Electric Defender on Fifth Gear

[solmanic]

The latest episode of Fifth Gear in the UK has a story on the prototype electric Defender. The episode is sure to come up on Youtube soon as all other episodes in the current series appear to be there for viewing.

Not a huge amout of info but some nice shots of the Solihull Land Rover Experience track. Only 100km range off a single charge so it's a fair way off being viable... unless they could come up with an effective solar fast-charger, then we would be set here in Aus. Instant 100% application of torque and no need for any gears are nice features though. Also 800mm wading depth due to no air intake which is deeper than a standard Deefer.

There is also an interesting 2nd hand comparison story later in the episode. A beat-up old Defender vs 1990s era G-Wagen vs Hummer H2?!?

http://i256.photobucket.com/albums/hh191/solmanic42/ElectricDeefer.jpg (http://s256.photobucket.com/user/solmanic42/media/ElectricDeefer.jpg.html)

[460cixy]

There's something about that show I just can't watch it

[loanrangie]

You have to wonder why when a diesel defender will probably get better range/ economy and then when you take into account the cost of the batteries and then recharge costs still come out in front with diesel.

[solmanic]

There's something about that show I just can't watch it

I think you need to keep reminding yourself that it's not Top Gear.


You have to wonder why when a diesel defender will probably get better range/ economy and then when you take into account the cost of the batteries and then recharge costs still come out in front with diesel.

And why are they prototyping using a current model Defender as a platform when it's due to be killed off?

[460cixy]

I think you need to keep reminding yourself that it's not Top Gear.

I know I keep expecting it to be awesome then walk away disappointed

And why are they prototyping using a current model Defender as a platform when it's due to be killed off?

I recon the whole thing is a bit of a wast. But it most likely makes a good test bed all the same

[isuzutoo-eh]

Isn't the hole on the back of the LT230 ripe for fitting a traction motor?

[shorty943]

Electric! Wading depth = going into water!

It's a Land Rover for the Good Lord Harry's sake.

What dill thought this was a good idea?

[solmanic]

Electric! Wading depth = going into water!

It's a Land Rover for the Good Lord Harry's sake.

What dill thought this was a good idea?

Yeah, but I heard it has an upgraded Lucas smoke installation.

[PAT303]

Actually JLR are up there as world leaders on this,they have a technical partnership with the Willians F1 team,they have made a prototype Jaguar with a turbo 4 cylinder petrol engine that hits 10500 rpm mated to two axial thrust traction motors,they produce almost 200bhp but only wieght 30kgs each and the whole lot sits in a carbon fibre tub with an alloy body to keep the rain out.If you do some searching JLR are into some very cool stuff,their new engine plant will produce engines that Williams helped develope and this defender is nothing more than a test mule,it's nothing more and they used it because they have heaps of room.I would love to see a defender with traction motors on each corner with a small lean TD under the bonnet,a third of the wieght and half the parts and four wheels able to work independant of each other,it would be a cool weapon. Pat

[isuzutoo-eh]

All that tech that posters above talk about is cool, but having each wheel with an independent traction motor is a great way to lose traction. Hence diff locks have become prevalent... Only way to overcome that is to have 100HP or so motors on each corner, and there goes your power reserve....

[MBZ460]

All that tech that posters above talk about is cool, but having each wheel with an independent traction motor is a great way to lose traction. Hence diff locks have become prevalent... Only way to overcome that is to have 100HP or so motors on each corner, and there goes your power reserve....

Really? I thought have an independently controlled motor at each wheel would allow for a awesome traction control system, not based on wheel braking but by power delivery. Also potentially better clearance since no cross axle. Great redundancy too, if one motor breaks down you still have others. And if you are in a remote location and run out of energy then you may be stranded for a few days while you charge the batteries (solar/wind) but you still dont have to ship in fuel. Remote touring may be a lot slower but not impossible and how good would it be to be energy independent?

There is a lot to like about electric drive, we just need orders-of-magnitude improvements in energy storage and solar generation (current PV is still around 14%) Imagine rolloing out a big tarp at camp, which is also a flexible 90% PV panel, filling up for the next destination. Not implausable in the future, but big oil wont like it.

[roverrescue]

100km between charges
that would suit me for a town car just fine, would only charge it once a week or so.

If it didnt cost 6 kazillion deniros I would buy one in a heartbeat!!!!
But it would have to be a soft top 90 ;)

I have a dream on the longgggg list of jobs to one day "steal" a SWB from 'uncle dick' who has a fair old collection on his property. Gut it of its engine and plonk in a juicy 3ph motor... battery bank in the tray under a false floor and very simple control systems... Just for a town car! Just because it would so nice doing a wharfie in silence with everyone thinking the old landy was dead and just rolling along the street!

