VW T3 EV Conversion Kit

Tell us about the project you do with the open inverter
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willywonka
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VW T3 EV Conversion Kit

Post by willywonka »

Hi folks

I would like to introduce our project to you. This first post is quite lengthy, my apologies for that. However, most of the background info has quite substantial influence on the decision making, as we are operating in the EV conversion hell Switzerland, where all innovative ideas instantly get squashed by rules and regulations! :lol:
For those of you not interested in the background info, I would suggest to jump directly to the requirements and to have a look at the first big design questions at the bottom of the post.

Of course we are more than grateful for any comments, feedback, advice... Thanks!

Project goals
We would like to create a “EV conversion kit” for VW T3 (“Vanagon”) busses, consisting mostly of readily available second life parts. This kit should primarily comply with the Swiss regulations for conversions, which are – mildly said – probably among the toughest worldwide. We would like to use as many second life parts as possible to make the kit affordable as well as to hopefully have a bit of a better standing when it comes to the certification as the parts have already been certified in one or the other form in other vehicles on Swiss roads.

Motivation
We are two VW bus addicts. And while we very much enjoyed the typical sound of our busses, there are more and more bus owners who would like to combine their love for their old and stylish busses with their interest in today's state-of-the-art clean and silent automobile technology. When I started a quick spread sheet on the Swiss VW bus forum, within a few days there were already more than a dozen entries for people who want to convert their busses.

However, the Swiss government officials have the unfortunate tendency to over-regulate – and EV conversions make no exception. The key regulation items to adhere to are:
  1. If you increase power by more than 20% of the original power the car has (as printed in the vehicle documents), you have to go through a very lengthy and expensive inspection process.
  2. The new motor must be attached to the original mounting points in the frame.
  3. Since the beginning of the year (2020), EV conversions have to undergo very pricy electromagnetic compatibility (EMC) test.
At least for the EMC test it looks as if this could be reduced to some degree for following conversions if the first conversion passed the tests successful and the others are built with the same kit.

But by developing a kit we not only hope to reduce the extremely high cost for the certification, we also hope to be able to reduce the effort and money needed per conversion by producing a series of adaptor plates for instance and only have to work out the inverter control once. Finally, we also hope to keep costs low by using second life parts. If you try to do a conversion with a kit from eveurop.eu for instance that would match the requirements below, you would end up at €30k for only the kit. For that money, it would probably be smarter to order a Sono Sion or simply keep the ICE and do a carbon offset for the gas you burn.

Requirements

Drivetrain
  • max. 80kW (continuous)
    The limit to comply with the max. 20% power increase rule would be 77kW
  • min. 200km range
    In warm weather. The T3 will be using about 25kWh/100km according to our calculations. So a 60kWh battery should just about give us the necessary useful kWh.
  • Fast charging
    1h to 80% would be nice.
Body
  • Fit for both 2WD and 4WD T3 busses
    This means that we will most likely have to keep the original transmission in the bus and attach the electric motor to the bell housing with an adapter plate. It would be nice to “lighten” the transmission a bit though by getting rid of everything not needed anymore.
  • No hacks to the body/frame
    As mentioned above, the engine needs to be mounted to the original mounting points in order to comply with the DMV regulations. Copping away parts of the body to fit the engine is out of the question.
Nice to have
  • Electric power steering
    It would be nice to fit an electric power steering from a Toyota Camry or similar that would support comma.ai openpilot. I mean, while we're at it, we might as well... don't you think?
  • Replacement of power brakes system?
    The T3 has a large vacuum power brake system. Maybe there is a more efficient way than to run an electric vacuum pump?
Budget
Due to the change in the Swiss regulations for EV conversions we pretty much gave up on the project late last year. With a parts tab running north of €30k and certification costs exceeding €10k the project is just way out of our league – and frankly did not make any sense even for the most enthusiastic mind. Then I tripped over Damien’s videos and all the hacks on openiverter.org. This gave me some new inspiration and I started looking for more than just Tesla batteries and new inverters and motors from the known distributors. By using the parts from salvaged EVs and (for now) build two identical conversions we're hoping to be able to split the EMC certification cost almost by two, allowing us to hopefully realize the goals with a budget of max. €13k/car (only ev drivetrain and certification). If this works out, we would ultimately like to be able to get in the neighbourhood of €10k for a kit including certification (of course excluding any labor).

