# Working on a 1989 Classic Mini EV Conversion



## Scanales (Apr 13, 2020)

Hello Everyone,

Starting work on my 1989 Mini. Thinking of keeping the original gearbox and mounting a Hyper9 motor directly on top of it. Using SilentSync sprockets and belt as a drive system. Have something similar to bdrive.ch ´s conversion in mind. But interested in using the Hyper9 9 and some Tesla modules from the get go.


Also considering the EV Europe system: https://eveurope.eu/en/product/ev-hype-kit-low-voltage-max-90-kwatt-180-vdc/

I have no advance knowledge in EV conversions so I want to keep everything as simple as possible for this one.

Interested in getting some feedback from you guys who are the experts. Let me know your thoughts. 

Am I in the right path or is this combo I have in mind a not so good Idea.

Cheers


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## Tomdb (Jan 28, 2013)

Where are you based as this will effect what you can legally do?

I am also looking at a mini at the moment, I can tell you tesla modules mean you have to sacrifice quite alot of space in the car.


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## Scanales (Apr 13, 2020)

Based in Mexico! No real worries about what I can legally do. 

On the battery side, I was thinking on 5 x 5.2kWh modules. It will be a tight fit.

What are your thoughts on batteries?


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## Tremelune (Dec 8, 2009)

What is SilentSync? Driving a Mini transmission with anything other than a Mini motor is...non-trivial. They're also designed to handle less than 100ftlb of torque...An option there would be to use a Honda conversion subframe and transmission (which opens the door for AWD), but it's still tricky to get a belt/gear system working to spin it.

Tesla S modules have good power density, but their length makes them tough to fit. Were you planning on keeping the rear seat? What range are you hoping for?


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## brian_ (Feb 7, 2017)

Scanales said:


> Thinking of keeping the original gearbox and mounting a Hyper9 motor directly on top of it. Using SilentSync sprockets and belt as a drive system...


I understand wanting to keep the original powertrain mounting and axles, but the Mini engine and transmission setup is very undesirable for conversion to an electric motor. The consensus seems to agree with Tremelune: use an aftermarket (or modified stock) subframe to mount a more suitable transaxle, or to use the entire drive unit (motor with transaxle) salvaged from a typical production EV.



Scanales said:


> Also considering the EV Europe system: https://eveurope.eu/en/product/ev-hype-kit-low-voltage-max-90-kwatt-180-vdc/


The electronics package mounted directly on top of the motor is a tidy setup for many vehicles, emulating the shape of a typical engine which is being replaced, but it looks very tall to put in a Mini, especially stacked on top of the transmission. I would check dimensions carefully.


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## Brendon_m (Jun 16, 2018)

I have converted a 77 moke and successfully kept the original transmission. It works but it was a pain to do and the gearbox is noisy and I'm always worried I'm going to destroy the 40 year old Leyland gearbox /driveshafts with the new power. 
If I was to do it again I would look to drop in an imiev running gear or maybe fit a rwd cars diff to the front and belt/chain drive it with the motor sitting on top of the diff.


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## pickmeup (May 8, 2018)

Brendon_m said:


> I have converted a 77 moke and successfully kept the original transmission. It works but it was a pain to do and the gearbox is noisy and I'm always worried I'm going to destroy the 40 year old Leyland gearbox /driveshafts with the new power.
> If I was to do it again I would look to drop in an imiev running gear or maybe fit a rwd cars diff to the front and belt/chain drive it with the motor sitting on top of the diff.



do you have any links to the build and how you adapted the box to work? Are you using the original transfer gears or a chain/belt drive to the input shaft?


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## Brendon_m (Jun 16, 2018)

Build thread is here
https://forums.aeva.asn.au/viewtopic.php?f=33&t=5608

Look at page 3 for the info on my coupler. 

I used the original drop gears but my method probably won't help you* as I squeezed the motor in where the clutch used to live on the end of the old ICE and it only just fit in there by a few millimetres and the moke (apparently) has more room in the engine bay compared to a mini

*Edit - just noticed the person asking for the link wasn't the OP, so maybe it is relevant and may help.


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## Tremelune (Dec 8, 2009)

In short: It involved a _lathe_.


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## Scanales (Apr 13, 2020)

Thank you all for the feedback! MAIN reason for that setup was to keep it as simple as possible.

However starting too look at different options. Keeping the subframe may be easier than a complete new setup.


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## Scanales (Apr 13, 2020)

Hello everyone,

Stumbled with this option online:

https://swind.life/products/hpd-2/

Size seems manageable, price wise seems similar to what I had in mind. Will the Shafts be an issue? Should I go for the limited slip diff? Using this system with other components non SWINDON could be challenging?

Regards


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## Tremelune (Dec 8, 2009)

Nice little lump, but unless they'll also sell you a Mini subframe that fits it, I'm not sure I see the point over a Leaf (unless they're hard to find?)...

£6,400 is pricey...Even £2,000 is...


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## Scanales (Apr 13, 2020)

4,980 GBP in the config I need it, it can go up to 6,400 GBP.

Already tried the leaf alternative. It is really hard and expensive to get one of those in Mexico as there is just few of them on the roads.

