Volt gen2 BMS

Topics concerning OEM and open source BMSes
Post Reply
arber333
Posts: 2000
Joined: Mon Dec 24, 2018 1:37 pm
Location: Slovenia
Contact:

Volt gen2 BMS

Post by arber333 »

I have one 18kWh Volt gen2 2018 battery at home. Also i will get complete BMS with harness. Right now i am missing front face with current sensor and contactors. Also i have invested whole 15€ into accessing the Chevrolet workshop documentation here: https://www.repairprocedures.com/
Now i have pics of relavant connectors and schematics.
My intention is to fuse them together into original configuration and use the Fault output of BMS to signal the edges of cell envelope.

From schematic i see system uses 12V to power BMS and ignition signal +12V from key. Output is CAN signal and one 5V Fault signal line.

is anyone interested to develop CAN communication for Gen2 Volt BMS? The way i see BMS is very similar to Bolt BMS. What would be the odds? 8-)
Attachments
BECM.jpg
Battery.jpg
User avatar
Bratitude
Posts: 380
Joined: Thu Jan 02, 2020 7:35 pm
Location: Canada
Contact:

Re: Volt gen2 BMS

Post by Bratitude »

Found this post on the PIDs for the bolt https://www.chevybolt.org/threads/chevr ... 666/page-2

I have a original bms harness coming in, I’ll see what I can read with what we have so far.
https://bratindustries.net/ leaf couplers + adapter plates
arber333
Posts: 2000
Joined: Mon Dec 24, 2018 1:37 pm
Location: Slovenia
Contact:

Re: Volt gen2 BMS

Post by arber333 »

Bratitude wrote: Sat Oct 17, 2020 11:47 am Found this post on the PIDs for the bolt https://www.chevybolt.org/threads/chevr ... 666/page-2

I have a original bms harness coming in, I’ll see what I can read with what we have so far.
Really good, thanks.
I found out this BMS is stand alone and it only needs 12V enable signal to turn it on. However i found out that the person who sold me the battery and BMS forgot to send me the front plate. In that front plate is a current sensor which is a mandatory part for the BMS to work. I am now waiting for the front plate to arrive so that i can start my experiments.
User avatar
Bratitude
Posts: 380
Joined: Thu Jan 02, 2020 7:35 pm
Location: Canada
Contact:

Re: Volt gen2 BMS

Post by Bratitude »

arber333 wrote: Sat Oct 17, 2020 5:04 pm
Bratitude wrote: Sat Oct 17, 2020 11:47 am Found this post on the PIDs for the bolt https://www.chevybolt.org/threads/chevr ... 666/page-2

I have a original bms harness coming in, I’ll see what I can read with what we have so far.
Really good, thanks.
I found out this BMS is stand alone and it only needs 12V enable signal to turn it on. However i found out that the person who sold me the battery and BMS forgot to send me the front plate. In that front plate is a current sensor which is a mandatory part for the BMS to work. I am now waiting for the front plate to arrive so that i can start my experiments.

looks like we should be able to get soc, volt/amp draw and temp with out any fuss.

the front plate has the battery heater and control hardware as well. from what it looks like it will automatically do some temperature regulation.

this appears to be dependent on a few outside factors. Such as is the car is plugged in or the engine is running? I’m going to take a guess this is a CAN Id we need to find. I guess we’ll find out soon enough 😄
https://bratindustries.net/ leaf couplers + adapter plates
arber333
Posts: 2000
Joined: Mon Dec 24, 2018 1:37 pm
Location: Slovenia
Contact:

Re: Volt gen2 BMS

Post by arber333 »

Bratitude wrote: Sat Oct 17, 2020 5:56 pm looks like we should be able to get soc, volt/amp draw and temp with out any fuss.

the front plate has the battery heater and control hardware as well. from what it looks like it will automatically do some temperature regulation.

this appears to be dependent on a few outside factors. Such as is the car is plugged in or the engine is running? I’m going to take a guess this is a CAN Id we need to find. I guess we’ll find out soon enough 😄
The way wiring schematic looks it still depends on HPCM2 which is located under the passanger seat.
But charger and DCDC this time are not run by CAN bus but rather by PWM signal which is more characteristical for coolant pumps and fans...
User avatar
Bratitude
Posts: 380
Joined: Thu Jan 02, 2020 7:35 pm
Location: Canada
Contact:

Re: Volt gen2 BMS

Post by Bratitude »

new bms harness is in. it seems there might be some year variation between the gen2 battery. the connector interface to the face box (contactors/heater/current sensor) are different.

