# Attempting to hack a Chevy Volt Drivetrain



## kerrymann (Feb 17, 2011)

*Chevy Volt drivetrain *

I actually bought the entire EV drivetrain from a 2013 Chevy volt with 7k miles. After 3 attempts of buying a new volt battery (paying for, waiting months, and then getting a refund from the dealer) I just went with a scrapyard unit. A few weeks ago I started tearing apart the Chevy volt pack and video taped the tear down and here are the links: 

https://www.youtube.com/watch?v=00tTckGUv7I&list=UU1haWsGv-HcI10lapf4MBgg
https://www.youtube.com/watch?v=00tTckGUv7I&list=UU1haWsGv-HcI10lapf4MBgg


It's my first time shooting and editing video so future videos should be better quality


Here is a picture of the drivetrain sitting next to our daily driver volt (30,000 EV miles and going strong):​ 

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When I bought all the parts I made sure to get all the important wiring bits.​ 


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For those that don't know, the motor and inverter are very interesting, the motor is actually 2 motors. One is nested inside the other in a coaxial configuration and the inverter is actually two in one as well. It will take quite a bit of work to figure out how to talk to the inverter and very likely outside my capabilities (I am a ME not a EE for a reason . But a 111kW AC drive system for well under $1000 is a big opportunity for the DIY community.​ 


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Here is the engine side of the gear box. And on the bottom you can also see where the passenger side axle shaft comes out:​ 


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The Volt pack has a disconnect mounted on top. It is not the easiest to pull but I am pretty sure it is fused.​


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The pack cover is easily removed and the the whole pack is easy and straight forward to work on.​



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The pack is configured in 3 modules that are made up of 48V and 24V modules. The pack measured 370VDC total and is likely near a "full" charge. Keep in mind that chevy's version of a full charge is actually 80% SOC.​ 

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I took video of the whole process and will post it up on youtube once I get it all edited. The modules are pretty easy to breakdown and I will upload the pics from that process next week.​


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## skooler (Mar 26, 2011)

Awesome! 

Keep us updated


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## piotrsko (Dec 9, 2007)

Yup it's fused, 350 amps. Mine will deliver that for at least 2 minutes so far. Full Charge is rumored to be 400 volts. Lower limit 240 volts

The big thing would be to hack the battery for bms and other controls.

Chevy seems paranoid, everything inerts the pack.

Where did you get yours?


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## samwichse (Jan 28, 2012)

Is the inverter water cooled?


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## kerrymann (Feb 17, 2011)

I got it from a junkyard. It took me a bit because I didn't find one locally and it took a few attempts to find a yard willing to ship everything. Once I got a deal worked out on the battery the other parts were cheap. Even if I just end up scrapping the motor I won't be out much money. Because right now there is 0 market for them. If you wreck a volt enough to damage these parts it is going to be scrapped and with 8 year and 100k mile warranty there is no real replacement market. 

As far as the BMS, I know there are some on the forum looking at making the OEM BMS work which would be very cool but in the mean time I want to wire it to my Orion. With the right harness it should be a simple plug and play from the Orion to the individual modules. I have been talking to a few people about buying a harness (including Andrew at Orion) but nobody makes this so I am designing up my own.


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## piotrsko (Dec 9, 2007)

I'm guessing you have yours apart so you've seen the Orange bms tie points. Just whack the control board side off and add your own connection scheme. Just unplug them from battery first as I believe they are live. Should even be a standard spec connector.


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## kerrymann (Feb 17, 2011)

piotrsko said:


> I'm guessing you have yours apart so you've seen the Orange bms tie points. Just whack the control board side off and add your own connection scheme. Just unplug them from battery first as I believe they are live. Should even be a standard spec connector.


Yep. That certainly is an option. Ideally a cable could be made available that would allow anyone to plug straight from the modules to the Orion without even picking up a wire crimper.

I have been searching for a connector but in the mean time I could just depin the original connector a repin it. 

Here are pictures of the 6 and 12 modules.

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​ 
Also I forgot to mention that there is a current sensor located in between the front and middle modules


​


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## piotrsko (Dec 9, 2007)

Sensor is lem product dhab s44 a 0 to 600 amp inductive coupled DC. Runs on 5 v ref. Darn kindle won't paste the pdf here.

I'm lusting after modifications to the mains relays after I figure out what they break. 350 amp one shot perhaps.

Also many assorted imbedded thermocouple, and looks like a 600 watt heater element


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## esoneson (Sep 1, 2008)

kerrymann,

I'd like to use the Volt pack, but I'd like to break it up so get 190V and twice the Ah.
Question: Do you think the inter-module cabling can handle more than 300 Amps?

Looks like inter-module connections include HV cabling, cooling fluid and BMS cabling. Am I right or is there more to it?

Thanks. You are doing an excellent job at documenting this effort. Can't wait to see the vid.

Eric


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## kerrymann (Feb 17, 2011)

You could actually do that pretty easily. There are 7 of the 48v modules and 2 24V modules. They can be reconfigured into 2 192V packs (or 4 packs depending how it will be cooled) in parallel. The design of the modules will not handle high currents but putting in parallel will double the current and get you the voltage you need.


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## kerrymann (Feb 17, 2011)

piotrsko said:


> Sensor is lem product dhab s44 a 0 to 600 amp inductive coupled DC. Runs on 5 v ref. Darn kindle won't paste the pdf here.
> 
> I'm lusting after modifications to the mains relays after I figure out what they break. 350 amp one shot perhaps.
> 
> Also many assorted imbedded thermocouple, and looks like a 600 watt heater element


Thanks. If you can upload the .pdf that would be great! I have not noticed the heater yet. Where is it located?

Each module has a TC. Not sure what type though? (maybe a thermistor for all I know yet)


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## piotrsko (Dec 9, 2007)

http://www.lem.com/docs/products/dhab%20s44.pdf

heater is in input coolant manifold, orange 2 wire plug about 1/8 dia pins

each module has temp sensor.

two in metal endplate coolant manifolds, one in fuse (at least there is an impedance) two in wire charge plugs, thought they were T/C might be thermistors.