With the diff ratio of 6.332, should be able to reach around 90 mph top speed.

Weight and dimensions seem ok... 

Another option to contemplate I guess


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## Tremelune (Dec 8, 2009)

See if you can get a subframe and axles, too...They build these things (but charge six digits):

https://swind.life/products/e-classic/


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## Scanales (Apr 13, 2020)

This is a CAD dwg just for size reference. I just got confirmation they will be selling shafts and a subframe.

I’m really leaning into this solution.


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## brian_ (Feb 7, 2017)

Scanales said:


> Stumbled with this option online:
> 
> https://swind.life/products/hpd-2/
> 
> Size seems manageable, price wise seems similar to what I had in mind. Will the Shafts be an issue? Should I go for the limited slip diff? Using this system with other components non SWINDON could be challenging?


That looks like a nice package. Not much different from typical salvaged EV drive units in design and performance, but potentially easier to work with... but that's why they need to describe inverter options and support use of any aftermarket inverter/controller, as well as to document the axle outputs and support the use of various inner CV joints. It's a lot of money compared to a salvaged unit if you are stuck with their controller and it isn't easy to use, and if you are required to custom-build axles.

It's unlikely that Swindon builds any of this - they have presumably just contracted with a motor supplier and a gearbox supplier (and an inverter supplier), but that is useful to the DIY builder if it makes it possible to buy one of each at a reasonable price, since most of these products are only available in production quantities.

I haven't checked the dimensions against the Leaf unit, but I assume it's a reasonable size. It also has substantially lower torque but the same power, which means that it doesn't produce the rated 80 kW until about 5600 rpm - twice the motor speed of the Leaf motor, because it has half the rated torque. That's okay for a small car such as the classic Mini, but anyone considering it for another application needs to think about that. It can't run any faster than a Leaf motor, so simply choosing the higher gear reduction ratio is not a solution if you need to achieve highway speeds.



Tremelune said:


> See if you can get a subframe and axles, too...They build these things (but charge six digits):
> 
> https://swind.life/products/e-classic/





Scanales said:


> I just got confirmation they will be selling shafts and a subframe.


There's the problem: they probably have no intention of actually selling any of these, other than as part of a complete conversion. Since they have the parts (to do the conversion), they threw together a marketing brochure for them, in case they might sell a few that way. If you need to use their shafts then they (and their cost) should be considered as part of the package, and the drive unit isn't as useful for other vehicles.


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## brian_ (Feb 7, 2017)

Scanales said:


> This is a CAD dwg just for size reference.
> ...
> I’m really leaning into this solution.


It's interesting how much more robust the final drive of the Swindon-supplied unit appears to be, compared to the original Mini bits. It does look promising.


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## pickmeup (May 8, 2018)

the guys at swindon powertrain are very clever guys, i do think 6400+ VAT is a bit pricey considering you will need to buy all the other relevant items to make it work.
Its a nice compact unit making it ideal for a mini which i have seen in the flesh at the CENEX show in the UK a couple of years back.


But as the cost of there conversion mini starts at 79K i would presume all the parts to do the conversion would be knocking on at least 30-40K?


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## schelle63 (Jan 3, 2018)

Hello all,
may I add some remarks:
I have converted my Mini with a 27kW-powertrain (from a Th!nk as donor car). With these 27kW I can make the front wheels spin at any time I want (sometime I fail to avoid it) from zero to approx. 60km/h. Top speed is 105km/h, because I have limited the max. rpm of the motor (AC, asynchroneous) to 10.000 1/min. Some people tell the motor can do 12.000 1/min, maybe I will try this some day. The car makes a lot of fun!


To me it appears not reasonable to install a 80kW-engine into a 680kg-Mini with a front-wheel-drive. It might make sense if you build a RWD- or AWD-car, or if you want a top speed far beyond 180km/h.
You should also consider that in order to make 80kW, the battery must provide this power; doing that without damage, it must be a big (and a heavy) one. Which might not suit to a Mini.


Sorry if this does disappoint You, it is just my opinion. After all it is up to You how to convert your Mini. I whish you success!
Markus


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## Tremelune (Dec 8, 2009)

schelle63 said:


> I have converted my Mini with a 27kW-powertrain (from a Th!nk as donor car). With these 27kW I can make the front wheels spin at any time I want (sometime I fail to avoid it) from zero to approx. 60km/h.


Nice! Do you have a page or thread with more details? How do you control the motor? Did you keep the Mini gearbox?


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## schelle63 (Jan 3, 2018)

Hi,
I installed the entire drivetrain (motor, reduction gear/diff). During the mechanic installation I learned that Caspar Hille from Norway (he has posted a thread here...) had done the same thing already some years ago! He could give me some highly appreciated hints, fortunately. What a nice project!
Motor/gearbox-assembly fits nearly perfectly into the Mini-Subframe, there is only one area (front, RH) to be cleared. It was much easier than to install a LEAF-drivetrain, as You do.
I could keep the original controller (both motor and controller are from Siemens). With a 486-computer (!), the right software, the Siemens-manual and a OBD-to-RS232-adaptor (all this appeared harder to find than the donor car itself), all parameters can be tuned.
Currently I am converting my second Mini, some information (also little from the first one) can be found here:
https://www.goingelectric.de/forum/viewtopic.php?f=41&t=55942
https://www.mini-forum.de/threads/94412-Mini-mit-Elektroantrieb
Have a great day!
Markus


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## Tremelune (Dec 8, 2009)

Nice! I wish those cars were sold in the States.