Bring it on I say - oh and I spose if we all start driving electric we might need to build a handful of thorium reactors to juice them ;)

S

[isuzutoo-eh]

Really? I thought have an independently controlled motor at each wheel would allow for a awesome traction control system, not based on wheel braking but by power delivery. Also potentially better clearance since no cross axle.

Imagine a rutted hill climb chewed up by bogans in wannabe comp buggies, your Landy keeps lifting wheels as it runs out of articulation. The climb is steep and load is heavy, it requires 300nM of torque applied to the ground to maintain progress.
An engine in a Defender generating say 400nM, in our perfect world, transmits that 400nM to the transfer case. Torque naturally goes to the easiest release. If the centre diff is open, the torque goes to the wheel with least resistance, such as a wheel in the air. Lift a wheel, stop. Lock the centre diff and the 400nM is available to both front and rear all the time, lift one wheel, 300nM still gets to the ground. Lift wheels at opposite ends, all 400nM is dissipated into wheel spin.
Add cross axle diff locks, and all four wheels have all 400nM available to maintain traction, 400nM is greater than the 300nM required, so driver reaches the top with a smile and wave.
Now go electric, we still have a total of 400nM available, but that is spread over four independent motors, 100nM per corner. Lift one wheel, well well we're on the verge of failing to proceed, 300nM gets to the ground but we need every last nM now. Lift two wheels, uh oh we've only got 200nM when we need 300nM. Failed to proceed.
Without a mechanical link between hubs, electric motors will need (near enough) to be as powerful as the engine they replace.

Even having two motors, axle mounted, will only be as good as a D2 without centre diff lock but with traction control, ie, mediocre.

Now if battery energy density was far far greater it'd be quite reasonable to have each traction motor to produce that 400nM, but that won't be likely for a while yet. And then you'd have issues with all four breaking traction easily and sitting there spinning...traction control doesn't register ground speed only wheel speed!

So stick your big electric motor on the transfer case and distribute the power mechanically.

[PAT303]

You could go either way,JLR have a petrol engine providing power plus two traction motors,one front one rear,you could have one each corner,at 25kgs each and providing 150kw each they could all work indedendant of one another and give 150kw per wheel,the only limiting factor would be tyre grip,no diff's/axles,gearbox,TC,clutch etc etc.If I had the money and time I would do what roverrescue posted and build one. Pat

[Duke4]

There was an American show I saw on Foxtel about a year ago where they were testing electric cars against petrol.
On one episode they had a guy who converted his series landrover to electric so they put this up against a V8 Disco 2 (I think).
They went through a series of head to head tests which in typical yank fashion didn't prove anything, for example one was against wheel travel, you know where you drive one wheel up a ramp to see how far you get before loosing traction. Yes that tells you alot about petrol Vs electric.
The electric series did go quite well up a steep climb, I think in the end they gave the win to the V8 Disco.

[solmanic]

...Lift two wheels, uh oh we've only got 200nM when we need 300nM. Failed to proceed.
Without a mechanical link between hubs, electric motors will need (near enough) to be as powerful as the engine they replace.

Even having two motors, axle mounted, will only be as good as a D2 without centre diff lock but with traction control, ie, mediocre.

Now if battery energy density was far far greater it'd be quite reasonable to have each traction motor to produce that 400nM, but that won't be likely for a while yet. And then you'd have issues with all four breaking traction easily and sitting there spinning...traction control doesn't register ground speed only wheel speed!

So stick your big electric motor on the transfer case and distribute the power mechanically.

But surely there is still the advantage that whatever torque you do have is available instantly. So with say one wheel up in the air, you still have an instant 300Nm available.

Most high speed trains use the motor on every wheel principle.

[isuzutoo-eh]

Most high speed trains don't lift wheels off the rail either, so all motors are providing effort all the time and near enough equally.
Aren't they axle hung traction motors, not wheel hung? All the Aussie electric or diesel electrics use axle hung traction motors. And despite having a mere couple of centimetres wheel articulation, they keep their wheels on the rails pretty consistently. No comparison to an off road vehicle.

Yes the way electric motors produce torque is very different to internal combustion, so you get it from zero rpm to everything, a great advantage. But each independent electric motor has to be powerful/torquey enough to do the full job of its contemporary internal combustion engine if the 4WD E-Landy is meant to be as capable as a triple diff locked IC Landy.

The D3/D4 etc wouldn't have the option of a rear diff lock if independently powered wheels were more capable.

Hmmm with wheel mount electric motors, could almost turn a 90 into a skid steer! Better than fiddle brakes!