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## jddcircuit (Mar 18, 2010)

Good luck kerrymann. 

I got outbid on a couple online auctions but not giving up. I need the battery for my conversion using a Prius motor and inverter but I plan to hack the Volt drive train as well if things go as planned.

Jeff


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## kerrymann (Feb 17, 2011)

I finally got the video's edited and posted to youtube. 

https://www.youtube.com/watch?v=00tTckGUv7I&list=UU1haWsGv-HcI10lapf4MBgg
https://www.youtube.com/watch?v=00tTckGUv7I&list=UU1haWsGv-HcI10lapf4MBgg

It's my first time shooting and editing video so future videos should be better quality but I hope you guys find these informative.


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## kerrymann (Feb 17, 2011)

And here is a great video that i just found where GM shows how the volt system works:

https://www.youtube.com/watch?v=AX5ZwzNwTc4

Much better job then I would have done with some shaky camera video pointing at things under the hood.


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## Moltenmetal (Mar 20, 2014)

Wow, you're made of stouter stuff than I am- that drivetrain is frighteningly complex based on the video...


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## kerrymann (Feb 17, 2011)

Moltenmetal said:


> Wow, you're made of stouter stuff than I am- that drivetrain is frighteningly complex based on the video...


Not really. Take the engine out of the mix and you only have 2 modes and there is nothing that says that you can not just operate in one mode.

I started this for the battery and the price for the rest was too good to pass up. Trying to get the inverter and motor is a long shot but rewards are not without risk.


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## aeroscott (Jan 5, 2008)

Great stuff, This is state of the art.


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## jddcircuit (Mar 18, 2010)

kerrymann,

Are you sure that the Volt inverter interface is CAN bus only? The Prius inverter/motor that I am using does not use CAN bus and hacking it is very different than just CAN decoding.

Have you come across a wiring diagram of the Volt? This might give some insight into the interconnections and type of hacking required.

Thanks
Jeff


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## kerrymann (Feb 17, 2011)

jddcircuit said:


> kerrymann,
> 
> Are you sure that the Volt inverter interface is CAN bus only? The Prius inverter/motor that I am using does not use CAN bus and hacking it is very different than just CAN decoding.
> 
> ...


No I am not sure at all. That is in fact my biggest concern. I have not found any wiring diagrams yet but right now I am focused on the battery. I am worried that the only way to get it work is if it can communicate with all of the other controllers on board. You see this a lot in engine swaps and it is can be a mess unless you can reflash the ECU.


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## CKidder (Dec 12, 2009)

kerrymann said:


> No I am not sure at all. That is in fact my biggest concern. I have not found any wiring diagrams yet but right now I am focused on the battery. I am worried that the only way to get it work is if it can communicate with all of the other controllers on board. You see this a lot in engine swaps and it is can be a mess unless you can reflash the ECU.


The way the Prius (at least the older 2004 version jddcircuit has) works is dead stupid. I cannot imagine how anyone could make a setup like that and sleep at night. The Toyota engineers should be ashamed. I also cannot imagine that a nearly new Volt would work like that at all. CANBus control of vehicle hardware is very common these days and would be a fairly reasonable guess. Canbus works over two wires and at very low voltage (around 0 to 1.4V differential between the wires). Unfortunately, without a schematic it could be interesting to find those two wires if they even exist. They would likely be twisted together and needn't be very large. 

If it is canbus controlled (and I'd be 90% sure it is) then I just might know somebody who likes to hack on canbus controlled hardware. The hardware and software exist but tend to be expensive. There are, however, people who are working to change that. 

What I'm really trying to say is: I helped build a replacement ECU for electric cars and I've also been turning that same ECU into a reverse engineering tool to crack new hardware. After the comm scheme is reverse engineered the same ECU used for the reverse engineering is then re-flashed to actually drive the hardware. This should save time and money and lead to less wasted hardware.


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## jddcircuit (Mar 18, 2010)

CKidder said:


> The way the Prius (at least the older 2004 version jddcircuit has) works is dead stupid.


blessing to some curse to others


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## kerrymann (Feb 17, 2011)

piotrsko said:


> http://www.lem.com/docs/products/dhab%20s44.pdf
> 
> heater is in input coolant manifold, orange 2 wire plug about 1/8 dia pins
> 
> ...


Thanks!



CKidder said:


> The way the Prius (at least the older 2004 version jddcircuit has) works is dead stupid. I cannot imagine how anyone could make a setup like that and sleep at night. The Toyota engineers should be ashamed. I also cannot imagine that a nearly new Volt would work like that at all. CANBus control of vehicle hardware is very common these days and would be a fairly reasonable guess. Canbus works over two wires and at very low voltage (around 0 to 1.4V differential between the wires). Unfortunately, without a schematic it could be interesting to find those two wires if they even exist. They would likely be twisted together and needn't be very large.
> 
> If it is canbus controlled (and I'd be 90% sure it is) then I just might know somebody who likes to hack on canbus controlled hardware. The hardware and software exist but tend to be expensive. There are, however, people who are working to change that.
> 
> What I'm really trying to say is: I helped build a replacement ECU for electric cars and I've also been turning that same ECU into a reverse engineering tool to crack new hardware. After the comm scheme is reverse engineered the same ECU used for the reverse engineering is then re-flashed to actually drive the hardware. This should save time and money and lead to less wasted hardware.


Sounds good to me. What to work on one for a volt? I am still trying to get a hold of a wiring diagram and hopefully it is all canbus but we will see. I have been busy in the barn dealing with permit issues upgrading my barn with 100amp service but that is another story.

Looks like Jack posted parts of my videos on EVTV but there wasn't much lead in. I was hoping that would help get people interested in cracking the wiring of the inverter but I think he has more projects then can handle as it is.


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## CKidder (Dec 12, 2009)

kerrymann said:


> Sounds good to me. What to work on one for a volt? I am still trying to get a hold of a wiring diagram and hopefully it is all canbus but we will see. I have been busy in the barn dealing with permit issues upgrading my barn with 100amp service but that is another story.
> 
> Looks like Jack posted parts of my videos on EVTV but there wasn't much lead in. I was hoping that would help get people interested in cracking the wiring of the inverter but I think he has more projects then can handle as it is.