Maybe if I get _real_ crazy, I can try and put a Think motor in the front, and put my Leaf motor in the rear with this cage:

https://www.instagram.com/p/CBaVY7kIhl_/


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## brian_ (Feb 7, 2017)

schelle63 said:


> I have converted my Mini with a 27kW-powertrain (from a Th!nk as donor car). With these 27kW I can make the front wheels spin at any time I want (sometime I fail to avoid it) from zero to approx. 60km/h. Top speed is 105km/h, because I have limited the max. rpm of the motor (AC, asynchroneous) to 10.000 1/min. Some people tell the motor can do 12.000 1/min, maybe I will try this some day. The car makes a lot of fun!
> 
> 
> To me it appears not reasonable to install a 80kW-engine into a 680kg-Mini with a front-wheel-drive. It might make sense if you build a RWD- or AWD-car, or if you want a top speed far beyond 180km/h.


Does the Th!nk have, by coincidence, a 27 kWh battery and a 27 kW motor? The specs that I have seen show a 27 kWh battery and a 34 kW motor.
Although 80 kW is more than enough for a Mini, an EV converted Mini will be heavier than the original version, and it's not unreasonable compared to higher-performance modern vehicles.

Many years ago, when Ford put a then-unprecedented 220 horsepower engine in the front-wheel-drive Taurus, discussion broadly concluded that about 200 hp per ton of gross vehicle weight was manageable with front wheel drive. 200 hp is 150 kW, and the converted Mini will weigh about a ton, so with 80 kW it's way short of being unmanageable. It is, of course, both more powerful than an original Mini and more powerful than necessary to be enjoyable.


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## schelle63 (Jan 3, 2018)

Tremelune said:


> Nice! I wish those cars were sold in the States.


Surprisingly, the Th!nk was built in the USA! At that time they belonged to the Ford group. Some years later when the car manufacturers made the EVs disappear, many Th!nks (440 ea?) were saved by bringing them outside (mainly to Europe).
https://en.wikipedia.org/wiki/Who_Killed_the_Electric_Car?


I was also considering a AWD, in fact there is a Audi-TT rear axle in my garage, waiting to be fitted into a Mini some day...


Brian, I do not remember the Th!nk's battery specification. I have the drivetrain from the early A266. The later type was the A306, with more power and various battery technologies. This explains different figures concerning power and capacity.


An electric vehicle does not need to be heavier than a ICE-powered car: my Mini is 660kg, while original specification was 680kg. My battery has nominal 16kWh (90kg) which gives me a range of about 100km. I have a set of battery-cases that give me additional 50% range, when I need it (this happened once in the last 12 months).


Have a nice day!
Markus


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## schelle63 (Jan 3, 2018)

Coming back to the topic of this thread, which is Scanales' request for information:
I highly recommend to skip the Mini's gearbox - it is a heavy monster!
Just had a closer look to that motor-diff-assembly from Swind, a nice composition. It is my impression, however, that the diff.-housing has a great diameter and requires a lot of space, which is missing in the Mini. Would be interesting to see in detail how they install this into the Mini-Subframe. After all, the specifications of their Mini are pretty good. Maybe "pickmeup" made some photograph?


Besides, there is also this company in France:
https://www.ian-motion.com/
and this one in the Netherlands:
http://www.electricmini.nl/


Regards,
Markus


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## pickmeup (May 8, 2018)

i have seen some other information about the swind e motor and they do have to cut into the rear of the subframe and there is some extra brackets required for mounting points.


the only photo ive seen on the internet with the motor in the subframe is this one below.


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## Scanales (Apr 13, 2020)

Thanks for the photo! @Pickmeup That’s the first time I come across the assembly.

I’m in the process of clearing out the engine bay and removing the ICE components. I do really like what they are doing at SWINDON but pretty much still open for other solutions. I think their own experimental mini is a clear example of what can be done with that 80Kw - it could clearly be used for something a bit bigger and heavier....

Being in México, using a donor car for the motor and parts is quite tricky since there’s not many of them in the market. I have also come to the conclusion that if I’m doing this conversion I might as well get rid of the old rusty parts that may limit me or give me trouble in the future (Gearbox). So I’m in between mounting a Hyper9 with a new subframe and a more modern gearbox or using the Swindon tech. 

Pretty much a newbie to EV technical stuff here so I really appreciate all of the info you guys have given me and all of the useful insights I can find in other threads.

I will be updating you with progress and decisions I make.

Cheers


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## Scanales (Apr 13, 2020)

OK, so if I’m going with the Swindon HPD E POWERTRAIN I have a couple of options and I would really appreciate your thoughts on both topics:

1) MCU: 144V Curtis 1239 or RINEHART 400V PM100DX.

