EV conversions

[Snagger]

5 hours ago, Badger110 said:

This popped up on YouTube and mentions Jaunt @snagger  as supplier of their kits

 

 

If you go to their website, prices are notably missing.  It’s one of those “if you have to ask the price” situations, but the FAQ page says that a small simple car with less than 100 miles range could cost around £30k to convert and a “large 4x4 with 200 miles” over £100k.  That is for the conversion, excluding the base vehicle.

Therein lies the problem with Tesla based conversions.  Don and Jaunt have tried to be far thriftier, hence their motor choices and the use of the original transmission, but range is still a problem regardless.

[FridgeFreezer]

I've seen their EV conversions, I think they were the guys that did the thing with Guy Martin?

It just makes me nervous that they're pretty much pulling battery packs out of Teslas, wiring up a load of aftermarket controls & charger etc. to them and calling it good... given the insane complexity & R&D effort in EV battery packs, and the ways they can go spectacularly wrong, it gives me the heebies... sort of the modern equivalent of shonky LPG conversions that were always full of scotchloks & plumbing fittings.

[Snagger]

A lot of companies using Tesla batteries unpackaged and remounted use their own “daughter board” electronic BMS cards for each battery pack as the Tesla card won’t interface with the new controllers and main BMS, especially with the cooling systems removed.  They seem much less complex to the eye than the original cards.  That makes me nervous like you, John.  I’m pretty sure they don’t allow “supercharging” like the packs were originally capable of, but I still worry about their thermal management when really pushing the car hard or when rapid charging.  Even if the batteries don’t get hot enough to pose a fire risk, I’d imagine their capacity is being diminished far more rapidly on each charge than with the original BMS.  Other companies use uncooled battery packs  like on the Leaf, which are self limiting in their charging and delivery rates and wouldn’t have the gusto to power a Tesla motor, but their charge times suffer and first generation Leaf batteries had significant deterioration due to the poor thermal management.

Given the cost of the batteries, the main cost in these conversions, poor thermal management and rapid battery deterioration is going to bite the owners and intimately the conversion companies in the backside if they aren’t very careful.

[cackshifter]

Ignoring the technical aspects for a moment, it's probably good there are some conversions being done inasmuch as it establishes the principle of doing it, as possibly there may be moves made to outlaw such changes. There may still be of course!

[deep]

8 hours ago, cackshifter said:

Ignoring the technical aspects for a moment, it's probably good there are some conversions being done inasmuch as it establishes the principle of doing it, as possibly there may be moves made to outlaw such changes. There may still be of course!

Agreed!  If you subscribe to the point of view that electric vehicles are good for the planet, conversions are going to be a better thing, as there is less waste involved than manufacturing a vehicle from scratch and then shipping it.  If we think in terms of personal transport, rather than heavy working vehicles like Land Rovers, a small car with a modest power output and "round town" kind of range could be, relatively, very low impact to convert.  Trouble is, most of those are now front wheel drive with layouts not necessarily conducive to tapping into an electric motor.  And it takes us off topic on a Land Rover forum...

[simonr]

10 hours ago, deep said:

Trouble is, most of those are now front wheel drive with layouts not necessarily conducive to tapping into an electric motor.  And it takes us off topic on a Land Rover forum...

Front wheel drive is no more difficult than RWD to convert.  The engine still unbolts from the gearbox - and you just bolt a suitable motor in it's place.  For a vehicle with limited range, removal of the engine frees up enough space for the batteries to live under the bonnet.

The biggest hurdle to (most) people converting a newer car is hacking the CANBUS such that the vehicle, in particular things like ABS & Power Steering continue to work.  However there is a lot of info on line for people with a little cleverness to make it work.  I can see, in the future being able to buy black boxes which will do this.

 

[reb78]

If someone produced a DIY fittable but properly and safely designed plug and play kit for my 110 I would consider it in the future. I would think our land rovers ought to make for a very easy conversion and have space for batteries to give a good range too

[Ed Poore]

Also the aerodynamics of a brick... 

[reb78]

21 minutes ago, Ed Poore said:

Also the aerodynamics of a brick... 

how much difference does it make in reality? Genuine question, always wondered really. I know it will help to be more aerodynamic but how much?

[Ed Poore]

27 minutes ago, reb78 said:

how much difference does it make in reality? Genuine question, always wondered really. I know it will help to be more aerodynamic but how much?