The Volt may or may not have multiple can buses. I'm told that the Leaf has three of them. The GEVCU hardware is intrinsically capable of connecting to two buses at once. So, what's left is to figure out how many buses the Volt uses and where they are. Almost certainly at least one exists and is on the OBDII connector. So, that's a start.

I'm actually working on making an Arduino IDE capable canbus to USB dongle. It will essentially be a modified copy of the GEVCU hardware but without the hardware I/O and significantly cheaper. My initial plan is to have it under $100 and still be galvanically isolated and dual bus. So, that gives another option for monitoring. The bonus with that idea is that you don't need to repurpose a big ECU for reverse engineering. Also, the little dongle will have a DB9 connector and multiple plugs will be possible. This will allow for using it on a Leaf with the proper plug or a Volt with the proper plug, etc. 

Yes, Jack has a lot of projects and it seems like he's backed off of the vehicle reverse engineering a bit but I haven't so we're still a go. Without his support the process might be a bit slower but it'll get figured out. And, if such things start producing fruit it'll make it more enticing for him as well.


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## kerrymann (Feb 17, 2011)

According to people on the volt forum, these guys are supposed to have wiring diagrams for the volt but I have been trying to sign up for a account for the past week with no luck:

http://www.autocats.ws


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## dotrick (Sep 4, 2014)

Hello,

I bought a Chevy Volt Battery too... I'm looking for some informations about the CAN Bus and BMS.
Do you have an electrical schema to switch on the BMS and read messages on CAN BUS?


Thank you


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## crashedup (Oct 28, 2008)

Hello! this is a message to the moderators! 
There should be a new title in the forum for hacking oem ev's, where everyone who has tried or has info on oem ev parts, because that is our future as DIY. It is the cheapest route out there and we end up with high qulity parts from junk yards for peanuts! 
Example; I called around and a battery pack out of a volt or leaf goes for around $2000, and that's without negociation because they have no idea what to do with the stuff! Imagin if we could use everything from a leaf or volt, motor, charger, battery. We could make a sub $10,000 quality ev!


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## kerrymann (Feb 17, 2011)

Hey all,
Sorry for the lack of updates. I realized I haven't posted anything here but I did crack a lot more into the volt pack and started putting up more videos of what I found along with progress on the e30:

https://www.youtube.com/user/d55guy/videos

I will be putting up more this weekend. 

I am working with Jack's group on reverse engineering the components taking captures from my 2013. They gave me a candue and it is a bit of a learning curve on the CAN but things are progressing. It really helps having my volt that I can use to sniff the canbus while doing specific operations.

I have spent most of my time on the battery side. I have stripped down a few packs and developed my own mounting system. I was so anxious to test it all I pulled the enerdel that I just put in my e30 and put in most of a volt pack and wired it all up to my Soliton1. If I can get a throttle figured out this weekend I hope to take it for a test spin.


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## eldis (Sep 3, 2013)

kerrymann said:


> Hey all,
> Sorry for the lack of updates. I realized I haven't posted anything here but I did crack a lot more into the volt pack and started putting up more videos of what I found along with progress on the e30:
> 
> https://www.youtube.com/user/d55guy/videos
> ...


Thanks for the work you're putting in the videos!
I'm just going through the videos related to the battery - you got some things a bit wrong, so I would like to clarify it (didn't finish watching it all yet).

Battery interface module:
- The big ceramic white resistors are not heaters, they are precharge resistors. They are used together with a precharge relay (one of the small relays) and a MOSFET PWM, to ramp up the voltage before the main contactor turns on (so you don't get any sparking).
- One of the water connectors contains a HV heater (working from a pack voltage), again, controlled by one MOSFET
- All precharge, heater and contactors can be controlled externally, not using BMS module (it does not interface to it at all). Using X1 and X2 external connectors

I did reverse engineer most of the Chevy Volt drivetrain, but I'm still analyzing bits here and there, so I didn't want to release an incomplete documentation. Write me a PM if you want to cooperate on it.


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## kerrymann (Feb 17, 2011)

eldis said:


> Thanks for the work you're putting in the videos!
> I'm just going through the videos related to the battery - you got some things a bit wrong, so I would like to clarify it (didn't finish watching it all yet).
> 
> Battery interface module:
> ...


Duh, precharge resistors. Of course, it's obvious now. I was looking for a heater and saw those and jumped to the wrong conclusion. I will correct it. Thanks. 

There are a couple other things I need to change or update in the videos. I find myself having time to work on the cars, or shoot videos, or edit the stuff, but not the time to do all of them. I tried having a family friend with the video editing (hence the goofy intros) but it did not work out.

Anyway, I will send you a PM. There is already a group of about a dozen of us working on the volt and the leaf and the more the better


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## piotrsko (Dec 9, 2007)

Heater is in the passenger side water cooling manifold. 2 pin Orange connector going to relay module ( I think, mine is scattered). 

Relays are good for average 10 amps on the small, 350-400 amps on the big mains, 600ish break on a one shot over current event. Nice panasonic hydrogen suppressed contacts which disassemble using a torx

Flat oem wires good (so far) 250 amp. I got nervous and yanked them.

Current sensor between module 1 & 2 is a 2 part hall sensor good to 400 amps or 20 amps. Rubber center plug. Offset is 3.80, voltage declines to 0. I am running it on 5 vdc, goes to 12. Building an inverted opamp to drive my jdh 404.


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## ElementalEnergy (Feb 6, 2015)

Hey folks. We are getting ready to purchase a Chevy Volt battery pack from a pretty new wrecked volt (was hit in the front). Since they just got the whole car in, we were wondering if there are any other bits and pieces that it might be worth pilfering from the car. Cooling pumps, contactors, heater etc?? 

Thought you all might have some insight after digging around in these parts for awhile. Any bits and pieces that might be nice to have around for our build? Thanks so much for putting in all that work!