Judging from the photo they went with the PM100DX with their own Mini.










2) To include or not a Limited Slip Diff?

Meanwhile I have stripped the mini to its shell, needs some bodywork done and it will then be sent to the paint shop.










Cheers


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## pickmeup (May 8, 2018)

what will you be using the mini for? if you are going to go for track use then an LSD will help. Otherwise its not really required.


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## Scanales (Apr 13, 2020)

I’m aiming for a daily city driver which I can occasionally use to drive to a weekend spot 100 miles away, charge overnight and drive back. 80 mph is the objective top speed. Will be making some changes to the mechanical side to make it a more comfortable daily, need the components to be reliable and provide the speed and performance needed for the short weekend trips. Thought the LSD could help with axle shaft/tire wear and help with traction on the “High speed” highway weekend trips.


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## brian_ (Feb 7, 2017)

pickmeup said:


> what will you be using the mini for? if you are going to go for track use then an LSD will help. Otherwise its not really required.


I agree, basically - if it is not used for aggressive driving (track or not), limited-slip is not necessary. It's not even desirable, since any mechanical LSD inherently applies too much torque to the tire on the inside of a turn and fights the desired turn. This is true even with rear wheel drive, but an LSD is particularly undesirable with front wheel drive, which is one reason that LSDs are much less commonly used in the front.



Scanales said:


> I’m aiming for a daily city driver which I can occasionally use to drive to a weekend spot 100 miles away, charge overnight and drive back. 80 mph is the objective top speed. Will be making some changes to the mechanical side to make it a more comfortable daily, need the components to be reliable and provide the speed and performance needed for the short weekend trips. Thought the LSD could help with axle shaft/tire wear and help with traction on the “High speed” highway weekend trips.


None of that suggests a need for LSD. It certainly won't help with wear of anything, unless your idea of highway driving involves spinning the tires.


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## brian_ (Feb 7, 2017)

Scanales said:


> OK, so if I’m going with the Swindon HPD E POWERTRAIN I have a couple of options and I would really appreciate your thoughts on both topics:
> 
> 1) MCU: 144V Curtis 1239 or RINEHART 400V PM100DX.


With the same motor? It seems unlikely that a motor which is suitable for 400 volts would provide decent performance over a wide speed range with only 144 volts. The torque (and power) curves on the product web page confirm this - I can't think of any vehicle for this which this powertrain would be useful with the 144 volt configuration.

Of course, to get anything like the published 400 volt performance, you need close to that battery voltage.


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## Scanales (Apr 13, 2020)

Thanks @brian_ and @pickmeup for the info. 

It’s the same 80kW motor. I will be going for the RINEHART 400V and no LSD. Battery wise I have 5 X Tesla Module 24V 250Ah 5.2 kWh in mind. Starting to draft different options on how to fit all of these in the mini. 

CHEERS


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## brian_ (Feb 7, 2017)

Scanales said:


> Thanks @brian_ and @pickmeup for the info.
> 
> It’s the same 80kW motor. I will be going for the RINEHART 400V and no LSD. Battery wise I have 5 X Tesla Module 24V 250Ah 5.2 kWh in mind.


That makes sense, except that regardless of the inverter you still won't have enough voltage available, because of the battery choice. The controller/inverter does not step up voltage (except in the rare case of some Toyota hybrid vehicle controllers that have a voltage doubler ahead of the inverter stage), so what you can get to the motor is limited by what comes out of the battery. Performance will be worse than shown for 144 V, because voltage is even lower.

This assumes that you are not modifying the Tesla modules. Converting them to 12S and using 10 would give you about 225 V (nominal)... still not enough for best performance, but maybe okay.

Note: the Tesla modules have a nominal voltage of about 22.5 V (so 5 modules would be 113 V), with actual module voltage varying from as low as perhaps 18 V to as high as 25 V or so at full charge. People who think everything in DC power must be a multiple of 12 volts tend to round this up to 24 volts, but these are not lead-acid cells so nominal voltages are not a multiple of 2.


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## Scanales (Apr 13, 2020)

Yes! I’m aware of this problem. I’ve been reading on this modification to the tesla modules, however it seems to be to much input and just half the solution.

Any other suggestions for this issue?


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## Scanales (Apr 13, 2020)

Scanales said:


> Yes! I’m aware of this problem. I’ve been reading on this modification to the tesla modules, however it seems to be to much input and just half the solution.
> 
> Any other suggestions for this issue?











These are 60V but fitting 8 of them in the mini seems tough. The form factor in the tesla modules seem more favorable.


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## brian_ (Feb 7, 2017)

Scanales said:


> I've been reading on this modification to the tesla modules, however it seems to be to much input and just half the solution.
> 
> Any other suggestions for this issue?


Different modules.

The ~60 V example is presumably the 16S LG Chem module designed for the Chrysler Pacifica Hybrid, and sold by various EV conversion companies. You would only need six for 360 V nominal; that would peak at close to the 400V inverter limit at full charge, but only give you about 16 kWh. That is typical plug-in hybrid rather than EV capacity, but might be enough for the Mini. If you can't fit in six of those, I don't know how you fit in five of the Tesla Model S/X modules (since the LG modules are only 3/4 of the volume of the Tesla modules, and the longest dimension is not much more than half as long), but what fits in is to some extent a matter of how the rigid dimensions of the modules go with dimensions of the available spaces.


