# Using stock Chevy Volt BMS



## rx7r3ev (Dec 11, 2018)

Has anybody tried and use the stock Chevy Volt BMS for their conversion?

Looking around the net (and in here), I come across two interesting information:

First:
Keep the original BMS and just power up the Battery Energy Control Module (BECM). I guess the idea in here is just to let the BECM does its thing to balance the pack. Here's the reference I've come across -

http://electricgokart36v.blogspot.com/2017/06/re-using-chevy-volt-oem-bms-for-ev.html

Has anybody attempted this and has it worked for you? 

Second:
This approach is a bit involved and requires programming to send CAN messages to the Battery Interface Module (the slave to the BECM). If the first approach does not work this is probably the next option to manually do your own custom cell management. Here's the reference form this forum and the thread originator did a really good job on this one -

https://www.diyelectriccar.com/forums/showthread.php/1st-gen-chevy-volt-bms-balance-200023.html

Thanks!


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## mpobor (Jul 9, 2018)

rx7r3ev said:


> Has anybody tried and use the stock Chevy Volt BMS for their conversion?
> 
> Looking around the net (and in here), I come across two interesting information:
> 
> ...



Im on the same route here... I can see both Damien Mcguire with his panzer and the Tesla bimmer using OEM bms... I'm sanding email to Damien because looks like he can chademo charge its volt pack and I think it's using OEM BMs... So Im asking him how he did that.. But no reply yet its busy with fully charge channel


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## CanadaLT28 (Oct 15, 2011)

mpobor said:


> Im on the same route here... I can see both Damien Mcguire with his panzer and the Tesla bimmer using OEM bms... I'm sanding email to Damien because looks like he can chademo charge its volt pack and I think it's using OEM BMs... So Im asking him how he did that.. But no reply yet its busy with fully charge channel



Did you donate to his Patreon channel. He may not answer without it.


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## swoozle (Nov 13, 2011)

rx7r3ev said:


> Has anybody tried and use the stock Chevy Volt BMS for their conversion?
> 
> Looking around the net (and in here), I come across two interesting information:
> 
> ...


From what I've seen of the BECM-BICM traffic, and has been confirmed by others looking into it, the balancing commands do not come from the BECM. If you want to do balancing pretty much your only choices are to talk to the BICMs yourself (which I'm doing) or use Tomdb's SimpBMS to run the BICMs.


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## swoozle (Nov 13, 2011)

mpobor said:


> Im on the same route here... I can see both Damien Mcguire with his panzer and the Tesla bimmer using OEM bms... I'm sanding email to Damien because looks like he can chademo charge its volt pack and I think it's using OEM BMs... So Im asking him how he did that.. But no reply yet its busy with fully charge channel


Damien uses SimpBMS.


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## CanadaLT28 (Oct 15, 2011)

swoozle said:


> Damien uses SimpBMS.



From what I have seen of Damien, he is not trying to combine packs or chargers in one car like I am. Having 4 packs in a truck and using one Lear charger just doesn't cut it, nor does the expense of having 4 chargers, 4 SimBMS (for example).



I think some of these questions come about because there is no single space with facts about what works and what doesn't. It's pretty hard at times, to keep up with the multiple threads of info and not miss stuff.


I'm DIY in almost everything but circuits and programming make me hit a brick wall.


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## MattsAwesomeStuff (Aug 10, 2017)

CanadaLT28 said:


> I think some of these questions come about because there is no single space with facts about what works and what doesn't. It's pretty hard at times, to keep up with the multiple threads of info and not miss stuff.


The community does a pretty poor job of colimating that information. Partly I think because there'd no leadership group here like naturally occurs in most communities. And I think that's largely because the community has no sense of ownership over their own community, (because they don't, and because our hosts are awful).


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## wigman (Oct 16, 2019)

I'm attempting to do something similar and would like to buy a CAN reader that would utilize the stock Volt BMS system. 

I emailed slevb about the simp BMS but they said it does not support the Volt BMS.

I also saw tesla bimmer using the stock BMS but cannot find in his build history an explanation of how he did it. He uses thunderstuck CAN for the charger and dcdc converter. I talked to Thunderstruck and they said they don't have a way to talk to the Volt BMS through that system either.


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## Tomdb (Jan 28, 2013)

It is the SimpBMS, yes it does work. Slevb are a reseller of mine.

information: https://github.com/tomdebree/SimpBMS

If you are interested shoot me a private message


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## CanadaLT28 (Oct 15, 2011)

Tomdb said:


> It is the SimpBMS, yes it does work. Slevb are a reseller of mine.
> 
> information: https://github.com/tomdebree/SimpBMS
> 
> If you are interested shoot me a private message



Any news on the SimpBMS for 2 packs yet?