[Didge]

Mark, you're losing me slightly with your description of torque distribution. I thought that if the centre diff lock was engaged and in the case of a 300TDi you're getting 300Nm (I know its got nothing to do with the engine nomenclature) then you're basically getting 150Nm to the front diff and the same to the rear diff. Then if you lift any wheel anywhere you've lost 150Nm and are relying on the remaining 150Nm with traction to get you out of a whole.
I've always thought a very small diesel motor with alternators providing constant power to 4 independent electric motors at each wheel would be a solution. No need for big battery storage, the diesel is only idling most of the time so driving range is increased dramatically and electric motors have fantastic torque so with four of them (obviously there is a need for some dreaded computer and electronic control) you shouldn't get stuck. I just looked up and found the first search result as a 27kg continuous 400Nm torque (max 800Nm) elect motor. Problem may be providing 75kW of power to each motor. Doesn't sound that hard to me. :)

[isuzutoo-eh]

Gerald, if the diff is locked, it can't be different from one end to the other. Speed can't vary end to end either.
The physics bumph: Energy is neither created nor destroyed, just transformed. Torque is force times the distance (aka length of the lever/stroke of the engine etc). Force is effectively the energy applied against that lever.

Imagine you hold vertically a lump of 2x4 near the middle and try and spin it with the strength of the very scientific '1 clockwise torque'. Your mate Peter is holding the top trying to stop you turning it. The other end is free. He has to apply equal and opposite force, 1 anticlockwise torque to what you apply to stop it turning.

Then he changes end. He still has to apply 1 anticlockwise torque to the bottom to stop you spinning it, because you are still applying 1 clockwise torque and the top is doing nothing.

Third time, he grabs with one hand on each end-the sum of the force he puts in at each end still has to equal 1 anticlockwise torque to stop your 1 clockwise torque to stop it turning, but he can spread it over two ends. The sum of both ends still equals 1 anticlockwise torque. But if his left hand is weak, the sum of his efforts still has to equal 1 anticlockwise torque, so his right hand has to put in more effort. Say he suddenly lets go with one hand, the one still holding on still has to apply a total of 1 anticlockwise torque to prevent you winning.

Just because one end isn't feeling strong (wheels in the air or on slippery mud) the other end doesn't get half hearted or there'd be a whole lot of torque escaping, and as energy is neither created nor destroyed, it'd be transformed into something like noise, heat, or buckling metal...

An ATB/trutrac/quaife geared LSD however does have a torque split, be it 50:50 or 70:30 or what have you, because the ends aren't mechanically locked together as such.
Hope that all makes sense...

[Pedro_The_Swift]

just wacking an"electric motor' on each wheel sounds simple--
A bit of light reading,,,

The Electric Motor (http://www.edisontechcenter.org/electricmotors.html)

The Electric Motor2 (http://www.edisontechcenter.org/electricmotors.html)

[101 Ron]

Everyone one has missed a point.
I work on and sell electric forklifts...........they have been around since the 1920s.
Cutting edge stuff we are now getting on cars like electric motor power steering has been in use on forklifts for more than 30 years.
( transitor chopping speed controllers, AC drive motors and a lot of other stuff used in forklifts long before electric cars.)
I can sell a Internal combustion forklift for 20k, but the same sort of forklift in a electric model will cost over 40k.
High purchase price and poor resale values too.
Battery replacement will set you back more than 5 k every ten years.
The fact is the price of copper and other assorted metals cost a lot more than steel.
It is also interesting to note many years ago iron/air batteries were advailable, they were notable in the fact they could be washed out and new chemicals added and the battery would be good for another Ten years.
The iron batteries fell to the wayside as the battery people and others were not making money with them.
The way to do it is a single traction motor on the transfercase and still having high and low range.
A very small diesel running at constant speed (constand speed will give a near 50% efficiency fuel burn) of say 18 BHP driving a generator is enough to allow good range extension and emergency top up of the battery over time.
You would have most of the advantages of a pure electric like regen braking and low pollution.
It will be the way of the future if costs can be reduced (not likely)
I think the Toyota /prirus General motors/ Volta hybrid is a dead end.
Money makes the world go round and is something the greens need to understand abit...................most people are of limited means money wise.

[UncleHo]

To add to what Ron said,Diesel-Electric Locomotives have been around for a lot of years,and if they weren't cost effective they would not still be in use,and they can haul quite heavy loads.

[101 Ron]

Here is something of interest.
it is old hat now being Lead acid batteries.
These are pictures of a Enfield electric car I used to own.
I ended up fitting new batteries and doing a few mods to sort things out and then played with it.
It was sold to QLD and I think it ended up in Giltraps Museam not long before it closed down.
it had a compound wound motor with direct drive to the diff.
It was a steel space frame tube chassis with all alloy panels.
Speed control was by voltage switching and series/parallel switching of the motor using Albright contactors.
Built in battery charger.
In one of the pics you should be able to see a house hold 240 volt power meter( behind the front seat in the back) so you know exactly how much the thing costs to run.
I had a large volt meter to tell you the state of the batteries.
It could spin the drive tyres on hard standing start acceleration.
It went OK on the flat, but died very badly on any reasonable hill due to the weight of the batteries.
These days why electric vehicles are now a possible option is not so much about the energy density of modern ....say lithium batteries ,but the reduced weight compared to old lead acid.
https://www.aulro.com/afvb/images/imported/2013/11/1587.jpg (http://s131.photobucket.com/user/101Ron/media/ron%203/Scan0026_zps109dc133.jpg.html)
https://www.aulro.com/afvb/images/imported/2013/11/1588.jpg (http://s131.photobucket.com/user/101Ron/media/ron%203/Scan0034_zpsec40da4c.jpg.html)