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## Scanales (Apr 13, 2020)

brian_ said:


> Different modules.
> 
> The ~60 V example is presumably the 16S LG Chem module designed for the Chrysler Pacifica Hybrid, and sold by various EV conversion companies. You would only need six for 360 V nominal; that would peak at close to the 400V inverter limit at full charge, but only give you about 16 kWh. That is typical plug-in hybrid rather than EV capacity, but might be enough for the Mini. If you can't fit in six of those, I don't know how you fit in five of the Tesla Model S/X modules (since the LG modules are only 3/4 of the volume of the Tesla modules, and the longest dimension is not much more than half as long), but what fits in is to some extent a matter of how the rigid dimensions of the modules go with dimensions of the available spaces.


Yup, thats it. 6 I could fit. Ideally I want 20kWh for the mini. I can do some fitting and weight distribution exercises with this info


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## Tremelune (Dec 8, 2009)

If you want higher voltage, the cost is money, weight, and space. There's no great way to get high voltage with less weight...Prius and Tesla/Smart battery packs have high voltage per pound/liter, but the former lacks range and the latter costs a lot. Well, arguably. You can buy a Smart Fortwo ED in good condition for about $5k, netting you about 18kW and 350V in a ~300-pound pack.

If I were you I'd try and put half the modules up the middle above the exhaust tunnel, and half under the rear seat (this is what Swindon does)...and just...add more...

My car just has 30 Leaf modules sitting on the rear seat. Weight distribution is looking like it will be between 50/50 and 55/45 front/rear, and total weight is maybe 200-300 pounds up from stock. Considering this car was (somewhat) designed to have rear passengers, I think you'd be good if you're willing to lose those seats. Might still be good by putting aTesla module or two between the front seats and one or two in the boot.


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## brian_ (Feb 7, 2017)

Tremelune said:


> Might still be good by putting a Tesla module or two between the front seats and one or two in the boot.


A Tesla Model S/X module is 302 mm (one foot) wide, so standing on edge it would be 302 mm tall, plus the housing. Would you really put that between the front seats? Two of them would be 160 mm thick, plus the housing - that's a lot to go between Mini seats, too.


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## brian_ (Feb 7, 2017)

Scanales said:


> Yup, thats it. 6 I could fit. Ideally I want 20kWh for the mini


If you were thinking of 8 modules to get that 20 kWh... no, that won't work, because the peak voltage at full charge would be way beyond the controller's 400 V limit. That controller limit is designed to work with typical 96S battery configurations, not the 128S of eight of those 16S LG modules.


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## Tremelune (Dec 8, 2009)

I'm thinking of the packs from the Smart Fortwo Electric Drive:





__





Tesla Smart Lithium Ion Battery 18650 EV Module - 57 Volt, 3kWh, EV West - Electric Vehicle Parts, Components, EVSE Charging Stations, Electric Car Conversion Kits






www.evwest.com


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## brian_ (Feb 7, 2017)

Tremelune said:


> I'm thinking of the packs from the Smart Fortwo Electric Drive:
> 
> 
> 
> ...


Right - you mentioned that before, but I forgot that and assumed the usual Tesla Model S/X modules. Of course the 184 mm height of these Smart ED modules would be much more appropriate between the seats than the Model S/X module on edge. Maybe a stack of two could be tolerable...


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## Tremelune (Dec 8, 2009)

Random thought: There's like an open block under the boot (twixt the rear subframe) that isn't the lowest part of the car, and is only blocked by the recessed battery box in the trunk. Might be a spot to get a pair of modules if they fit and if you're willing to build a box to protect them. Nice and low, and half in front of the rear axles.


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## pickmeup (May 8, 2018)

ive been contemplating creating a battery box that would locate into the rear subframe, and delete the original 12v battery box thats in the boot floor.
Ive had a quote from electric classic cars in the uk as they import the LG Chem battery cells but they are far too pricey so lookign at the mitsubishi outlander battery pack or the vw hybrid battery pack.


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## schelle63 (Jan 3, 2018)

Expanding the rear battery-box is what I did in the boot. Very easy and effective. The other pack is located under (not between) the front seats. This is somewhat tricky, but feasible.
However there is weight missing on the front axle now. In my current conversion project I am locationg one set of batteries is in the trunk.
Markus


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## Scanales (Apr 13, 2020)

Tremelune said:


> I'm thinking of the packs from the Smart Fortwo Electric Drive:
> 
> 
> 
> ...


Is 7-8 of these feasible with the 400V controller?
Just lowered the rear subframe this weekend. Expanding the battery bay seems doable.


