openinverter forum

Finally getting around to making a build thread. I’ve been making slow, steady progress on this build for quite a while now. It continues to be a learning project for me as I didn’t have much automotive mech or any fab or electronics experience before this.

Let me know what questions you all have, other pics you’d like to see, or ideas/ suggestions. There are some design and build elements that I’m not too pleased with, but don’t have a better idea yet.

For me the biggest challenge by far has been dealing with the Model 3 modules: both BMS control, and packaging them strongly and securely into the vehicle. I lifted the truck in order to make room for the batteries between the body and frame. The long modules will fit like a glove under the bed and about 6" under the cab. The short modules will go below these, and further forward so that they are roughly equally below the bed and the cab. I've mostly finished the boxes for the long modules, haven't done much on the boxes for the short modules, and have partially completed a mounting system for the 4 boxes. I've both modified and fabricated new crossmembers that will support the battery boxes from above using threaded rod and crossbars. I think my current approach could use some improvements, both securing the batteries in their boxes, and securing the boxes within the vehicle. Would love to hear ideas and suggestions from you all!

As for the remainder of the build, I've Quaifed all over the LDU with new gearing and LSD, plus the trusty openinverter controller. I've got a prius accel pedal installed and prius power steering (not yet installed). I got driveshaft adapters made at the machine shop as you can see in the pics, but haven't had driveshafts made yet.

I've upgraded the rear springs to heavy duty, replaced front and rear diffs with LSDs, replaced the rear end with one with disc brakes (plus a SOA conversion), installed some junkyard electric fans on the stock radiator...

I haven't really taken apart the dash or interior yet; I plan to do that once I've got my batteries mounted.

are you going to get a plunging rear drive shaft made with a support bearing?

Bratitude wrote: ↑Mon Oct 10, 2022 3:14 pm are you going to get a plunging rear drive shaft made with a support bearing?

Yes, that’s the idea, a two-piece rear driveshaft with a carrier bearing mounted to the crossmember behind the LDU. The longer, rear section of the driveshaft will need a plunge or telescopic bit due to the solid axle suspension.

I mounted my LDU at an angle relative to the vehicle due to my front diff being off center over to the left. So while the output flanges are pointing in roughly the right directions, the angles aren’t all perfect, as in they don’t all add up to zero like in an ideal driveshaft scenario. Still don’t know if this mounting decision was a mistake or not. I’m hoping that some double cardan joints particularly in the front will do the trick. In my truck, mounting LDU at a slight angle actually allowed me to get it further up in to the transmission tunnel than if I’d mounted it straight.

Who’s got thoughts on mounting and BMS’ing the Model 3 modules? I really liked what SuperfastMatt did with his swap. My layout of the batteries in the vehicle will be very similar, but my current design has each module individually boxed. One problem I have is I didn’t buy the whole pack, so I dont have the full penthouse nor the structural elements from the pack like he does.

retrEVnoc wrote: ↑Sun Oct 09, 2022 11:01 pm As for the remainder of the build, I've Quaifed all over the LDU with new gearing and LSD

what is the gear ratio in the Tesla gearbox NOW? do you have 4.11:1 in bridges? what is the size of the wheels and what is the maximum speed you expect? I still can't mature enough to convert my hummer into an electric or a serial hybrid.

The Tesla gearbox is 4.5:1 IIRC

I swapped the diffs to 3.42 lsd and I have 31” tires but will likely end up moving to 3.08s and possibly larger tires to further increase my top speed and ,more importantly, slow down the motor cruising at hwy speeds

Damien’s ongoing truck build inspired me to get back on the forum and share my similar build! Long overdue update:

Drivetrain complete with modified LDU and custom driveshafts, and hopefully strong enough

All four Model 3 modules individually reboxed and installed

Openinverter model 3 BMS controller connected and showing bugs with the 23s modules. Tom trying to help debug but he needs a spare 23s BMB which I dont have.

6.6kW liquid cooled charger/ DC/DC installed

Vac system for power brakes installed

Reestablished LDU contactor control in the vehicle

Added a 12v fusebox from Nissan Leaf under the hood.

HV junction box mostly complete with ISH shunt, also have spare contactors for eventual Chademo charging.

Still need to finish 12v wiring

Questions for community:
Best guides for CANbus setup and configuring the components? Im clueless on CANbus. Dont know if any of my components have internal terminations. I know my charger does NOT.

ISH shunt wiring and setup? I downloaded the mfr documentation but still not exactly sure of myself

Does level II onboard charger (-) from battery (-) require going through the shunt?

VCU, I have a CANDue from EvTV which i thought i could maybe use as a VCU but not sure. Wasnt successful in loading GEVCU on it.

I have a contact on Facebook with bmb boards (you emailed me I’m guessing?) I’ll he’s on the ev conversion group as well. Ill message you with his contact

Bratitude wrote: ↑Mon Mar 24, 2025 8:27 pm I have a contact on Facebook with bmb boards (you emailed me I’m guessing?) I’ll he’s on the ev conversion group as well. Ill message you with his contact

Thanks! Yea please send me his info! Any luck with your BMS controller Brat? I think youre using the shortest Model3 modules, correct?

My build is so close to completion but I'm a little lost! I am working on building the CANbus and configuring the 'brains' of my vehicle but not sure the steps of the procedure.