Risks
As you might have noticed above, the word “hope” is used sever times. There is a whole truckload of unknowns in this project at this time. These are the biggest risks we see at the moment:
  • EMC certification
    If we cannot get some form of “serial certification” for the kit with maybe a minimal individual test of each conversion, the project is not feasible. There are efforts going on to make the certification process a bit more reasonable, but these processes are very lengthy.
  • DMV certification
    Besides the EMC certification each vehicle in Switzerland also has to undergo a strict test by the DMV. The biggest problem there is to get the modifications accepted (increase of power, changes to heating, steering, breaking system…).
  • Good second life parts
    The parts need to match the requirements, need to be affordable and of a good quality. They are very hard to get in Switzerland, so importing them will be another obstacle to overcome.
  • Missing know-how
    We do cover quite a broad know-how but are no electrical engineers. Therefore we would rely heavily on the help either from communities like the openinverter.org forum or from paid professionals.
  • Missing time
    As always, you never have enough time for hobby projects.
  • Finances
    At this time with all the unknowns it is very hard to say if our budget is sufficient for the project. And we are not in the position where we can easily expand the budget.
Design questions
So, with all the uncertainties, it is time to list the biggest questions we need to answer before we can dive into the project:
  • Which motor, which inverter, which battery pack, which charger?
    With the givien limitation to 77kW (continuous) power, the BMW i3 looks like the best option for the motor. We also like the i3 battery back with its good energy density and thermal control. Therefore it seems like it would be our best bet to simply look for totaled BMW i3’s and salvage the complete drivetrain from them. However appart from 2 videos from Damian there is next to no information available on people having successfully used these parts in conversions.
    On the other hand, every secret of the Nissan Leaf drivetrain seems to have been uncovered. We also really like the inverter/charger combination on later Leaf models. Unfortunately the motor slighly exceeds the power limits.
    Mixing parts or trying to stick to one manufacturer
    I have the (completely unfounded) hope that the certification process might be a tad easier if the whole drivetrain from one manufacturer & model is used than mixing parts from multiple manufacturers.
  • Original boards vs. replacement boards
    As a software guy, I liked what I read about being able to control the Nissan Leaf inverter with the original board over the CAN bus. This looks like the simplest solution to me. But then again, I can see the advantages of having a replacement board giving you full control, and admire the work of Johannes, Damien, Paul and others.
As mentioned at the top: Happy to get your feedback, thoughts etc. on the project.

Cheers!
Will
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Re: VW T3 EV Conversion Kit

Post by RetroZero »

Hello, Will. Where are you based? I am doing a similar set up in France (close to Geneva). Very similar questions being asked as regulations about the same. I would say, look at Tesla Small Drive Unit as drive option to original gearbox. From memory, Tesla is biggest seller in Switzerland = largest amount of parts available. That is where I am starting from....
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Re: VW T3 EV Conversion Kit

Post by willywonka »

Good morning RetroZero

Thanks for your input. I never had a closer look at Tesla parts, because
  • I was under the (false?) impression that the drive units would be much to powerful.
  • Usually, when it says "Tesla" on a part, it's about double in the price in relation to comparable parts from other manufacturers.
But thanks to you I did google for the Tesla small drive unit now... and I'm not sure if I fully understand the numbers. As far as I can tell, there is a SDU for the front and one for the rear axle. For the certification in Switzerland, the continuous power is used. But as a newbie in this field, I'm having a hard time putting the numbers in perspective. 30kW continuous to 220kW peak seems like an awfully big range, compared to the 75kW - 125kW range of the BMW i3. If the 35kW continuous power for the Tesla SDU are true and officially marked on the motors, I could even put two of them in a VW T3... which would be insane as these engines would probably rip the T3 body apart.