Build thread here:
http://www.diyelectriccar.com/forums/showthread.php/planning-1985-vw-doka-conversion-140210.html


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## piotrsko (Dec 9, 2007)

Depends on how you get the car. If it is your car with complete access, then everything you might think you need. If it is their car and you are buying parts that they yank, power steering pump, battery coolant pump, battery charger control module, A/C compressor pump, both ends of any harnesses for the modules you buy. All the contractors that are worthy are in the battery, everything else is CAN controlled. The wrecking yard is going to hacksaw or cutting torch stuff out, cut harnesses, and just generally booger up the removal unless you are there to supervise. Make sure you get the disconnect safety inert plug from the top of the battery, I hear chevy is prissy about selling replacements.

GET THE VIN # !!!!!! That helps the dealership sell you stuff.

BTW us old guys call that a combi


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## kerrymann (Feb 17, 2011)

Besides the obvious stuff get the charger on the passenger side front bumper if It is not damaged (Often it is). It has been hacked and its a nice unit. 

There is the DC DC converter in the trunk which can put out some serious power. 
The J1772 inlet is a good quality one. Check the truck for a 110v charge cord. The volt has EPS so useless you can make the whole rack work the power steering won't be easily used. The heater is a good one too and I just picked one up to start hacking (100 bucks). I would pick up the coolant pump and heat exchanger for the battery system. Definitely get every wiring connector for every part you buy withth a min 6" pig tail.


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## kerrymann (Feb 17, 2011)

I got a round to putting up some more videos. People kept asking me about how and where to get them:

https://www.youtube.com/watch?v=RbcbhGPp2PQ

And also I got some good information about the power capability of these volt packs courtesy of the DOE:

https://www.youtube.com/watch?v=HYrhykqpyj4

Sorry in advances as they are kind of long an rambling but if I waited around to edit them they would never get posted (not unlike the other hours of video sitting on my hard drive)

I hope they are helpful,


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## agent005 (May 3, 2015)

eldis said:


> Thanks for the work you're putting in the videos!
> I'm just going through the videos related to the battery - you got some things a bit wrong, so I would like to clarify it (didn't finish watching it all yet).
> 
> Battery interface module:
> ...


Hello eldis, you seem to know a lot about the volt and its internal workings quite a bit, I was wondering if you could help me out with a restoration project involving a wrecked (poor thing should have actually been totalled) 2012 chevy volt. 

I have completely rebuilt the car and am having an issue with the precharge relay contactors (GM service procedures have directed me to replace the junction block relay which contains the high voltage contactor pack, which I have done. (cost me $768 bucks and apparently they have sent me a dud) I cannot get a return/exchange because they apparently dont do returns on electric componets and its outside of the 30 day window, I have emailed them asking anyway with my fingers crossed  (awaiting a response)

The reason for replacing the junction block relay/contactor assembly is due to the fact that during any collision involving deployment of the airbag systems creates a high current condition in which can potentially damage the internal contactors in the junction block, service procedures direct replacing the contactor assembly/junction block relay as one of the first things to do.
I have done that, and still did not work, so i proceeded to do circuit/system testing and have concluded that the replacement relay/junction block they sent me must be a dud. 

I was wondering rather than shelling out more big bucks for another contactor assembly if you could tell me or show me where the precharge relay is and what should be the output voltages once the relay is energized inside of the contactor assembly? I can attempt to replace the relay itself with an aftermarket version and get the car back on the road.

much appreciated! I'd be happy to throw you a bone for it too


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## eldis (Sep 3, 2013)

agent005 said:


> Hello eldis, you seem to know a lot about the volt and its internal workings quite a bit, I was wondering if you could help me out with a restoration project involving a wrecked (poor thing should have actually been totalled) 2012 chevy volt.
> 
> I have completely rebuilt the car and am having an issue with the precharge relay contactors (GM service procedures have directed me to replace the junction block relay which contains the high voltage contactor pack, which I have done. (cost me $768 bucks and apparently they have sent me a dud) I cannot get a return/exchange because they apparently dont do returns on electric componets and its outside of the 30 day window, I have emailed them asking anyway with my fingers crossed  (awaiting a response)
> 
> ...


Hi agent005, I don't fully agree with that procedure in the service manual.

If the relay/junction box is the one sitting in front of the battery box, there is no need to replace it after crash. Many of us bought a pulled battery pack from a crashed Volt, and nobody reported any problems with this module (truth is, not everyone is using it..) Of course it could happen, that these contactors die as they are opened under the load (crash event). Normally they are opened in steady state condition with no current, to protect contacts. These modules can be easily tested, if you have some basic equipment available. On the connector X1 and X2 (round multipin on the module down) there are several relays that you can turn on by simply bringing 12V to them. Then you just measure with a multimeter if you do get voltage on the output (or you pull the module out and test it without the HV pack). You need to open both big relays at the same time to get HV on the output. Be careful when doing this, as you will have 400V exposed very close to your hands.










I had a better document that I've written for this, but can't find it now. Write me a PM if you want to help with the troubleshooting, so we don't spam this thread.


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## YogaSlackerSam (Jul 20, 2015)

hey Chevy volt Gurus,

Wondering if it is possible to put 5 volt battery packs together to get a 90kwh pack?

We are building a 4x4 overlander micro house and looking for 100 mile range for a 7000 pound aerodynamically challenged rig.

thanks in advance.

Sam


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## TexomaEV (Jul 26, 2007)

Great photos, What progress have you made since ? I would love to know if one could purchase a GM Tech2 Scanner w/TIS2000 access and tune/change various programming parameters within the Volt. Or some other similar, maybe less expensive tuner.


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## elcapitansd (Jan 17, 2016)

Hi Guys, 

This drivetrain looks nice for $1K - comparable to a replacement motor. What do you think of dropping the entire thing into a nice kit car of a porsche or something with regen braking? Thoughts? I am on the Mexican Border here in San Diego and we could easily start a small time customized volt drivetrain kit car operation. Labor Costs at $500/mo per factory worker. 