Items to be on the CANbus:
Tesla LDU with OpenInverter board
Ovartech 6.6kw charger & DC/DC conv.
IVT-S Shunt
EVTV CANDue
EVBMW BMS Controller for Model 3 Battery Modules
Chademo Inlet Port
Volvo Power Steering Pump (non-critical, already works in failsafe mode)

I have a (non-CAN) AVC2 to manage the Level II charging protocol

My questions:
Is the CANDue sufficient to act as the 'brain' of the vehicle, given the above components?
How would I get a tablet set up to display the data from LDU, BMS, etc? The wifi signal from LDU is extremely weak inside the vehicle.
Once CANbus wiring is complete, how to configure the charger and BMS to level II charge?

I have documentation for most of the above components, but no experience with CANBus and only slight familiarity with Arduino IDE. Everything except the CANDue and BMS is installed, but I haven't fully built the CANbus wire harness yet. Vehicle High Voltage wiring is complete, 12v wiring is nearly done, and the vehicle does stop and go, but without BMS or DC/DC, can't do much more than that.

Thanks for any suggestions or references!

retrEVnoc wrote: ↑Sun Oct 05, 2025 9:03 pm Is the CANDue sufficient to act as the 'brain' of the vehicle, given the above components?

Sure, depending on what you want it to do. My LDU with OI doesn't have a single "brain", just individual controllers for specific things, and then me in the driver's seat to make decisions. If you want a more seamless experience, the CANDue should be able to do a lot, but obviously has some limitations.

That being said, based on what you have listed, you might want to look at Zombieverter instead. That can support CHAdeMO (since I don't see a controller listed) and is intended to interface between other OI based boards like your LDU board and BMS board. You might have to modify some code to support your charger, I don't know that one so I don't know how its set up. I believe Zombie can also handle the level 2 charging communication, so you wouldn't need the AVC2.

retrEVnoc wrote: ↑Sun Oct 05, 2025 9:03 pm How would I get a tablet set up to display the data from LDU, BMS, etc? The wifi signal from LDU is extremely weak inside the vehicle.

I would recommend you add one of these to your CAN Bus. Basically allows you to access the web interface, and since its not in the metal case of the LDU, it has much stronger signal strength. I added it recently and like having it. But I have not yet driven around with it showing readouts on a tablet, so I'll defer to other's experience there.

retrEVnoc wrote: ↑Sun Oct 05, 2025 9:03 pm Once CANbus wiring is complete, how to configure the charger and BMS to level II charge?

I'd start with the charger's manual for that.

Thanks for the info Manglesdorf! I know the Zombieverter would probably make this process a bit easier, but I already have the CANdue, plus I think their shipping to US might be currently suspended, plus the zombieverter has a lot more capability (and price) than what I need. I am not sure if the CANDue can support Chademo protocol by itself or if I will need to get one of the separate boards that others have used in conjunction with Arduino Due to get Chademo working. The CANDue uses the ESP32 chip like the product you linked. I am hoping to get data from the BMS, LDU, and possibly shunt and/or charger displayed on a tablet, via the CANDue. Right now I'm trying to follow some of the instructions on the Wiki regarding programming IVT-S Shunt with arduino Due, but not sure if the exact same steps apply for the CANDue

You will have to code it all up yourself. Have the CANDue process the CAN data then push it out to the tablet somehow.

You will need to manage all various vehicle states and control the onboard charger somehow.

retrEVnoc wrote: ↑Mon Oct 06, 2025 1:43 am plus I think their shipping to US might be currently suspended

Incorrect, EVbmw (Damien) still ships to USA https://www.evbmw.com/index.php/evbmw-w ... vcu-boards

tom91 wrote: ↑Mon Oct 06, 2025 9:22 am You will have to code it all up yourself. Have the CANDue process the CAN data then push it out to the tablet somehow.

Exactly, the big benefit of the Zombie over the CANDue is that the code is already done, with the possible exception of the specifics of your charger.

retrEVnoc wrote: ↑Mon Oct 06, 2025 1:43 am I am not sure if the CANDue can support Chademo protocol by itself or if I will need to get one of the separate boards that others have used in conjunction with Arduino Due to get Chademo working.

CHAdeMO communication is all CAN, so you could make it work with CANDue, but again, you're going to have to find and piece together the code for that. I'm also not sure how many different things you can get the CANDue to handle. That'd be some more advanced coding than I'm comfortable with, but if you have experience there, then maybe its a good option.

P.S.Mangelsdorf wrote: ↑Mon Oct 06, 2025 11:17 am CHAdeMO communication is all CAN, so you could make it work with CANDue, but again, you're going to have to find and piece together the code for that. I'm also not sure how many different things you can get the CANDue to handle. That'd be some more advanced coding than I'm comfortable with, but if you have experience there, then maybe its a good option.

No I am not a coder but I found someone who has been helping me with the software and electronics. Manglesdorf you may have been right about overwhelming the CANDue but we'll see.

Right now the truck can stop and go with CANbus up and running and has rudimentary web UI on a tablet. But the charging and general VCU functions from the CANdue are still kinda buggy, as if my now de-ICED vehicle runs and drives but with an empty tank and no way to fill it!