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!
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:
- 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.
- The new motor must be attached to the original mounting points in the frame.
- Since the beginning of the year (2020), EV conversions have to undergo very pricy electromagnetic compatibility (EMC) test.
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.
- 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.
- 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?
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.
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.
Cheers!
Will