Thank You,

Steven, a tinkerer who got sidetracked by getting an MBA


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## Sarex (Mar 8, 2016)

kerrymann said:


> Duh, precharge resistors. Of course, it's obvious now. I was looking for a heater and saw those and jumped to the wrong conclusion. I will correct it. Thanks.
> 
> There are a couple other things I need to change or update in the videos. I find myself having time to work on the cars, or shoot videos, or edit the stuff, but not the time to do all of them. I tried having a family friend with the video editing (hence the goofy intros) but it did not work out.
> 
> Anyway, I will send you a PM. There is already a group of about a dozen of us working on the volt and the leaf and the more the better


I would love to join! I just got half of a volt battery (the end-two 72v/54s modules), a front relay module as well as a control module (HIGH VOLTAGE BAT Volt 24 Channels). I'm looking around for an ECM and am definitely interested in haxoring the CAN interface. Send me a PM if interested/possible.

Also let me say you have some Great videos!!! The the VanHalen logo on the battery ends, I would Pay good money for ends like that!! I would be interested in learning more about the bolt sizes you need for the bolts?

I'll be studying your videos alot.  Thanks for them!!
Kris


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## brianbri6 (Apr 3, 2013)

I would like to help on the project where ever I can. I have a 2012 Volt with GDS2 software and MDI module. I am going to get a Y adapter for the OBD port so I can sniff traffic with a OBDMX bluetooth adapter while running diag. I also have the service manual.


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## skeyes (Dec 3, 2016)

kerrymann said:


> Besides the obvious stuff get the charger on the passenger side front bumper if It is not damaged (Often it is). It has been hacked and its a nice unit.


OK this is awesome. I was just thinking about what I should do for a charger... I am planning on using chevy volt battery packs for my rx8 conversion. 

Where can I find the hack information on the chevy volt charger?? What hardware do I need to get it to work? 

Thanks for any info you can give!!

I watched your vids on the volt battery BTW and I am convinced to go that route. The performance and the savings over LifePO4 is too good to pass up. 600KW should be enough lol


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## brianbri6 (Apr 3, 2013)

you need to sign up to view post but here is the link to info on the volts onboard charger and how to command it on and set voltages.
http://forums.evtv.me/post/chevrolet-volt-lear-charger-7207301?pid=1292541185


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## jontscott (Apr 28, 2016)

Well I guess it depends how much C code you want to write... EVTV seems to sell their CANDue (modified Arduino clone it seems) that they use to control all sorts of CAN Bus devices. I have never used one so I cannot say much beyond that.

On the form link above people shared some CAN Bus captures of the Chevy Volt changer working, and it seems all the information is there to write your own software with full control. What feels like forever ago I parsed over the CAN data on the form and felt there was more useful data to be decoded but as no one ever replied I guess either that form is dead, I am wrong, or no one really cares... Personally I wish there was a site with CAN dumps that I could browse through and analyze since I find that fun, (I know there are things wrong with me )


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## notAhoser (Mar 28, 2017)

Does anyone have any logs of communications with the cell monitors/managers that are located on the battery packs on a Volt? I picked up a complete 2013 Volt battery and I'd like to use the cell monitors. I'm not using the Volt charger equipment, either. 

I am using a USB to CAN interface and Wireshark for haxors and I can see lots of broadcast info, but I don't have a Volt to sniff to see the commands going back to the cell monitors. I don't think the CAN lines from the pack modules are passed through to the main chassis CAN lines (2500/2501), so someone would probably need to tap into the lines on the battery pack itself. I can do this, but I don't have a Volt and I think that might be a real challenge to get to.


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## notAhoser (Mar 28, 2017)

Well I spent a few hours logging all the CAN buses I could identify on a 2012 Volt tonight. I haven't done much with the data yet, it's time for bed. The files are too big to attach on a forum post so I'll upload them and post them tomorrow.


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## notAhoser (Mar 28, 2017)

I'll drop this here in case anyone really wants to get into it. These are 3 giant logs exported as a CSV from Wireshark. I had to split it up into 3 files because there are 2.5 million messages, nothing filtered out. This log was taken from the AUX DLC port CAN bus that's connected to the HPCM2 and charge controller (2012 Volt). I grabbed logs from all the other ports in various conditions, I'll post them as I get through them.

For this log, we got in the car, I started logging and there was no activity. The car was removed from the charger in the minute before we started. I started the log, then we turned the car on and drove around to use up some charge. The dash indicator said we used 1.5kwh. Still logging, we pulled in to park, shut it off, let activity stop on the bus. 

Then we plugged the charger (L2) in and let it charge until all bus activity stopped when the car was fully charged, about 30-40 minutes. This bus has continuous activity during the charge, but otherwise nothing when the car is off. I checked all of the other CAN busses on both DLC's and they all have a short burst of messages when the charger is first connected, but then stops completely. They have nothing continuous during the actual charging phase.

https://www.dropbox.com/s/mfbh3w7d68sp3ux/Volt_LOG_11.zip?dl=0


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## Anymouse (May 7, 2017)

Have the CAN logs from a full Volt been posted anywhere? I'd love to help with this. In the process of acquiring a used Volt pack for a solar project, and I have a lot of spare time to dig into CAN hacking the onboard BMS.

Based on
http://www.edn.com/Home/PrintView?contentItemId=4391497
https://docs.google.com/file/d/0BwHvhEbCHHEleUp3TUMxOUwzdmM/edit

It seems like the data that's most interesting is between the Battery Energy Control Module on the front of the pack, and the Battery Management Module under the passenger seat.

(edit)
Oh hey, found elsewhere on this forum that this is actually pretty easy if you're using the whole battery pack at it's full voltage:
http://www.diyelectriccar.com/forums/showpost.php?p=842810&postcount=544

Because I plan to split these up into parallel 48V units for solar, I think I'll still dig into the module communication itself though.


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## notAhoser (Mar 28, 2017)

Anymouse said:


> Have the CAN logs from a full Volt been posted anywhere? I'd love to help with this. In the process of acquiring a used Volt pack for a solar project, and I have a lot of spare time to dig into CAN hacking the onboard BMS.
> 
> Based on
> http://www.edn.com/Home/PrintView?contentItemId=4391497
> ...