You see: I'm very much trying to get a grasp on the topic... ;-)

Will

BTW: If the numbers above are correct, it would be something valuable for the https://openinverter.org/wiki/Tesla page.
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Re: VW T3 EV Conversion Kit

Post by arber333 »

Ya, the peak power is due to motor being able to give short burst of huge power. Not good idea to continuously use that as motor can build up dT much faster than it can be cooled down.
You can increase rated power with clever design of cooling system or by using additional dQ system like AC.
On one side you input liquid to the exchanger which is cooled by refrigerant BELOW ambient temperature. Then when this coolant arrives to motor you have the dT difference which can give you additional continuous power for a time. Lot of racers use this kind of system.
In our Ampera hybrid there is AC exchanger installed to cool down battery coolant quickly. So even manufacturers thought about this...
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Re: VW T3 EV Conversion Kit

Post by joromy »

willywonka wrote: Sun May 17, 2020 6:42 pm max. 80kW (continuous)
The limit to comply with the max. 20% power increase rule would be 77kW
The actual power rating of a motor, is not relevant.
I use a Siemens motor, and can set about double the power output.

If you have a openinverter board you can set whatever power level you want.
So if you must lower the power, the motor will just have a better life. :)

But what do the inspection guys look for, the motor plate kW, or a document from dyno test?
Thomas A. Edison “I have not failed. I've just found 10,000 ways that won't work"
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Re: VW T3 EV Conversion Kit

Post by arber333 »

joromy wrote: Mon May 18, 2020 8:23 am But what do the inspection guys look for, the motor plate kW, or a document from dyno test?
In Slovenia you need to have a motor plate that states LESS power than the maximum power of engine in original type design. So if you wanted to put tesla LDU into VW beetle they wouldnt let you.
Which is honestly not so wrong, since a lot of factors depend of chassis strength. By introducing too torquey motor you are out of the known design. Probably they would deal with that on one to one basis similar to turbocharger motor installation etc...
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Re: VW T3 EV Conversion Kit

Post by Kevin Sharpe »

willywonka wrote: Sun May 17, 2020 6:42 pm we are operating in the EV conversion hell Switzerland
You will probably need to get your solution CE tested and this could have a big impact on your choices if you're doing this commercially.

If using off the shelf commercial parts then try to select vendors who are going to be around in 5 years time because you are going to spend a lot of money on testing. Obviously, you could use up cycled OEM parts but some, like Tesla Model S/X motors for example, are unlikely to be around in the same form which would require retesting at some point. One possible way forward is to select parts like the Prius Inverter that you can buy as spare parts for the next 10 years.

In The Netherlands we have a tough approvals regime (here) that forces us to only use the three kits of parts that we've tested for our commercial conversions. We hope eventually to use more open source parts but the costs of approvals and lack of long term availability have made that impossible to date.
This is a personal post and I disclaim all responsibility for any loss or damage which any person may suffer from reliance on the information and material in this post or any opinion, conclusion or recommendation in the information and material.
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Re: VW T3 EV Conversion Kit

Post by tmotion »

Great idea. Some comments from my side, since I own a T3 and am converting it to an EV. I like the starting points and requirements but I think they do not match with the price of 13K. The T3 is a brick on wheels with 0 aerodynamic properties. Achieving a 200KM range is difficult with limited batteries. The 120Ah I3 pack has 42kWh. With 10% reserve you'll have 38kWh. The i3 manages 200km just yet on the highway and it has a Cw of 0.3 instead of 0.52 for the T3, Its frontal area is almost half and the weight as well.