connections to the battery and bms are the same.
https://bratindustries.net/ leaf couplers + adapter plates
User avatar
Bratitude
Posts: 380
Joined: Thu Jan 02, 2020 7:35 pm
Location: Canada
Contact:

Re: Volt gen2 BMS

Post by Bratitude »

mid year change in bms harness. Must be connector cost reduction.
my new harness won’t interface to the old relay box harness. see connector difference:
F26900E7-5AB4-490E-8163-4E509129DB1B.jpeg
Separated the harness, and split out the stuff for everything other than cell voltage and cell temp monitoring. Taped it all back up. Then swapped over what was left of the older harness with the new.
710D021A-2910-4558-BCDE-A08124756192.jpeg
Half of the green connector takes in some cell and temp signals, where the other half takes in the water temp and current sensor, which are part of the relay harness.
These 6pins where the only pins I needed to swap on the connector. Everything else stays.
4A1C68A3-6F1A-4C38-94D4-B4550D26307F.jpeg
On the other side of the bms box the black connector directly across from the green one handles all 3 can lines, power, ignition. This is easily separated from the loom.
85379C46-8325-4FF9-AF0F-733A97A4188F.jpeg
Once separated, there will be 2 lines for heater temp that rout to the green connector, and 2 lines that rout to the service disconnect. Service disconnect lines you can ignore as these do not interface to the bms.

now with that all swapped over, the relay box/heater/current sensor loom plugs in with the old connector and I have the lines needed to start testing.
297AA80B-6650-4A6F-BBDE-C8E9F9763A9C.jpeg
relays and water heater are not controlled via the bms, like arber stated earlier.

The faceplate connector ends where cut off as I’m not using the face plate. so that leaves just 3 Canbus’s, 12v power, ignition signal, 5v fault?

@arber333 do you have anymore photos of pin out from the manual?
https://bratindustries.net/ leaf couplers + adapter plates
arber333
Posts: 2000
Joined: Mon Dec 24, 2018 1:37 pm
Location: Slovenia
Contact:

Re: Volt gen2 BMS

Post by arber333 »

Bratitude wrote: Fri Oct 30, 2020 6:02 pm The faceplate ends where cut off as I’m not using the face plate. so that leaves just 3 Canbus’s, power, ignition and a few others wires.
@arber333 do you have a photo of the pin out diagram from the manual?
Yeah i have them and i will upload them to my github. I am working on Outlander charger interface right now so please bear with me.

Also you do need to connect Current sensor into the BMS master unit. It is located on the front panel behind contactors and it seems to be DHAB S/51.
https://github.com/arber333/Volt-2-BMS
User avatar
Bratitude
Posts: 380
Joined: Thu Jan 02, 2020 7:35 pm
Location: Canada
Contact:

Re: Volt gen2 BMS

Post by Bratitude »

arber333 wrote: Fri Oct 30, 2020 7:07 pm
Bratitude wrote: Fri Oct 30, 2020 6:02 pm The faceplate ends where cut off as I’m not using the face plate. so that leaves just 3 Canbus’s, power, ignition and a few others wires.
@arber333 do you have a photo of the pin out diagram from the manual?
Yeah i have them and i will upload them to my github. I am working on Outlander charger interface right now so please bear with me.

Also you do need to connect Current sensor into the BMS master unit. It is located on the front panel behind contactors and it seems to be DHAB S/51.
https://github.com/arber333/Volt-2-BMS
Awesome thanks!
BECM Konektor8.jpg
And yup! the current sensor from the face plate and the water temp sensor are connected.
https://bratindustries.net/ leaf couplers + adapter plates
User avatar
Bratitude
Posts: 380
Joined: Thu Jan 02, 2020 7:35 pm
Location: Canada
Contact:

Re: Volt gen2 BMS

Post by Bratitude »

started doing some logging.
first log is- no battery module connected. second - module connected, third -module connected, and applying heat and then cooling and heating the water temp senor.
volt_gen2_bms.csv
(100.72 KiB) Downloaded 37 times
volt_gen2_bms_batterymoduleone.csv
(1.52 MiB) Downloaded 31 times
volt_gen2_bms_batterymoduleone_watertemp.csv
(1.52 MiB) Downloaded 28 times

im new to this, but im taking guess that 0x216 is water temp?
and 0x270, 0x272 are possibly cell voltages?
https://bratindustries.net/ leaf couplers + adapter plates
User avatar
Bratitude
Posts: 380
Joined: Thu Jan 02, 2020 7:35 pm
Location: Canada
Contact:

Re: Volt gen2 BMS

Post by Bratitude »

Sparke ev uses the same cell modules, and looks like the same becm too.

so after some more digging:

http://www.mychevysparkev.com/forum/vie ... 6&start=20

https://gist.github.com/anonymous/b6d68 ... rk-ev-becm

and the work DrJeff / teslorean has done to get his spark pack working for him.

https://github.com/DrJeffCooke/TesLorea ... Controller
https://bratindustries.net/ leaf couplers + adapter plates
TonyV
Posts: 66
Joined: Sat Nov 14, 2020 9:00 pm
Location: Toronto
Contact:

Re: Volt gen2 BMS

Post by TonyV »

What program are you using to read all the statues of all the cells?
I'll figure this out sooner or later
User avatar
Bratitude
Posts: 380
Joined: Thu Jan 02, 2020 7:35 pm
Location: Canada
Contact:

Re: Volt gen2 BMS

Post by Bratitude »

TonyV wrote: Sat Nov 28, 2020 4:30 am What program are you using to read all the statues of all the cells?
Currently have not deciphered the can ids to tell use the statues of the cells.

have a read threw the thread please
https://bratindustries.net/ leaf couplers + adapter plates
User avatar
mayes8229
Posts: 17
Joined: Mon Jan 25, 2021 7:18 am
Location: Durham, NC USA

Re: Volt gen2 BMS

Post by mayes8229 »

I'm going to start working on getting the Gen2 BMS working for me soon, but I was curious about one thing: Does the BMS care about the pack configuration? In other words, does the BMS monitor the expected voltage as cells/modules add up, or does it only look at the individual cell voltages? Wondering if I'll run into problems because I have the modules connected in a different order from stock.
arber333
Posts: 2000
Joined: Mon Dec 24, 2018 1:37 pm
Location: Slovenia
Contact:

Re: Volt gen2 BMS

Post by arber333 »

mayes8229 wrote: Mon Feb 01, 2021 11:08 pm I'm going to start working on getting the Gen2 BMS working for me soon, but I was curious about one thing: Does the BMS care about the pack configuration? In other words, does the BMS monitor the expected voltage as cells/modules add up, or does it only look at the individual cell voltages? Wondering if I'll run into problems because I have the modules connected in a different order from stock.
It is essential you have all the cells connected in correct order with modules interconnected and then connect BMS per manual. The gen2 BMS is a single board unit which monitors voltages and needs to compare readings from successive cell locations. If you would take cells apart and have BMS still connected i could harm the electronics inside. See WeberAuto Volt battery disassembly video at 1:17:00.
User avatar
mayes8229
Posts: 17
Joined: Mon Jan 25, 2021 7:18 am
Location: Durham, NC USA

Re: Volt gen2 BMS

Post by mayes8229 »

arber333 wrote: Tue Feb 02, 2021 12:01 pm
mayes8229 wrote: Mon Feb 01, 2021 11:08 pm I'm going to start working on getting the Gen2 BMS working for me soon, but I was curious about one thing: Does the BMS care about the pack configuration? In other words, does the BMS monitor the expected voltage as cells/modules add up, or does it only look at the individual cell voltages? Wondering if I'll run into problems because I have the modules connected in a different order from stock.
It is essential you have all the cells connected in correct order with modules interconnected and then connect BMS per manual. The gen2 BMS is a single board unit which monitors voltages and needs to compare readings from successive cell locations. If you would take cells apart and have BMS still connected i could harm the electronics inside. See WeberAuto Volt battery disassembly video at 1:17:00.
Thanks! Looks like my configuration will still work because I can connect the module banks I have in the same cell order as the original layout.
User avatar
Bratitude
Posts: 380
Joined: Thu Jan 02, 2020 7:35 pm
Location: Canada
Contact:

Re: Volt gen2 BMS

Post by Bratitude »

mayes8229 wrote: Tue Feb 02, 2021 8:27 pm
arber333 wrote: Tue Feb 02, 2021 12:01 pm
mayes8229 wrote: Mon Feb 01, 2021 11:08 pm I'm going to start working on getting the Gen2 BMS working for me soon, but I was curious about one thing: Does the BMS care about the pack configuration? In other words, does the BMS monitor the expected voltage as cells/modules add up, or does it only look at the individual cell voltages? Wondering if I'll run into problems because I have the modules connected in a different order from stock.
It is essential you have all the cells connected in correct order with modules interconnected and then connect BMS per manual. The gen2 BMS is a single board unit which monitors voltages and needs to compare readings from successive cell locations. If you would take cells apart and have BMS still connected i could harm the electronics inside. See WeberAuto Volt battery disassembly video at 1:17:00.
Thanks! Looks like my configuration will still work because I can connect the module banks I have in the same cell order as the original layout.