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## Tomdb (Jan 28, 2013)

CanadaLT28 said:


> Any news on the SimpBMS for 2 packs yet?


Unfortunately, this is a side job for me. 

I have now worked out a way to get a second canbus to control things like the DCDC and Charger. However this bus is too slow, as in software overhead, to do an additional pack with slaves.

The multipack system will be looked at, but its down the list of jobs to be completed currently. I hope at some point to find time to work on it in the coming months.


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## CanadaLT28 (Oct 15, 2011)

Tomdb said:


> Unfortunately, this is a side job for me.
> 
> I have now worked out a way to get a second canbus to control things like the DCDC and Charger. However this bus is too slow, as in software overhead, to do an additional pack with slaves.
> 
> The multipack system will be looked at, but its down the list of jobs to be completed currently. I hope at some point to find time to work on it in the coming months.



That's OK. I have soo much to do as it is. Good thing about the DCDC and Charger. Will I be able to use it with the Tesla charger on the volt pack(s) or will there be no compatibility at all?


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## Tomdb (Jan 28, 2013)

CanadaLT28 said:


> That's OK. I have soo much to do as it is. Good thing about the DCDC and Charger. Will I be able to use it with the Tesla charger on the volt pack(s) or will there be no compatibility at all?


Tesla Charger is just enable with 12V signal for now using the opensource board. 

The newer versions of opensource boards do not even support external Can Bus.


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## BogdanT (Sep 15, 2018)

CanadaLT28 said:


> Any news on the SimpBMS for 2 packs yet?


Have you considered paralleling them at the cell level like Yabert did?
https://www.diyelectriccar.com/forums/showthread.php/showpost.php?p=688185

It will be a ton of work but that way you could have a single BMS working for all the cells.


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## CanadaLT28 (Oct 15, 2011)

BogdanT said:


> Have you considered paralleling them at the cell level like Yabert did?
> https://www.diyelectriccar.com/forums/showthread.php/showpost.php?p=688185
> 
> It will be a ton of work but that way you could have a single BMS working for all the cells.



I thought about that but you are right, when the current battery has all the right parts in all the right places and only needs to be plugged in, I'm reluctant to pull it apart.


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## arber333 (Dec 13, 2010)

Hi Swoozle

I have a question if i may. Two actually...
I would like to use complete Volt battery with complete Volt BMS up to BICM, BECM and current sensor, interlock etc... but without underseat control module. 
I actually have it, but i dont want to hassle with all the cabling. 
What i need is an option of over/under voltage trigger from BMS. 

1. Did you in your work find anything that could be used to shutoff charger or put a car in turtle mode if we overstep some boundry?

2. Did you find out what that boundry is? I.e.: overvoltage 4.2V / undervoltage 2.8V or other.... 

If we find out this i wont bother with balancing since i will only charge to 4V per cell.


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## swoozle (Nov 13, 2011)

arber333 said:


> Hi Swoozle
> 
> I have a question if i may. Two actually...
> I would like to use complete Volt battery with complete Volt BMS up to BICM, BECM and current sensor, interlock etc... but without underseat control module.
> ...



Woop, I just noticed you asked this on the forum in addition to PM. So here's my response for other folks, too:

No, I didn't get into that kind of investigation. I only pull the cell voltage and temp readings out of the BICMs over CAN and work with them using a Raspberry Pi.

I'm sure you've seen the "high-voltage fault" line that runs from the BICMs to the BECM. I have not looked into what triggers it, but I assume it is something major like a ground fault. I always assumed that the BECM performs the functions you are looking for.

That sounds like quite a challenge. Good luck!


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## arber333 (Dec 13, 2010)

Yes, yesterday i was working with full Ampera BMS setup. BECM and slaves connected with current and temp sensors. 
I dont have contactor and charging relay assembly connected though. 

1. I inspected X1 connector for any digital signals that may be flying around. There is none. I noticed pin 13 is 2.5V in every case and pin 14 is at GND level.

2. I tried to provoke reaction from any of the pins when i disconnect a BMS slave. reaction is evident from appropriate CAN ID, but as far as i know there is no digital pin on X1 that sends a "fault" signal if something happens, besides comms traffic on CAN that is...

3. Now I need to test the side outputs that go to relay assembly. I am sure they drive charge/discharge contactors. I need to see:
- they react to fault provocation
- translate what kind of events trigger that reaction
- find LVC and HVC levels 

4. Use original BECM with that info inside my car .


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## ConversionVirgin (Dec 16, 2019)

Did anyone get anywhere on this? I want to do The same with chevy spark. Pretty much use everything from the spark but the motor and keep the DC fast charging etc. I'm guessing some of it is similar to the chevy volt


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