Massive with increased speed.

I did have the calculations somewhere that for a Defender to get to 60mph it required about 40-50hp, to get it to 70mph required almost the same again. Hence why for ~110hp a Tdi has you struggle to attain much more than 85ish mph reliably.

I can't remember the exact relationship for air resistance but it certainly goes up as a cubic if not the quartic relationship to speed.

[Ed Poore]

Should say that's the power required to sustain that speed, not get to it. You need a bit more for that to do it in any reasonable time.

So 50hp is about 37kW so to sustain 50mph for an hour in a Defender you're burning through that an hour just to sustain the speed. Cruise at 70mph and you're doubling the energy consumption.

[Bowie69]

Yep, massive difference.

Why do you think all the EVs out there are covered in plastic tat above and below?

[Snagger]

On 5/27/2022 at 4:43 PM, cackshifter said:

Ignoring the technical aspects for a moment, it's probably good there are some conversions being done inasmuch as it establishes the principle of doing it, as possibly there may be moves made to outlaw such changes. There may still be of course!

Progress is almost always incremental, and the folk taking these first steps are laying the groundwork for what will follow.  As expensive and as compromised their solutions are, they are essential to finding a way to make this viable for more of us.  I’m as impressed as I am grateful for their persistence and ingenuity.

[FridgeFreezer]

5 hours ago, Ed Poore said:

I did have the calculations somewhere that for a Defender to get to 60mph it required about 40-50hp, to get it to 70mph required almost the same again. Hence why for ~110hp a Tdi has you struggle to attain much more than 85ish mph reliably.

@TSD had a spreadsheet that worked it out I think - it's pretty much an exponential curve the faster you go and does give the lie to some of the claims you hear in the pub about how fast people's Defenders will go

[cackshifter]

Drag in a fluid used to increase with the square of speed, so 70mph is about twice the drag of 50. Of course there are other things like bearing friction and tyre rolling resistance but at any sensible speed drag is the overwhelming resistance.

[Ed Poore]

1 hour ago, cackshifter said:

Drag in a fluid used to increase

Used to? What about now?

[deep]

12 hours ago, simonr said:

Front wheel drive is no more difficult than RWD to convert.  The engine still unbolts from the gearbox - and you just bolt a suitable motor in it's place.  For a vehicle with limited range, removal of the engine frees up enough space for the batteries to live under the bonnet.

The biggest hurdle to (most) people converting a newer car is hacking the CANBUS such that the vehicle, in particular things like ABS & Power Steering continue to work.  However there is a lot of info on line for people with a little cleverness to make it work.  I can see, in the future being able to buy black boxes which will do this.

 

That's on the understanding that you keep the gearbox.  More efficient electric vehicles pretty much avoid that (not sure which would have a step down or step up gear on the motor though), hence my comment.  But sure, a simple conversion keeping the gearbox would be fine in FWD.  If you get rid of the box, rear wheel drive is so simple.  I'd be far more interested in converting something that didn't have ABS, power steering, air con or draconian computer control!  I guess that is what is considered a "classic" these days but I was thinking more in terms of the wonderful little eighties hatchbacks I used to own, or something into the nineties.  I wonder how new you could go without encountering the computer version of Big Brother?

I'm intrigued by the concern for aerodynamics.  No practical difference to petrol or diesel, surely?  Land Rovers will always be more economical driven at Land Rover speeds, no matter the motive power!  (Though I will note the electric version of the Ford F150 is more aerodynamically efficient than any of the other versions.)

[Bowie69]

No different to petrol and diesel other than maximising range is about the most important selling point for an EV.

Obviously doesn't concern petrol/diesel users because a fill up only takes 5 minutes.

[Ed Poore]

Also the energy density of diesel is waaaaay better than lithium ion too.

[Bowie69]

Yup, a LR with the same range as a stock 200tdi would be probably getting on for 3 tons empty.

[Ed Poore]

Well one Google result suggested 27x denser so if we said 85kg for 100l(ish) of fuel then that would need to be about 2.3t in batteries alone.

[Bowie69]

100l tank in what?

[Ed Poore]

Well okay an 85l tank if you want a standard 110 one.

[Bowie69]

I could see the EV drive train being 2t, for sure -and it would drive horribly.

[Happyoldgit]

Great thread chaps🙂