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## Duncan (Dec 8, 2008)

With my old mini decades ago I threw the rear subframe away - instead I used a single bar across the back that carried the rear swinging arms and used coil over shocks with some reinforcing of the rear shock mounts - not a lot is needed the shock absorber peak loads are already higher than the spring peak loads
This gets shot of a rust monster and will give lots of space


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## pickmeup (May 8, 2018)

Duncan said:


> With my old mini decades ago I threw the rear subframe away - instead I used a single bar across the back that carried the rear swinging arms and used coil over shocks with some reinforcing of the rear shock mounts - not a lot is needed the shock absorber peak loads are already higher than the spring peak loads
> This gets shot of a rust monster and will give lots of space


I fitted a couple of these "beam axles" over the years and it made the rear end of the mini very skittish, hence why none of the race series currently use them.

Saying that i may look into it on the mini marcos if i can integrate the roll cage into mounting all the rear points and the large battery box im planning. But it will need properly setting up of the corner weights and me cutting and grp'ing some new rear towers in.


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## Scanales (Apr 13, 2020)

I started the body work process today. Just before that, I played a bit with some fast measurements for the battery placement in case I settle down for the Tesla/Smart 18650 modules. According to the measurements I found online I settled on a nice space for 6 them, would love to have 7.

First two go side to side between the driver and passenger. I will flatten out the exhaust tunnel for this. This was done in swindons mini and the final resulta does not bother me at all. I will need to find a new place for the hand brake, for the shifter a will be using buttons on the dashboard.

















The second couple of modules go underneath the rear seats, laying on their tall sides. stacked on on top of the other.
The flat floor will help, I will need to modify the support for the rear bench.










Finally. As suggested by @pickmeup I tried expanding the original battery box in the back. However this long modules wouldn’t fit with out messing with the sub. For other types of modules seems like a great solution, for me I will try to place some of the other components in there (Charger maybe?). Instead I will lay two modules next to each other and place the ”bottom“ of the trunk on top of them, I should have a good amount of available space in the trunk.


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## pickmeup (May 8, 2018)

one of the issues i have with the swindon powertrain conversion is the new "exhaust tunnel" as in the UK if there are any modifications to changing the bodyshell it can be subject to an IVA inspection, which is something i would like to stay well clear of.
I do think the rear battery box would be ok but i would look at strengthening the boot floor and tieing it in with the rear suspension mounts.





  








post-122005-0-21304300-1543077452.jpg




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pickmeup


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Jul 13, 2020








As my conversion is going to be on a mini marcos i have the added fun of it being made out of varying thickness GRP, so will look at building a complete rollcage with the battery boxmounts tied into it.





  








32748903_1805636556126400_1999109179511406592_n.jpg




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pickmeup


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Jul 13, 2020








I must admit for an 89 mini it looks in good shape and at least you dont have to weld a load of new panels in to cut them back out!


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## schelle63 (Jan 3, 2018)

Scanales: You can add considerable space under the rear seats by cutting out the seat's support panel and reinstall it horizontally. You will need to ad a narrow vertical strip from left to right, and to cut out a wedge from the seat's foam. This measure is invisible, and even the rear passengers won't notice it when sitting there. I can post a picture, if required.
Markus


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## Scanales (Apr 13, 2020)

schelle63 said:


> Scanales: You can add considerable space under the rear seats by cutting out the seat's support panel and reinstall it horizontally. You will need to ad a narrow vertical strip from left to right, and to cut out a wedge from the seat's foam. This measure is invisible, and even the rear passengers won't notice it when sitting there. I can post a picture, if required.
> Markus


Thanks Markus!
Sounds similar to what I had in mind. I would really appreciate if you could share some pictures.

cheers


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## schelle63 (Jan 3, 2018)

...et voilá...


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## Scanales (Apr 13, 2020)

That’s perfect! Thanks for sharing @schelle63. I will definitely consider this mod.


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## pickmeup (May 8, 2018)

Ive never seen that done before in all my years working on and owning minis. great solution though.


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## schelle63 (Jan 3, 2018)

Thank You. Oddly enough that space is currently not used, as the car has the expanded battery tray in the trunk and a largely expanded cross-tunnel under the front seats. But some day this may be an option...
Again, remember not to make the car too light on the front. Spinning wheels are useless (ok, some people like that), I assume it is real acceleration most of us are looking for.
Regards,
Markus


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## Scanales (Apr 13, 2020)

Hi all,

I’ve been looking for different options regarding Air-conditioning? Some seem far more expensive than others. Wonder if its possible to use a unit from a Leaf. Want to be as efficient as possible. I saw a similar unit to the one below being installed in a EV Conversion in the Vintage Voltage show, however it seems really expensive.









Electric Air Conditioning for Classic 911 (single condenser)


• NOTE CURRENT LEAD TIME OF 6-8 WEEKS • All kits now include our Gen 2 Blower. The Electrocooler electric air conditioning system for Porsche 911 is a revolutionary update for the complicated A/C and ventilation setup fitted to Porsche 911 models from 1974 to 1989. The kit is a total redesign...




www.classicretrofit.com





Any suggestions?


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## brian_ (Feb 7, 2017)

Scanales said:


> I’ve been looking for different options regarding Air-conditioning? Some seem far more expensive than others. Wonder if its possible to use a unit from a Leaf. Want to be as efficient as possible. I saw a similar unit to the one below being installed in a EV Conversion in the Vintage Voltage show, however it seems really expensive.
> 
> 
> 
> ...