When I do my calcs you'll need at least 65kWh when driving 100kmh average for 200km range, or 50 kWh when doing average of 80kmh. Batteries are the most expensive part of the kit in the end. As for their location. The T3 has a nice space underneath between the two main beams: 732x1730mm. In my opinion this is the safest spot for a battery pack. It is collision proof, has sufficient mountin points and is nice and low. 10 tesla modules fit in there and so do 8 i3 modules or 20 ipace modules. Keep in mind in a 4wd a driveshaft is there. Using the sides for batteries would not be my preference from a safety perspective, one collision from the side and your batterypack is heavily damaged with possible worse effects as well.
Make sure that you get your voltage close to 400V if you have to do nice fastcharging, at 250V for example fast charging will be disappointed if it even works.

The tesla SDU is a perfect fit for the T3. I'll use one myself as well. Their price is dropping quite fast. Last year average was 3500€, now you can find them for 2000€

As for EMC testing, latest indiction I got from Dutch authorities was 8000€ when combining EMC approved parts myself. When using parts from only 1 vehicle producer which are already used in a type approved vehicle this will be significantly cheaper. I was planning on using ipace cells, but am switching back to tesla modules for this reason. 10 underneath and 4 in the old enginebay. This will give me 74kWh, 350V and 225-300km range.

Anyway I'm planning to share all my engineering efforts and approval, so if you're patient you can use my efforts. But it will not be a 13K€ kit.
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Re: VW T3 EV Conversion Kit

Post by willywonka »

Thanks for all the helpful feedback, guys! Amazing!
joromy wrote: Mon May 18, 2020 8:23 am The actual power rating of a motor, is not relevant. I use a Siemens motor, and can set about double the power output. If you have a openinverter board you can set whatever power level you want.
That's exactly the reason why the guys at the inspection center are looking at the official plate on the motor. So if the plate on the Tesla SDU actually says "35kW continuous power" I will be fine. :-)
tmotion wrote: Mon May 18, 2020 8:01 pm The T3 has a nice space underneath between the two main beams: 732x1730mm.
Nope. Our busses are Syncros. So unless we put two (2!) Tesla SDU in them, that space is going to be occupied by the drive shaft. So I am hoping to be able to build good containers to put the pack to the left and the right of the main beams as well as in the former gas tank area and the engine bay.
Does anyone have CAD-drawings (or exact measurements) of the BMW i3 battery modules?

As for the range and budget: I guess we will have to do a compromise there and start with a lower range. The 120Ah BMW battery packs are not yet that readily available....

That being said: I'm very open to use the Tesla SDU. That would also allow us to share resources and maybe speed up the process a bit. But I have not found anything below €3000 yet. For that kind of money I'm getting a complete i3 drivetrain... almost. ;-)

Cheers,
Will
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Re: VW T3 EV Conversion Kit

Post by Kevin Sharpe »

tmotion wrote: Mon May 18, 2020 8:01 pm As for EMC testing, latest indiction I got from Dutch authorities was 8000€ when combining EMC approved parts myself. When using parts from only 1 vehicle producer which are already used in a type approved vehicle this will be significantly cheaper.
AFAIK the 'cheaper' route only works if you use the parts as originally packaged. Removing modules from the Tesla pack or fitting a new controller board in a motor will invalidate the OEM certification and require retesting.

I've also been told that you can only use the OEM's certification in a submission if they give you permission. I'll try to get this confirmed from the folks in Amsterdam.
This is a personal post and I disclaim all responsibility for any loss or damage which any person may suffer from reliance on the information and material in this post or any opinion, conclusion or recommendation in the information and material.
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Re: VW T3 EV Conversion Kit

Post by willywonka »

So it looks like I will go get the donor parts from a totalled BMW i3 in about two weeks! As mentioned, my goal is to use as much original parts in original combination as possible to hopefully reduce the problems with getting it approved at least a bit. The question at the moment is: What parts do I need to salvage in order to get a "running" system? Of course the motor, inverter, battery, charger, accelerator and break pedal. But then there are probably two dozen of controllers and sensors that also should be coming along and don't even mention the wiring loom... and I only have a day to get everything I need out of the car! :o

