How much would I have to pay for a decent electric motor and battery?

mr chips

I'm mulling over a possible EV project, involving a spare vehicle that would only be used 2-3 times a week and is purely for fun.  My theory is that when it's not in use on the road, it could be used as a sort of mobile powerwall, meaning we would benefit more from our 14 panel solar array - which generates a surplus over & above our household needs during daylight hours from mid-February to early November - so that we would be able to use more of that power even after the sun goes down, thereby importing less from the grid overall.

But I would still want the range and energy density of a modern EV battery so that I could still do 150-200 miles on a charge - vehicle weighs less than 500kg with an ICE engine, so this isn't necessarily overambitious - and still have similar (or hopefully better!) levels of performance in terms of acceleration, top speed, fast charging etc.  Is it even possible to buy the likes of a Tesla/Leaf/Ioniq battery as a separate unit?

Plus if anybody has suggestions about sourcing a suitable motor, I'd welcome that input too.  Dunno yet whether it would be possible to just use the likes of a big forklift or other "industrial" motor, or if I'd need something with more oomph - I'd want to be able to cruise at 85-90mph for a couple of hours without difficulty.

Might all be daft but I think it's worth at least exploring and tossing a few ideas around.

If you search for insideevs.com for Lotus there are some articles about somebody electrifying an Exige using Tesla motor and some GM batteries. At speakev.com there is an interesting thread about electric Porsche 911 project. Forklift etc. motors are oldskool and not really suitable for a sports car. It won't be an easy project for sure. You need lots of parallel cells and high voltage for good performance meaning the battery cost won't be cheap.

For 200 mile range think of €10k+ for the battery.

DublinDilbert

Is the vehicle front wheel drive? Use a prius trans-axle with the two motors built in.

The motor controller is likely to cost as much as the battery pack.

I would be looking in to getting a used EV battery pack or an old pack from a prius (even just for testing as it will only give you a couple of KM range). Your going to need a charger too.

Its a nice thing to do with a classic car with a bad engine, i would love to do an E(v)30 BMW.

Del2005

I'd guess that the biggest issue you will run into is getting insurance. They don't insure a lot of cars with extras you are going to be completely replacing the power source and engine. See if you can get insurance before spending any money.

ELM327

Del2005 wrote: »

I'd guess that the biggest issue you will run into is getting insurance. They don't insure a lot of cars with extras you are going to be completely replacing the power source and engine. See if you can get insurance before spending any money.

If it's a classic there may not be so many issues

zilog_jones

DublinDilbert wrote: »

Is the vehicle front wheel drive? Use a prius trans-axle with the two motors built in.

How does that work then? The Prius is not very powerful with just EV power, and MG1 isn't normally driving the wheels (it's either starting the ICE or being driven by the ICE to charge the batteries) - or can it be repurposed/modified to assist MG2 and provide more power?

mr chips

Thanks for those replies folks, some real food for thought there.  Battery cost sure looks like the biggest barrier right now, if €10k is the sort of money I'd have to spend.  Any tips on trying to track down a used one?
To answer some of the questions & provide a little more detail, the vehicle is a trike - a mongrel made of a stretched Harley Sportster frame at the front and a VW Beetle rear subframe & gearbox.  The interior space of the bike frame is either hollow for storage (easily big enough to fit a bike helmet in that part) or contains an extra fuel tank, which could of course be removed to make way for a battery or two.  In fact, even the fuel tanks themselves could be removed to make way for batteries (depending on their dimensions) and covered with dummy fuel tank units to preserve the appearance.
Mounting a motor onto the gearbox wouldn't be difficult - I could either use the existing mounting plate or have another one made up.  The engine that's currently in there is a 90hp DTurbo which I used to run on biodiesel (hence the username - the smell from the exhaust was like a takeaway!) but which I have to run on ordinary diesel now.  That engine's 150kg dry weight, so replacing it with an electric motor would probably save me 100kg at least.  This would make it a very lightweight vehicle, meaning that an electric motor wouldn't have to be the size of the one in that Lotus Evora to make it go as fast as it currently does.  It's rear-wheel drive, obviously, and while I'm restricted to the gearbox I have I can easily change the wheels & tyres for bigger diameter ones to give me longer gearing and a higher top end.
I'm based in NI, so have access to some specialist insurers which don't operate in the south.  One such is Adrian Flux, which specialises in customised/non-standard vehicles, and I've used them for years without difficulty so hopefully that shouldn't be an issue.
Keep the suggestions coming, especially regarding battery & motor options - you never know, I might make this happen yet ...

Bigus

Buy a complete written off leaf , no need to reinvent the wheel just re-package it.

positron

You might have seen this already, but jist in case if you haven't, Wheeler Dealers electric Maserati project episode on YouTube was very good, end result was amazing, they have some details on type of motor, costs etc as well.