Yes, if the sub modules make the same Sequence as stock you are okay. being there are 2 different sub modules
https://bratindustries.net/ leaf couplers + adapter plates
86elcamino
Posts: 20
Joined: Thu Apr 15, 2021 12:06 am
Location: Lake Jackson, Tx

Re: Volt gen2 BMS

Post by 86elcamino »

Does anyone have this BMS running on a vehicle? I'm going to use a Gen 2 Volt battery pack, (possibly 2 or 3 packs if all goes well) with the Zombieverter and GS450H transmission.
User avatar
Bratitude
Posts: 380
Joined: Thu Jan 02, 2020 7:35 pm
Location: Canada
Contact:

Re: Volt gen2 BMS

Post by Bratitude »

decided to do some digging again, and looks like the bolt, spark, taho hybrid and gen2 volt use the same BECM module.

found this CVS file of the PIDs for the bolt, hopefully this is every needed to at least measure soc, soh, and cell voltages

https://docs.google.com/spreadsheets/d/ ... =946940079
https://bratindustries.net/ leaf couplers + adapter plates
geduxaz
Posts: 31
Joined: Wed Jun 23, 2021 7:00 am

Re: Volt gen2 BMS

Post by geduxaz »

Hi Guru!
Can Volt Gen2 BMS be started to balance battery of like 80 or less cells? Or it must have all 96? I am working with smaller Volt battery (damaged cells were removed) and have 80cells and BMS with wirring.
In general now i need only balancing/monitoring to safely charge/discharge the battery.
Is current sensor mandatory to start BMS? I didnt get it in the kit :(
KimchiKimKim
Posts: 36
Joined: Wed Mar 03, 2021 1:36 am
Location: California
Contact:

Re: Volt gen2 BMS

Post by KimchiKimKim »

Bratitude wrote: Mon Jan 10, 2022 8:25 pm decided to do some digging again, and looks like the bolt, spark, taho hybrid and gen2 volt use the same BECM module.

found this CVS file of the PIDs for the bolt, hopefully this is every needed to at least measure soc, soh, and cell voltages

https://docs.google.com/spreadsheets/d/ ... =946940079
Thank you so much for linking this.
User avatar
Bratitude
Posts: 380
Joined: Thu Jan 02, 2020 7:35 pm
Location: Canada
Contact:

Re: Volt gen2 BMS

Post by Bratitude »

okay so some success! did some more digging, loaded up "gm_global_a_high_voltage_management.dbc" i stole from opendbc https://github.com/commaai/opendbc into savy can and boom! i got cell voltages and temps



0x302
cell temps
0x460
coolent temps
https://bratindustries.net/ leaf couplers + adapter plates
arber333
Posts: 2000
Joined: Mon Dec 24, 2018 1:37 pm
Location: Slovenia
Contact:

Re: Volt gen2 BMS

Post by arber333 »

Bratitude wrote: Fri Jan 21, 2022 6:28 pm okay so some success! did some more digging, loaded up "gm_global_a_high_voltage_management.dbc" i stole from opendbc https://github.com/commaai/opendbc into savy can and boom! i got cell voltages and temps
Good find!
But isnt that file for Volt gen1 and Ampera BMS? Or do they both share the same CAN IDs?
You know actually that would make sense since HPCM2 module which is a battery/charging master seems the same from gen1 to gen2.

So cell voltages are in ID 0x512, 0x514, 0x516 and 0x518
Pack current and voltages are 0x528 then
User avatar
Bratitude
Posts: 380
Joined: Thu Jan 02, 2020 7:35 pm
Location: Canada
Contact:

Re: Volt gen2 BMS

Post by Bratitude »

arber333 wrote: Fri Jan 21, 2022 9:30 pm good find!

...

So cell voltages are in ID 0x512, 0x514, 0x516 and 0x518
Pack current and voltages are 0x528 then
cheers, okay so far all im seeing from providing +12v is:
0x200
0x202
0x204
0x206
0x208
0x20C
0x216
0x260
0x262
0x270
0x272
0x274
0x304
0x460

i pluged in a few of the cell taps and now 0x302 and 0x460 are now reading out cell voltages, no longer displaying the coolent temps or cell temps.
https://bratindustries.net/ leaf couplers + adapter plates
Post Reply