Interesting... that one uses up to 50 amps of 12 V DC power. If the 12 V DC is coming from a DC-to-DC converter, it would seem more optimal to use the power directly a HV battery voltage; however, even 50 A @ 12 V is less power than I expected. Given that it's for a 911, and is intended to improve only on the likely marginal system in a half-century-old sports car, it might not have a lot of cooling capacity.


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## Tremelune (Dec 8, 2009)

I've been exploring this myself:









Electric air conditioning compressors


Does anyone have a converted car with electric air conditioning working well? I'm specifically not interested in belt-driven systems, as the complexity involved with driving them outweighs their low cost. On the high-end, it's a solved problem with a 15k+ BTU aftermarket compressor for around...




www.diyelectriccar.com


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## Scanales (Apr 13, 2020)

Hello Everyone!

So some pretty big changes since my last post.. I’ve decided to ditch the TESLA/ SMART CAR battery packs for this project (Will definitely find somewhere to use them).

I’ve decided to go for the new OX-Drive batteries from Electric GT, also some second thoughts on battery placement and modifying the exhaust tunnel, instead, I’m entertaining the idea of having two packs under the rear seat, 1 pack on each rear side compartment, one under the bonnet and one on the trunk.






Any thoughts on this arrangement?

Cheers


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## Tremelune (Dec 8, 2009)

How many kWh is that?

Space in the engine bay is tight, but if you ditch the brake booster a lot of space frees up. It seemed like a real pain to get a useful amount of Leaf batteries up there, but it seems like maybe the OXT batteries will fit. I wonder if you could get two...

What's the motivation to keep the rear seat? I put a 200lb guy in the back of mine once, and the car was almost dragging on the bump stops...

Trunk space is ample.


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## Scanales (Apr 13, 2020)

21.3 kWh. It’s 6 of them. 4 back seat and sides, one in the trunk and hopefully one in the front. 

No real practical motivation for keeping the rear seat. Would be nice to have, It can go if we have an issue finding space for the batteries. I thought a slight mod on the side compartments could help us gain some battery space and keep the seat, that’s all.


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## schelle63 (Jan 3, 2018)

It is good to put some weight back into the engine bay. Keeping the rear seat keeps the orginal look, which I like. Consider that passengers there also need some space for their feet, I don't see that in your picture. If possible try to put the batteries of the side compartment down into the pockets, instead above them. And some batteries do fit under the front seats.
Of course you will need to split your current modules again...it is like in real life: you get nothing for free.
Markus


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## Duncan (Dec 8, 2008)

Look under your car at the back
If you remove the rear subframe - which you can do if you use coil overs and reinforce the rear wheel arches
There is a lot of wasted space under there


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## McGeesCustomMinis (Oct 26, 2020)

Sent you a message Sir.


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## schelle63 (Jan 3, 2018)

Converting the rear suspension in that way might be good if you look for ultimate performance.
Installing too much weight in the car's back, is certainly unfavourable.

Markus


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## McGeesCustomMinis (Oct 26, 2020)

schelle63 said:


> Installing too much weight in the car's back, is certainly unfavourable.
> Markus


Curious, it seems that a lot of aftermarket companies, or diy people either 1. Ditch back seat and stack batteries there in a classic mini 2. My preferred method would be recessing the rear boot floor and not loosing your back seat... 

But what kind of weight are we talking about here? It seems in most scenarios:

1. Lets say 5 Tesla S batteries in the boot. That's roughly 285lbs and whatever structure you make to support it.
2. Motor 120lbs, gearbox 70lbs, frame 40lbs, controller, etc ~230lbs
3. Stock a-series engine/gearbox ~350lbs
4. Add wiring, radiator, pump, etc

Using Tremulune's numbers:

Stock was 1,575lb 64/36.
EV setup with leaf: 1,650lb 56/44

Is this really a bad thing? What am I missing?


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## brian_ (Feb 7, 2017)

McGeesCustomMinis said:


> Stock was 1,575lb 64/36.
> EV setup with leaf: 1,650lb 56/44
> 
> Is this really a bad thing? What am I missing?


It's not terrible in either total mass or front/rear distribution, but the rear mass is all overhanging beyond the rear axle line, which is undesirable for handling response in a short-wheelbase vehicle. Also, the driver and any passengers are behind the midpoint of the wheelbase, so weight distribution will be more rearward than the empty values.


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## schelle63 (Jan 3, 2018)

My mini probably has a very similar weight distribution to Tremelune's conversion. Actually, it was my intention to equalize front/rear distribution to a certain degree. Cornering ability, especially through roundabouts, has become spectacular. However I have limited acceleration (nominal 27kW only!) because front wheels are spinning. (Tyres: 165/70R10 Yokohama A032)
Would be interesting to learn if Tremelune could confirm this impression, or not.
I consider my car's current balance as a mistake, meanwhile.
Next project will have it closer to stock. If ok., I may modify the first car accordingly.
This is my personal experience and what I have learned from. And-of course-following my personal preferences.
Markus


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## brian_ (Feb 7, 2017)

schelle63 said:


> ... it was my intention to equalize front/rear distribution to a certain degree. Cornering ability, especially through roundabouts, has become spectacular. However I have limited acceleration (nominal 27kW only!) because front wheels are spinning.
> ...
> I consider my car's current balance as a mistake, meanwhile.
> Next project will have it closer to stock.