The logs are posted, yes. They are large, so be patient... https://www.dropbox.com/s/mfbh3w7d68sp3ux/Volt_LOG_11.zip?dl=0 This file contains 2.5 million CAN messages logged on the HV CAN bus. It starts just sitting with the car off, then we go for a 15 minute drive, then plug it in to charge to 100%.

The modules - BECM is in the battery pack and the HPCM2 is under the passenger's seat. Charging, balancing, and the like are actually commanded by the HPCM2, not the BECM. The cell voltage, temps, current sensors, and a couple other things have been figured out. What I still haven't found is what the HPCM2 sends to the BECM to tell it to balance cells.

But I'm going to figure it out. I bought the HPCM2 from the actual Volt my pack came out of on Friday and I will try to get it fooled. The have a feeling the balancing command(s) are rare since the packs are so consistent.


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## Anymouse (May 7, 2017)

Perfect, thanks! 

Based on that other forum post by jontscott, I looked into 0x202 etc. for the individual cell voltages and could definitely spot them in there. I searched high and low and couldn't find anyone's info for parsing the bits - so here's what I could reverse engineer myself from scratch (in case anyone else finds this).

Grab CAN IDs 0x200, 0x202, 0x204, and 0x206. Parse out the bits like this: 

3 - ignore
12 - cell voltage A
4 - ignore
12- cell voltage B
1 - ignore
12 - cell voltage C
7 - packet number
10 - ignore

Each CAN ID sends 8 packets, (packet number 0 through 7), and each packet has three voltages. There's four CAN IDs, so 4 * 3 * 8 = 96, which is the number of cell sets in the Volt pack.

It's a total guess, but if you divide the cell voltage values by 800 - you get what looks a lot like the actual figure. This could be wrong! I don't have a volt pack to double check with a voltmeter. But from what I can tell 4.06V is fully charged, so that number works out with this CAN dump.

Here's an annotated snippet of my raw dump, with iterative parsing:


```
Timestamp   Can ID  ign   voltage A   ign    voltage B     voltage C   pktnum   ignore         vA     vB     vC  p        voltA voltB voltC
3400.101046  [200] [000 110010110110 0111 110010110101 0 110010110110 0000001 1100000000 ] [0 3254 7 3253 0 3254 1 768 ] [4.068 4.066 4.068 ]
3400.101254  [202] [000 110010110101 0111 110010110100 0 110010110101 0000001 1100000000 ] [0 3253 7 3252 0 3253 1 768 ] [4.066 4.065 4.066 ]
3400.101490  [204] [000 110010110101 0111 110010110101 0 110010110100 0000001 1100000000 ] [0 3253 7 3253 0 3252 1 768 ] [4.066 4.066 4.065 ]
3400.101727  [206] [000 110010110101 0111 110010110010 0 110010110101 0000001 1100000000 ] [0 3253 7 3250 0 3253 1 768 ] [4.066 4.063 4.066 ]
3400.126331  [200] [000 110010110100 0111 110010110110 0 110010110101 0000010 1100000000 ] [0 3252 7 3254 0 3253 2 768 ] [4.065 4.068 4.066 ]
3400.126554  [202] [000 110010110101 0111 110010110101 0 110010110101 0000010 1100000000 ] [0 3253 7 3253 0 3253 2 768 ] [4.066 4.066 4.066 ]
3400.126792  [204] [000 110010110101 0111 110010110101 0 110010110110 0000010 1100000000 ] [0 3253 7 3253 0 3254 2 768 ] [4.066 4.066 4.068 ]
3400.127041  [206] [000 110010110101 0111 110010110100 0 110010110100 0000010 1100000000 ] [0 3253 7 3252 0 3252 2 768 ] [4.066 4.065 4.065 ]
3400.151142  [200] [000 110010110110 0111 110010110101 0 110010110110 0000011 1100000000 ] [0 3254 7 3253 0 3254 3 768 ] [4.068 4.066 4.068 ]
```
And here's a CSV of what all your 96 of your cell voltages looked like throughout that entire dump (every 100ms or so!). http://scrunk.com/volt-cell-log.csv.zip

I'm going to keep digging in here and see if I can find other useful IDs. I think you're right about balancing though - it may not start until it sees a cell out of whack, so the only way to catch it in the act might be to manually bleed down one cell by 0.1V or so and see if we can cause it to send the balance command.

Also I am very interested in seeing if your HPCM2 works as expected when it isn't part of the rest of the car. If that goes properly, I would love to get a capture from the 125kbps CAN bus between the BECM and the modules themselves. That'd allow folks to split them up and use them for solar without having to keep the whole pack intact at high voltage, and also avoid getting a pricey third party BMS.

edit:

To keep all the info in one place, I'll just put CAN IDs here as I find them:


```
=== Confident ===
0x200:   3, 12, 4, 12, 1, 12, 7, 10    ???, cell voltage, ???, cell voltage, ???, cell voltage, cell bank number, ???
0x202:   3, 12, 4, 12, 1, 12, 7, 10    ???, cell voltage, ???, cell voltage, ???, cell voltage, cell bank number, ???
0x204:   3, 12, 4, 12, 1, 12, 7, 10    ???, cell voltage, ???, cell voltage, ???, cell voltage, cell bank number, ???
0x206:   3, 12, 4, 12, 1, 12, 7, 10    ???, cell voltage, ???, cell voltage, ???, cell voltage, cell bank number, ???
0x212:   13, 10, 8, 8                  charger HV current (/20), HV voltage (/2), LC current (/5), LV voltage (/10).   

=== Guessing ===
0x210:   12, 2, 10, 3, 12, 4, 19    pack voltage (/8), ???, main pack amps? (/10), ???, amperage again? (/20), ???, ???
0x264:   4, 12             	    ???, minutes since last full charge (/2)
0x304    8, 8, 8           	    ???, charge HV current (/20), ???
```


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## notAhoser (Mar 28, 2017)

You've got that stuff down. There's a few other things in that log that I should be able to finalize this weekend. There is a coolant temp in and out of the pack as well as the average cell temp of the pack. You can see the individual temps on the 125k bus between the BECM and BICMs. I might get time to connect the HPCM2 and see what it does this weekend, but I've been pretty busy with other things so no guarantee!


