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Discussion Starter #1
Hi folks,

I'm Matt, from France...
Here conversions are not allowed yet, but was governmently announced for the end of this year and now planning is said to be February 2020.

I've been thinking of converting an old beauty for a while so i'm now engaging first gear in that project in getting good advices. So first of all i registered here and read some very interesting threads and went though the Wiki as well. Thanks a lot for all the shared informations!

I'm a car guy, owning a Lotus M100 and an Innocenti Mini 1001. None of these are gonna be converted, as they are working pretty well. But my daily 2007 Saab will probably not pass the technical review next year, so i'm considering converting an old spider or sedan instead of putting too much money in it.

The idea is either a 5-seats sedan like a Triumph Dolomite or a Saab 99, or even an older MG 1100 or 1300. The other possibility is just go for a 2-seater for my daily commute, such as a Triumph Spitfire. More recent cars such as an MG F or a Mazda Miata could be nice as well, could even be cheaper to find and buy!

After that, general specs are:
- at least 150km effective range (so taking into account 80% DoD, 80% battery aging, 80% winter effect...)
- at least same performances than the original engine. Not either looking for a true sport car.
- i don't want to sell either the Inno nor the Lotus, so i have a main target of keeping the project "cheap" (well, i want to keep my wife as well !).

Concerning budget, the notion i got from surfing around shops like EV-West or EVTV.me, i would say that :
- 3x Tesla Model S modules (~4500$)
- engine 1000$
- controller 1000$
- all the rest (harnesses, adapter plate and so on), hopefully not much than another 1000$
So that's already a 7500$ envelop, without even buying a donor car.

I'm at the very beginning of all that, so any advice on how to handle and arrange all that is welcome! Not started the calculations yet on electric power/energy needed for this conversion. I would first like to asses how much energy and money i have to put on the table and what are the key design drivers before starting anything and having to regret it... And anyway, i will wait for conversion to be road legal in France before doing anything!

Thanks a lot for this mine of informations, looking forward to reading your posts !

Matthieu
 

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Hello!

Your specifications are very feasible - though you may want to rethink your battery selection...

Tesla Model S modules have a nominal voltage of around 22V. This unfortunately means to drive the majority of cost effective motor/controller combinations to reach your performance bracket you will need a lot more than 3. This makes them a really expensive way to form up the battery for your project. To get good performance from a lower voltage battery will require a much higher amperage controller, thicker cables, much more agressive cooling etc.

Perhaps look into other sources of batteries - the most performance/capacity per euro is likely to be found from OEM cells from scrapped/crashed production EVs.

For example; In the UK, a Nissan Leaf battery pack in good health can be found for around £3000-3500 on Ebay or from scrapyards, which gives you a 24kWh battery with a voltage of 360V. In my project (an MG TF) I will be breaking down one of these and using most of the cells (as many as can fit in the donor car. To get equivalent capacity with Tesla modules, I'd need to spend ~£5000 on modules and even then the pack voltage would only be around 88V, severely limiting my options for motors and controllers.

For the lowest cost of conversion, salvaged/used parts are going to be better than new by a long margin.

I wish you all the best for your project, and hope that the french lawmakers don't delay any longer to allow conversions!

Nick
 

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Discussion Starter #3
Hello Nick,

Thanks for your answer. I did not realize this so i definitely have to look better into figures.
I did not think at first about other electric cars. Here we have the Zoe (Renault) that could be a could opportunity and somehow easier to find. I'll check this. It's probably the same powertrain than the Leaf actually.

Would you have some links to share on where to find salvaged/used parts or could eBay really give a good overview of price and panel of choice?

Thanks!
 

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Ebay's not bad - but if you've got local scrapyards they might be worth a phonecall.

The Zoe powertrain is totally different to the Leaf, but in principle - it's still the same idea. You might also want to look into higher voltage modules that some EV conversion parts suppliers sometimes stock - There are good 16s modules from LG Chem that sometimes crop up and have been used before in lots of conversions.

If you're sourcing parts from a production EV, you may also want to consider using other drivetrain parts too. The motors/inverters from production EVs are very capable, and with the right additional electronics, you may be able to use more than just the battery... Let's say you bought a crashed EV in entirety at auction, you might be able to source almost all the parts you need (Battery, motor, inverter, charger transmission etc.)
 

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Discussion Starter #5 (Edited)
OK. Probably my first task is to read and read and read again about other conversions here and there. I realize i don't really know what is available new/used and OEM/"aftermarket".

My guess about the legalisation to come in France is that they are going to separate the "car" homologation from the "powertrain" homologation. So i'll definitely keep the original drivetrain of the car, "from gearbox to the wheels", and only change the powertrain. That's to say engine/motor, tank/battery, controllers etc...

Additional question as a criteria to choose between production EV and part supplier. Is the following rough scheme correct?
- i guess the production EV system should be somehow plug-and-play on any car (implementation in the converted car being the issue, without touching anything in the original system). It probably costs more than buying at parts supplier. And system is optimized for the original car but not for the converted car. Spare parts will be easier to find in 5 or 10 years.
- on the other hand, building my own system from parts supplier may be cheaper, more optimized towards my specs and adapted to the converted car, but it is more tricky to have it working properly. Maintenance stop or obsolescence will show up earlier, but alternatives may arise and allow system update/upgrade.
Correct?

Thanks!
 

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- i guess the production EV system should be somehow plug-and-play on any car (implementation in the converted car being the issue, without touching anything in the original system). It probably costs more than buying at parts supplier. And system is optimized for the original car but not for the converted car. Spare parts will be easier to find in 5 or 10 years.
- on the other hand, building my own system from parts supplier may be cheaper, more optimized towards my specs and adapted to the converted car, but it is more tricky to have it working properly. Maintenance stop or obsolescence will show up earlier, but alternatives may arise and allow system update/upgrade.
I would wait for some more experienced people to weigh in here, but I think you might have it slightly backwards.

Implementing the full system from a production EV into a conversion may be tricker than you expect, as everything in modern cars is connected to their CAN network - i.e. if you take a part from a production EV out of it and try and use it in isolation, it might not work at all without decoding and emulating the CAN messages flying back and forth in the original production EV.

Parts designed for EV conversions are largely independent, so it might seem more plug and play once you've studied the datasheets for those parts. For example, if you purchase a CAN enabled BMS, you can likely configure it to work independently without CAN if you wanted. Best thing to do is more research as you said :) It might be worth searching EVAlbum for conversions in similar cars to your Donor to give you an idea of layout and packaging within your size requirements etc.
 
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