openinverter forum

I'd like to begin a thread here to document my project, a 2001 Vahxuall VX220, which I hope to modify with a Tesla Model S Rear Small Drive Unit. I've been rambling about this project on the DiyElectricCar forum, but I wanted to record a more concise version here.

I have sourced the following parts:

• Tesla Small Drive Unit with driveshafts and appropriate industrial oil
• 18 x LG 16S battery modules
• Ovartech 6.6kW charger + 1.5kW DC-DC converter
• ISA shunt CAN current sensor / coulomb counter
• 150A and 250A HV relays (came with OEM battery pack)
• 175A, 225A, and 40A HV fuses (came with OEM battery pack)

In addition, I am in the final stages (I hope) of developing two components myself:

• BMS supporting 3 x LG module strings with CAN, documented elsewhere on this forum
• Charge controller to manage EVSE, on-board charger, and any associated systems

So far, the majority of work has been designing electronics and software, but I have now secured workshop space and and moved the car into its temporary home, so I'm committed and it's time to get my hands oily. I have an offer of assistance with mechanical engineering and fabrication where needed, as I don't want to take any risks with my own inexperience in that area, but hope to learn this as I go.

During the coming week I will be removing the clamshell and engine from the car, and hopefully the next step will be to measure up and begin layout planning.

Car looks a good candidate, some nicely chosen components.

Look forward to following along.

Today I was able to remove the engine from the VX220 and offer up the Tesla SDU! Looks very promising so far. Still lots of disassembly and measuring to do before I can commit to a battery pack layout though. One key point is that is is almost essential that the SDU run in reverse, so I will need a solution for oil pumping.

Version 3 my BMS master and my charge controller boards also arrived today, so I will be testing these and hopefully finishing the software in the next few days

This looks awesome! Great project.

How are you progressing?

EV_Builder wrote: ↑Sat Apr 16, 2022 10:03 am How are you progressing?

Things are going well (if a little slowly) thanks! The following is complete:

* Modified SDU to run in reverse
* Mounted SDU in car
* Designed and fabricated battery box - final assembly in progress...
* Bought all necessary electronics and connectors
* Modified cabin heater with high voltage PTC element
* Modified OEM radiator with 16mm pipe connectors
* Removed unnecessary components - clutch, gearstick

There is still lots to do though:

* Finish battery box assembly
* All plumbing
* All wiring
* Adapt / join drive axles
* Mount new direction / gear selector
* Integrate gauge cluster
* Install battery charger and charge port

There is a full rambling log at https://www.diyelectriccar.com/threads/ ... du.205616/

Cool I'm puzzling myself with the batteries at the moment.

Nice going Charlie, soon to be chasing my Smart

The battery box has really dragged on! Almost done now though. Just got to install the batteries themselves, and add some lifting points so it can be hoisted into the car.

Very neat work

Very nice... Stop teasing us we ev porn

Nice how much watts are your battery pack looking for batteries for my 1991 CE Mercedes Conversion with rear SDU have a tight fit had to relocate inverter in the trunk. have no problem
with battery space. This Mercedes came with the M401 cast iron engine over 1000 lbs.
Keep up the good work.

See my 1991 Mercedes 300CE-EV

Very nice work, I notice your running the pre charge on the negative side is there a reason for this. I’ve always done pre charge across the positive contactor, I suppose It doesn’t matter really

Ev8 wrote: ↑Sun May 01, 2022 7:19 am Very nice work, I notice your running the pre charge on the negative side is there a reason for this. I’ve always done pre charge across the positive contactor, I suppose It doesn’t matter really

The only reason it's on the negative side was to balance the space. I put the fuses on the positive side which took up a lot of room, so I put the current sensor and precharge on the negative side. All of these things will work equally well on either side.

qmedia2651 wrote: ↑Sun May 01, 2022 3:51 am Nice how much watts are your battery pack

My pack is 20kWh usable, not particularly impressive, but hopefully the light weight of the car will allow something approaching 100 miles of range from that.

100 mile range depending on how much 'fun' you are having

Peter wrote: ↑Sun May 01, 2022 10:03 am 100 mile range depending on how much 'fun' you are having

Which is the same in an ICE car...

Very nice, do you have partnumbers for the heater socket?

EV_Builder wrote: ↑Sun May 01, 2022 11:36 am Very nice, do you have partnumbers for the heater socket?

It's an Amphenol ePower-Lite. They're available in a variety of pin counts and wire sizes. Check the datasheet here: https://www.mouser.co.uk/datasheet/2/18 ... 261256.pdf

For my heater, I am using ELR2A02 and ELP2A02 which is the 2-pin version for 4mm² wire.

Now that I've finished the design of the battery box and sent it off for powder coating, I've been able to get started on some of the more fun parts of the build. So far this week I've installed the charger and charge port.

Just wanted to do a small post about my plans for low voltage cabling. Luckily I am able to use the huge majority of the OEM wiring, just got to add new wiring for CAN, HV relays, gear selector, and EVSE.
One cool feature here is I believe I can use the start button on the dash as both a start button *and* a cruise control button over CAN.

Openinverter appears to stay in pre-charge mode indefinitely in the period before start is engaged. Are you planning an interlock to prevent pulling current over the pre-charge resistor from the DC-DC/Charger before start is pressed?

cloudy wrote: ↑Sun May 29, 2022 8:55 pm Openinverter appears to stay in pre-charge mode indefinitely in the period before start is engaged. Are you planning an interlock to prevent pulling current over the pre-charge resistor from the DC-DC/Charger before start is pressed?

My DC/DC converter is not behind my inverter contactors, so this isn't a problem.

Everything is now wired up and my small drive unit is spinning! I need to get the driveshafts finished and the braked re-installed and then it might be ready for a test drive!