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## Anymouse (May 7, 2017)

No worries, thanks for the help! I've got a 2014 Volt pack including HPCM2 on its way up to me, but it'll be a couple weeks at least (has to clear customs into Canada). Once I get it I can start digging into this as well.


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## Anymouse (May 7, 2017)

So I discovered that the HPCM2 isn't necessary in order to get the cell voltages out of a standalone Volt battery. You just to hook up to the bottom connector of the BECM module inside (K16 connector X1), with the following pins. If you're looking at the factory connector, numbering starts in the top right and moves left, they are the these colours:

1 - Black - Ground
2 - Red - 12V
3 - White/Black - CAN_Low
4 - Light Blue - CAN_High
9 - Black - Ground
14 - Brown/Red - 12V
15 - Orange/Yellow - 12V
16 - Light Green/Light Blue - 12V

This sets the Accessory Wake-Up Serial and Communication Enable lines high, and causes the exact same data you sent me in the log file to get thrown out the CAN lines on 3 and 4. That's all I need for this project (Solar Install) for now, but it would be awesome if someone could catch the battery balance command in the act from the HPCM2 (maybe by drawing down one cell while capturing the CAN traffic).

For now I am going to just build a system to let me see the cell voltages and alert me if any drop out of spec, then I'll go in and manually balance the cells.


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## notAhoser (Mar 28, 2017)

Anymouse said:


> So I discovered that the HPCM2 isn't necessary in order to get the cell voltages out of a standalone Volt battery. You just to hook up to the bottom connector of the BECM module inside (K16 connector X1), with the following pins. If you're looking at the factory connector, numbering starts in the top right and moves left, they are the these colours:
> 
> 1 - Black - Ground
> 2 - Red - 12V
> ...


I still haven't messed with the HPCM2... Cells out of balance is probably a pretty rare occurrence, but I had 3 cell groups that were really low in one pack, so it would have been a good time to test.


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## Caps18 (Jun 8, 2008)

I wonder if it would be possible to move all of the components from a totaled Volt into a donor vehicle (if the motor and batteries work)? As long as it can mate to the transmission or drive shaft, it should work.


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## rmay635703 (Oct 23, 2008)

http://ecomodder.com/forum/showthread.php/1946-chevy-prius-truck-34935.html

You mean like this?


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## jimmyaz (Oct 9, 2017)

Hi All, 

Could anyone tell me which one of the relay that's in front of the battery that I can use for a LVD (low voltage disconnect) or HVD (high voltage disc) for my solar application?

I got the 2013 chevy volt battery for my solar application. For safety I would like to have a HVD between the solar panels and my charge controller, shutting off solar power to the charge controller incase of a runaway. 80volts at 30amps. For the LVD between inverter and battery is 48volts and max out at 250amps (but probably never be that much, more like 100amps.

Which relay can I use out of the battery?

thanks


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## Duncan (Dec 8, 2008)

Hi Jimmyaz

You will find two large contactors and three small ones
The Volt uses the two large ones at 390 v and about 300 amps - but they did not like me putting 1200 amps through them

The three small ones are used at 390 v - but only 10 amps or so

I would use the small ones on your 80v and the two big ones on your 250 amps


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## jimmyaz (Oct 9, 2017)

Duncan said:


> Hi Jimmyaz
> 
> You will find two large contactors and three small ones
> The Volt uses the two large ones at 390 v and about 300 amps - but they did not like me putting 1200 amps through them
> ...


Thanks

A couple of page back someone mention that the big contractor are only for one time use if switched under load it might burnt? I wonder if they can be use regularly at 48v and 100amps max?

Are they normally "open", close when 12v applied?

Another thing is I'm going to have to figure a way to COOL the battery in summer (110F in my garage when it's hot). Is it safe to use regular water in the battery instead of the cooling fluid that it came with? Any idea guys?


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## Duncan (Dec 8, 2008)

Hi Jimmy

Would you be opening/closing under load? - why?

Battery water
I'm using water/antifreeze mix - car antifreeze has corrosion inhibitors
You can see how I got the air out on my build thread

110F is 43C 
You should be looking at keeping the battery to 30C - 35C - the problem here is getting it up to that
Your garage is 43C - what is the air temperature outside?


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## jimmyaz (Oct 9, 2017)

Duncan said:


> Hi Jimmy
> 
> Would you be opening/closing under load? - why?
> 
> ...


Hi Duncan, 

Yes, the relay would have to be under load all time and it could be 10amps - 100amps. The idea is for these relay to shut off power from solar to solar charge controller to prevent a overcharge in case the charger malfunction. For the inverter disconnect, it's to protect the battery from over discharging. All though the inverter already have cut off that can be set, but this is a SAFETY redundancy I want.

Arizona is the perfect place for Solar, sunshine 340days a year. But in the Summer, the heat scorching is outrageous... high ambient can peak to 125F = 51C. If so, my Garage can get to 110F, mostly the garage would be between 90-105F (32-40C).

Even with water cool, I am thinking I'm going to have to run this water through something that cool it.. .otherwise ambient water temp would still be above 90F (render useless). 

Currently my AGM battery box is hook up to a tiny mini fridge that run a few hours a day to keep it cool. Maybe I can do the same if the water cooling is too complicated. But I always thought having coolant flow through every single cells is much better than cooling a entire batter box space.

thanks for all the advise.