[101 Ron]

https://www.aulro.com/afvb/images/imported/2013/11/1584.jpg (http://s131.photobucket.com/user/101Ron/media/ron%203/Scan0033_zps7e91f013.jpg.html)
https://www.aulro.com/afvb/images/imported/2013/11/1585.jpg (http://s131.photobucket.com/user/101Ron/media/ron%203/Scan0027_zps7499d512.jpg.html)
https://www.aulro.com/afvb/images/imported/2013/11/1586.jpg (http://s131.photobucket.com/user/101Ron/media/ron%203/Scan0030_zps1b504571.jpg.html)

[101 Ron]

https://www.aulro.com/afvb/images/imported/2013/11/1580.jpg (http://s131.photobucket.com/user/101Ron/media/ron%203/Scan0031_zpsbe9ec894.jpg.html)
https://www.aulro.com/afvb/images/imported/2013/11/1581.jpg (http://s131.photobucket.com/user/101Ron/media/ron%203/Scan0032_zps2489e2f1.jpg.html)
https://www.aulro.com/afvb/images/imported/2013/11/1582.jpg (http://s131.photobucket.com/user/101Ron/media/ron%203/Scan0028_zpsd585143c.jpg.html)
https://www.aulro.com/afvb/images/imported/2013/11/1583.jpg (http://s131.photobucket.com/user/101Ron/media/ron%203/Scan0029_zpscd6b3187.jpg.html)

[101 Ron]

I did a google and found this.
Old Top Gear Enfield 8000 - YouTube
Interestingly my Enfield was one of two imported and used by the Victorian electricity commission.
I could get over 48 mph on mine.
I never had google when I owned it and have learnt more about it now in the last 20 mins.
Enfield 8000 - Wikipedia, the free encyclopedia
I was a fun piece of kit and got some weird looks.

[benji]

To further add fuel to the fire, say a 2.4puma puts out 400nm, and the crawl ratio is is 70:1, thats way more than 400nm; and if its triple locked that puts that whole amount of torque at any wheel (it's not always usable though).

Haven't volvo made a diesel electric? It was something like a 3cyl 800cc tuned to beyond belief for a fixed rev and torque load and achieved something stupid like 1.7 ish l/100km. I'll try to look it up.

Yes a motor where the gearbox is, coupled to the transfer case, and the smallest of the puma motor series running as a stationary engine.

Unless it's indepenant you'd have to consider unsprung weight too.

Sent from my GT-I9305T using AULRO mobile app

[Didge]

I hear what you're all saying and thanks Mark :), I do understand moments and torque quite well ( I teach it at TAFE from time to time) and thanks Pedro for smashing me with that electric motor link :),
however here is what I was thinking would be possible and I don't understand why it wouldn't be but am happy to be corrected.
Very small diesel spinning a set of generators/ alternators that will power an electric motor at each wheel. They are all independent of each other but could incorporate clutches to allow slippage and electronic speed controllers to each motor to facilitate traction on the dirt and cornering on the tar. Lifting a wheel wouldn't cause all torque to go to that wheel because it is independent of the others. Obviously it would need to be computer controlled but when you can buy flight controllers for quadcopters for $65 that control 4 motors I'm sure a car company could come up with one for a car to control four separate motors as desired. Standard battery set up to start the diesel.
Get rid of axles, diffs, gearbox and transfer case - what does all that weigh? So, where am I going wrong?
I need to know before we start this new car company, raise some capital,smash the Japs and retire in a year or two as squillionaires :P

[DiscoMick]

Is there a reason why they haven't covered the roof of that Defender with solar panels to extend its range beyond 100km? Just asking...

[Didge]

It'll get scratched in the bush?

[jonesy63]

Nah - it's England... not enough sun to charge it! :wasntme:

[MBZ460]

Is there a reason why they haven't covered the roof of that Defender with solar panels to extend its range beyond 100km? Just asking...

You would have to park it in the sun for weeks (months?) to generate enough energy to get anywhere. Solar covering a roof would be enough to run a car fridge, thats about it.

However, a big RTG (http://en.m.wikipedia.org/wiki/Radioisotope_thermoelectric_generator) would be handy, 30 years before a refill?