I would love to something similar with a motorbike, but I dont have the skills or knowledge.

air

I'd suggest that 80-90mph for a couple of hours is actually an impossible goal for a vehicle like that with current battery energy density - irrespective of budget.
I'd imagine that it has terrible aerodynamics and would probably use 30kW+ at those speeds.
If you are happy with lower range it should be doable repackaging an existing crashed EV as has been mentioned.
I'd say you'd be looking at 10-15k and a few hundred hours of work to get it done though.

mr chips

Haha, I suppose doing 80mph for a couple of hours would be impossible if I only had a 120 mile range alright!! I can't honestly say with certainty what the aerodynamics are like in terms of coefficient of drag etc - obviously I've never ridden in a wind tunnel, even though it may occasionally feel like that ... It might not be as bad as you imagine though. At its highest point, the machine is about 35-40cm lower than an average car, and of course it's no wider than an old VW Beetle, i.e. 180cm at the rear wheels (which with mudguards above are 80cm high from the ground). So there's a much smaller surface area pushing through the air than there would be on a car. Plus it has a streamlined bodyshell covering the rear - this forms the back seat and covers the engine, tapering in from 110cm wide/125cm high at the widest & tallest point, to 90cm wide/110cm high at the very back. Where I tend to notice the wind at higher speeds is that it pushes at my crash helmet, as the front end is "naked" - that said, it wouldn't be difficult to put a small windshield between the handlebars which would help to direct airflow up & over my head.

In terms of hours, if I had a buddy working with me it would take a bit less than an hour to remove the bodyshell, the current engine & starter and the radiator, maybe another half hour to remove the fuel tank contained within the bike frame.  I've to do some of that to replace the gearbox anyway with my new "SuperBeetle" one, so there's no loss to me there. Getting a mounting plate fabricated would be maybe £100 at most, less if I find the right person to do it for me. Ditto mounting brackets for batteries, motor etc.

In theory, I'd be aiming for a sort of T-shape layout, one or two battery modules inside the bike frame and two or four above & behind the rear axle. Space inside the bodyshell should be more than adequate for an electric motor plus batteries - any electric motor I've seen so far seems to be a fair bit smaller than what I've got in there right now, especially once I remove the intercooler/turbo/exhaust/fuel pump etc.  Including those peripherals, the engine itself is about 60cm front to back, 70cm side to side and 70cm top to bottom, with an additional 8-10cm of space available on either side (i.e. up to 20cm in total).

I guess a lot of this will depend on the size & dimensions of batteries. Anybody able to guide me there?

air

Look up the volumetric energy density of lithium polymer batteries and that'll give you a kWh/L figure to work off. I can't recall it off the top of my head.
Nissan Leaf modules are approximately A4 sized and are about 35mm thick. There are 48 of them in a pack and they store about 0.5kWh each (for the 24kWh model). They weigh about 4kg each which puts the pack at 200kg more or less before you add packaging etc.
The main issue with them for an application like yours will be their physical size.
Something like the modules from a Golf GTE might be better suited. They're physically smaller so you could split the pack up a bit better potentially and make use of some otherwise unused areas. You might have to buy a few packs as the total pack is only just over 8kWh.

They are also used at much higher power levels in the donor vehicle (10C discharge) vs about 3-4C rate for the Leaf cells.
Bear in mind also that the battery pack will kill you no problem if you don't know what you're doing during assembly, maintenance etc.

mr chips

That's very good to know, thanks for that. When it comes to assembly/maintenance of the battery modules, I'd be handing over to someone else for exactly the reason you mention. I don't fancy being a fried chippy!

If for the sake of argument I ended up going with the Nissan ones, I have about 30cm(W) x 30cm(H) x 60cm(D) of space available to me inside the bike frame section, so assuming they could be stacked side-by-side rather than one on top of another then I could probably get 16 modules in there. In theory, of course!!

The amount I could fit under the bodyshell and more or less above the rear axle (an important consideration for weight distribution) would depend on the width of the electric motor - what would I need to allow for that?

air

Yes, they can be stacked side by side, they're used like that in the car and if you buy a full pack you'll get top and bottom plates that will facilitate just that arrangement.
You'll just need to get some threaded rod to facilitate connecting them together.

I can't help too much on the motor side unfortunately, there's a wide range of different models available.
Remember you could probably get rid of your gearbox too though and just use a differential, might save you further space and weight.

mr chips

Hmmm ... never thought of that at all! If I were able to dispense with the gearbox then at least another 6-8 modules could go in its place, maybe more.  Of course, the greater the number of battery modules I could squeeze in there, the further I could go on a single charge ...

Thanks a million for all that, it's certainly a lot of food for thought.  To be honest it's not likely to be a project I take on until next year, or at least until the winter time when the trike wouldn't be on the road much anyway.  But the more I think of it, the more I want to do it ...

DublinDilbert

zilog_jones wrote: »

How does that work then? The Prius is not very powerful with just EV power, and MG1 isn't normally driving the wheels (it's either starting the ICE or being driven by the ICE to charge the batteries) - or can it be repurposed/modified to assist MG2 and provide more power?

MG2 is enough to power the Gen2 prius up to speed no problem. With MG1 also been driven as a motor there would be no lack of power. You would need to "lock" the engine shaft in position so the planetary gear set would work correctly.