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## Duncan (Dec 8, 2008)

Hi Jimmy

As the contactors are back-up they won't be opening/closing all of the time - I'm pretty sure that they are good for 10,000 + cycles at those sort of currents - the only thing I would check is for capacitors
Both the charger and the main invertor on EV's have large capacitors so they are initially connected through a resister to limit current - called "Pre-charge"

As far as cooling is concerned use your fridge and have a copper water coil inside it
I'm using one of those solar water pumps
You won't need to cool it for the heat the batteries are producing - just the heat it gets from the surroundings so some insulation will help a lot


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## jimmyaz (Oct 9, 2017)

Duncan said:


> Hi Jimmy
> 
> As the contactors are back-up they won't be opening/closing all of the time - I'm pretty sure that they are good for 10,000 + cycles at those sort of currents - the only thing I would check is for capacitors
> Both the charger and the main invertor on EV's have large capacitors so they are initially connected through a resister to limit current - called "Pre-charge"
> ...


Hi Duncan, 

You lost me there on the capacitor set up... I tore the contact apart and pull the two big one out. Do you think I can use it without any precharge?

So these are normally "open circuit" unless power by a 12v source to the coil right? Any idea how much power it uses and how can I know which positive and negative for the coil wire?


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## Duncan (Dec 8, 2008)

Hi Jimmy
Now that you have the contactors out - look up the specs on the web to confirm direction of voltage
I think that they are just coils with no inbuilt diode so they don't care

Pre-Charge
The problem with coupling something with a big capacitor to a high voltage source is that you get a LOT of inrush current - as in hundreds of amps

This is only when you couple up an empty capacitor
The solution is to have a resistance in series
So you switch on with one contactor but with something like a kettle element in series - then after the voltage is most of the way up you use the other contactor to "short out" the resistor 

You can't use an ordinary resister as you do want to charge the capacitor quite quickly so you do want a reasonable amount of current (5 or 10 amps?) and that will blow up one of those little resisters

A kettle element is ideal and you can probably rob one from a dead kettle - or water heater


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## piotrsko (Dec 9, 2007)

If you have a complete volt pack there two white "power" resistors that chevy used for precharge. Probably 10 watts rated. I forget the resistance.


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## jimmyaz (Oct 9, 2017)

According to this datasheet, I think the two big relays are only rated for 120A.

https://www.google.com/url?sa=t&rct...h_eng_ev.pdf&usg=AOvVaw04v3S42RRQNedT3X7ThtW2


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## bilbo (Oct 31, 2017)

Has anyone had success controlling the 2 main contactors and the smaller relays in the battery header through the Can bus. Now that the charger, heater, dc-dc converter and parts of the BMS are working a complete electrical system using the stock devices is close.

Also I cannot find an off-grid 400 VDC to 120 VAC inverter (preferably in a 2kw range). If anyone can point one out I would greatly appreciate it.


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## Duncan (Dec 8, 2008)

bilbo said:


> Also I cannot find a 400 VDC to 120 VAC inverter (preferably in a 2kw range). If anyone can point one out I would greatly appreciate it.


Have a look at solar power inverters - mine operates at about 400v DC


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## aeroscott (Jan 5, 2008)

weberauto on youtube just disassembled the volt power inverter 1000 amp and 650 volt rating ,2 of these units in the box, overbuilt . why can't it switch at 10khz instead of 2khz making it 3 phase ups/inverter. More caps,snbubers what would it take.Drivers would be worked much harder.


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## bilbo (Oct 31, 2017)

I am looking at buying a gen-2 battery to be used as a full battery pack. A number of people (ex, post 54 on this thread) have the BECM Working with a standalone complete pack by powering the connector on the front of the battery.

Will this work on a gen 2 volt battery? If so what is the pinout on the battery connector? 
Finally is there a gen 2 service manual available on the web?


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## arber333 (Dec 13, 2010)

Weber transaxle dissassembly
https://www.youtube.com/watch?v=dqM3YXEf1js

Well since nobody is saying this...
If you got inverter and you got transaxle, batteries aside... you could use motor B to drive the wheels and just connect a Briggs&Stratton lawnmower engine to motor/generator A. Of course you would use flex coupling to dampen vibration. You simply leave clutch B off and only operate clutch A. Or weld it for that matter.... 

So when you run out of battery you start B&S motor and apply clutch A to bring say 8 - 10kW to inverter. 
Inverter could be run off of two Lebowski brains. One only in regen mode. 
Second driving motor B up to 70mph. TomDB sucessfuly operates BLDC motor using one Lebowski brain board.
http://www.diyelectriccar.com/forums/showthread.php/chevy-volt-opel-ampera-inverter-179922.html

No CAN bus needed that way and only You in control of operating B&S stinker .

5c dropping...


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## poleguy (Dec 12, 2017)

Anymouse said:


> So I discovered that the HPCM2 isn't necessary in order to get the cell voltages out of a standalone Volt battery.
> ...
> but it would be awesome if someone could catch the battery balance command in the act from the HPCM2 (maybe by drawing down one cell while capturing the CAN traffic).
> 
> For now I am going to just build a system to let me see the cell voltages and alert me if any drop out of spec, then I'll go in and manually balance the cells.


I'm planning to buy a volt pack to convert a civic. Your post is very encouraging. It seems from further reading (WopOnTour) that a balance event "occurs when the BMS measured voltage of any group/triplet exceeds the average voltage for the 96 groups being monitored"

http://gm-volt.com/forum/archive/index.php/t-129417.html

So the idea here of bleeding down one cell is backwards, and wouldn't trigger a balance event, you need to charge up one cell more than the others for it to happen. And it's triggered by the 'brain' module, so the whole pack must be together for it to happen.

So probably you don't have a pack still all together, right? If you or anybody out there has a Chevy Volt (or complete pack) that you can monitor the CAN bus, would you be willing to drive the pack down a bit and then charge up one cell more than the others and post a dump of the CAN BUS?


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## mons2b (Nov 17, 2015)

piotrsko said:


> Sensor is lem product dhab s44 a 0 to 600 amp inductive coupled DC. Runs on 5 v ref. Darn kindle won't paste the pdf here.
> 
> I'm lusting after modifications to the mains relays after I figure out what they break. 350 amp one shot perhaps.
> 
> Also many assorted imbedded thermocouple, and looks like a 600 watt heater element


I still have my current sensor. What circuitry do I need to use it? it would be neat to see the current reading from it. Ive seen Arduino boards. Is that the easiest way to use it?


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