I agree, unfortunately. A car with equal load on front and rear axles and two wheel drive should certainly drive the rear wheels, not the front.

Production EVs adapted from front-wheel-drive conventional vehicles have some of the same problem for the same reason of replacing a front engine and transaxle with a lighter motor and transaxle plus battery centred behind the midpoint of the wheelbase. The original Nissan Leaf's odd rear shape wasn't just the funky French-Japanese styling - it minimized rear cargo capacity and rearward length of the cargo compartment to avoid overloading the rear axle; it even has a completely empty space under the rear cargo floor where there should be a spare tire well or hidden cargo compartment, but they didn't want any more load back there.


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## Tremelune (Dec 8, 2009)

My car's acceleration is for sure limited by traction up front, but...it's still quite the little monster. Not having experienced the insanity of a Honda B conversion, maybe it's tame, but...moving to rear or AWD would take _quite_ a bit of work, and even then you'll introduce the fun of accidental throttle-induced oversteer. Crazier Minis have been built, but they often come with the disclaimer that maybe they went too far beyond the fun zone. I choose to be content with some throttle modulation until 30mph or so.

I'm of the mind that I worried about weight distribution too much for scooting around the city (which is the purpose I built it for). It sure does well on Mulholland Drive, which is nice. That said, I'm not sliding around on public roads, so I can't tell you how it feels at the limit.


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## schelle63 (Jan 3, 2018)

@ Tremelune:
It's a pity that most probably we will never have a trip along Mulholland Drive together with our Minis, or experience where each other's limits might be.


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## Duncan (Dec 8, 2008)

People taking about minis and traction limits
The unfortunate truth is that the mini suspension and handling is deceptive

With a small amount of power a mini feels GREAT!
If you get a bit more power its really not very good!

My 1430cc mini with about 110 hp was well over the optimum

When I changed the front suspension and fitted a 2 litre Lancia engine with Hollbay Cams and twin webers I went from 110 hp to over 170 hp 
AND it had MORE traction

I really like the mini suspension - but its not very good if you have over about 70 hp


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## schelle63 (Jan 3, 2018)

pickmeup said:


> i have seen some other information about the swind e motor and they do have to cut into the rear of the subframe and there is some extra brackets required for mounting points.
> 
> 
> the only photo ive seen on the internet with the motor in the subframe is this one below.


There is more info about swindon, meanwhile:








Swindon Powertrain Will Sell You A Mini EV Convertion Kit For $11,500


Swindon Powertrain now has a classic Mini EV conversion kit for £8,850 ($11,500). It’s cheaper than the Swind E Classic Mini, but where’s the battery pack?




insideevs.com




I just had a déja-vu regarding the motor/subframe picture.
Not really cheap, however.
Markus


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## brian_ (Feb 7, 2017)

If find it interesting that the Swindon conversion, now that it has reached commercial product stage, places a 12 kWh battery pack right on top of the motor. The resulting weight distribution will be even more front-heavy than a stock Mini, and if someone used that pack plus an additional rear pack (or two custom packs of similar total capacity and locations), the weight distribution would probably be reasonable.

Most conversion components, whether a conventional transaxle plus typical motor or a more integrated electric drive unit but from a larger front wheel drive car, will not leave enough space for a battery pack on top.


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## schelle63 (Jan 3, 2018)

Must be a very (!) compact battery. On the current project, I managed to install 8kWh only on top of the motor.
The reason might be that the old-fashioned Siemens-controller requires much space there.


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## brian_ (Feb 7, 2017)

schelle63 said:


> Must be a very (!) compact battery. On the current project, I managed to install 8kWh only on top of the motor.


This is an excellent point - there really isn't enough space there for a battery which either holds 12 kWh of energy or can effectively power an 80 kW motor, let alone both. Plug-in hybrids have relatively power-dense batteries of about this capacity, and they're much larger (e.g. Chevrolet Volt, Chrysler Pacifica Hybrid, Mitsubishi Outlander PHEV); battery-electric vehicles tend to a higher energy density but a BEV battery of this size typically can't handle this power output.

Something seems fishy, but maybe I should dig out actual measurements of the space.


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## pickmeup (May 8, 2018)

As soon as lockdown is over again in the UK im visiting them for a test drive. They were working with a UK battery specialist for the initial prototypes called MEP Technologies.


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## schelle63 (Jan 3, 2018)

pickmeup said:


> As soon as lockdown is over again in the UK im visiting them for a test drive....


hopefully earlier than 2022!


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## scottherrington (Jul 3, 2020)

Nice to see another mini conversion 
I have the same issue with the batteries, I still think the Zoe batteries will be easier to fit in but I too am trying to keep the rear seat. The main issue now is intrusion into the rear foot space as seen in your photos.
You can see some of my battery ideas on my Instagram page mini_life_crisis1996


Sent from my iPad using Tapatalk


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