I don't assume anyone of you has done this before and could give me some advice, right? :)
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Re: VW T3 EV Conversion Kit

Post by willywonka »

BTW: I guess it would be nice to post a pic of the T3 which should be electrified first:
IMG_3255.jpeg
The whole "rustauration" thread can be checked out on the Swiss VW bus forum:
https://vwbusforum.ch/t/monster-ii-besc ... agen/13585
But beware: The thread is long, in German and definitely not rated PG-13 as it contains many many pictures of pure and utter horror (rust everywhere!). :shock:
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Re: VW T3 EV Conversion Kit

Post by Bentto »

Kevin Sharpe wrote: Mon May 18, 2020 9:13 pm
tmotion wrote: Mon May 18, 2020 8:01 pm As for EMC testing, latest indiction I got from Dutch authorities was 8000€ when combining EMC approved parts myself. When using parts from only 1 vehicle producer which are already used in a type approved vehicle this will be significantly cheaper.
AFAIK the 'cheaper' route only works if you use the parts as originally packaged. Removing modules from the Tesla pack or fitting a new controller board in a motor will invalidate the OEM certification and require retesting.

I've also been told that you can only use the OEM's certification in a submission if they give you permission. I'll try to get this confirmed from the folks in Amsterdam.
Very interested in this info about using OEM's certification. Very frustrating that the Netherlands decided to make things complicated, now that we are introducing EU legislation everywhere I think this should be the same for all countries in the EU.
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Re: VW T3 EV Conversion Kit

Post by willywonka »

Despite the fact that
a) the BMW i3 motor / inverter seems to be pretty much uncharted territory
b) and more importantly me not having any clue about what I'm doing here
I did go ahead and picked up all the parts I could possible need last weekend from a donor car.

I did check the voltage of the cells: 3.85V. IIRC this is a tad high for storage, right? I don't think that there will be much going on with it in the next 6 months or so. So can I leave it at this?

Cheers!
Attachments
After 6 hours of dismantling
After 6 hours of dismantling
Battery and engine loaded ready to head home
Battery and engine loaded ready to head home
While the body (carbon) is super light, the wiring loom weighs a ton!
While the body (carbon) is super light, the wiring loom weighs a ton!
Not much left in there!
Not much left in there!
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Re: VW T3 EV Conversion Kit

Post by Scrappyjoe »

Great to see this willywonka! I’ve also got a syncro that I plan to convert in 2025, so I’ll watch this with interest.
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Re: VW T3 EV Conversion Kit

Post by ArKamin »

Hallo allerseits,
Seit kurzem habe ich auch einen T3 LLE den ich gerne umbauen würde.
Wie es scheint, ist seit langem nichts neues hier gepostet.
Ist der Umbau gelungen, gibt es neue Infos?
VG
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Re: VW T3 EV Conversion Kit

Post by Scrappyjoe »

Willywonka, have you started looking at how the i3 motor will mount in the back of the syncro? WIll you keep the diff? Or will you mount the motor directly to the existing transaxle via a coupler plate?

The rule of thumb here in South Africa is that the max torque you can put through a stock syncro gearbox is about 185Nm. Looks like the i3 motor puts out between 250 and 280 Nm depending on the model, so if you’re keeping the transaxle maybe think about limiting the motor output to those torque specs. For the 2wd variant the most powerful engine we had here was the 2.6i which topped out at 200Nm and it had a few additional design features like oiling plates and a braced transmission case.
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Re: VW T3 EV Conversion Kit

Post by Scrappyjoe »

My understanding from watching too many YouTube videos is that EV converted buses tent to spend most of their lives in 3rd gear, so maybe getting an upgraded 3rd gear is a good idea (but expensive). The consensus on this forum, as far as I can see, is to drop the clutch as ICE clutches get destroyed quickly with EV motors. One can still shift without a clutch after all, so you retain your G gear for crawling.
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