
> ...


Bottom width at the mounting flanges is 9 1/4. The cooling channel sticks out a little further on one side so the overall width is 9 7/16.
Width at the compression band (without the band) is 6 3/4. With the band 6 13/16.
4 kwh module length (to ends of bolt) 18 13/16
5 kwh module length (to ends of bolt) 23 1/2
3 kwh section of large module (from end of bolt to face of last cell) 13 7/8

Happy to do it. Let me know if you need anything else.


----------



## hotspoons (Dec 31, 2020)

swoozle said:


> Bottom width at the mounting flanges is 9 1/4. The cooling channel sticks out a little further on one side so the overall width is 9 7/16.
> Width at the compression band (without the band) is 6 3/4. With the band 6 13/16.
> 4 kwh module length (to ends of bolt) 18 13/16
> 5 kwh module length (to ends of bolt) 23 1/2
> ...


Thank you swoozle!! This is a great help. I have everything I need for right now, but I'll want to model the coolant bungs eventually to check clearances for an application I'm modelling up, so I may bug you again later. Once I redraft the frames more realistically and have something that looks more realistic, I'll share what I mocked up to hopefully help someone else. 

Thanks again!!


----------



## MarkMark1 (May 11, 2021)

How did you go with the mock-up?


----------

