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Discussion Starter #1
In driving my 2.5 tdi around as a daily i have observed that it would be very much lighter on its feet if it had mucho torque on tap at startup. Exactly what an electric motor provides. Also that fuel economy when so many miles are stop start miles would benefit hugely from an electric regen system. Motorway cruising and range the diesel is great at. So basically making the vehicle more useable round town without affecting its mile munching capability.

You also dont want excess mechanical complexity - hence none of that toyota hybrid engine type lark. I dont need a motor to add power at 80mph, just for town use and pulling off, 0-20 mph.

Now ive built a number of electric bicycles and created full plans for a motorbike (which I never built as I wouldnt have need of it) so I know a little about electric vehicles. Here is my idea.

Idea 1 - rear wheels replaced with a hub motor.
Pros
simple and light
4 wheel drive when stuck
Cons
finding a hub motor that can cope with a 2.5 tonne vehicle
looks
unsprung weight


Idea 2 - Rear running gear from a syncro. Prop shafts and rear differential. Motor connected to the diff (possible with a reducing gear if required). (see here. )
Pros
Fairly simple, not too heavy
4 wheel drive when stuck
wide selection of motors available, easier to tailor speed range to suit needs. Even a cheap fork lift motor.
Robust.
Cheap
Cons
More complex than hub motors
Building gear reduction if required.
Extra weight and mechanical complexity vs hub motor.

In both cases about 48 volts worth of LiFePo4 batteries, perhaps 1kwh worth of power. Thats a few miles range (at most!) but batteries recharge off braking and alternator of course. And plugged in overnight if you like. for example see these. Note that size (340x190x114mm) and weight (8.62kg) is tiny compared to lead acid.

Batteries probably behind rear seats to be placed near the underslung motor for minimum losses over short cable run. These babies require HIGH CURRENTS.

A 8-10kw motor would provide 15 horsepower with huge torque for pulling away (much more than 15 ice horsepower would give you), and would draw 200 amps at full power.

Motor controller will feed input off the main throttle, hopefully can be wired in to the existing pickup but if not a second pickup attached to the throttle pedal. Designed so that when you lift off entirely a small amount of regen braking is turned on automatically (will feel like extra engine braking).

Brake pedal will be adjusted so initial travel only does regen braking, and further pressing engages the mechanical braking system.

To really freak people out, turn off your engine, put it in neutral, and press the gas. Away you go! :)

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Lets reiterate - town only. 0-20 or 0-30mph. Helping the ice, not replacing it. Vehicle feels lighter on acceleration, and more efficient thanks to regen. Can be plugged in for a few nearly free miles. As a bonus that much battery will run your fridge off grid for weeks!

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Start throwing stones chaps and chapesses.
 

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Good luck with this, ive done a lot of research and driven a few EV,s and Hybrids and like them a lot. There is a company in the north east called Smith electric vehicles who are part of an american company. They convert LGV,S, mini buses ,vans etc on a big scale. it might be worth googling them. They are to big for one offs.
They also used to use Zebra batteries which are interesting and much better than lead acid and much cheaper than lithium Ion.
If you go down this route please let everyone know how its going. Dave
 

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A few years ago, I was involved in sourcing an electric delivery vehicle for a company I used to work for. The benefits were no parking or congestion charges in central London, low energy costs & a green badge to show off :) If you've got any experience with this stuff, you'll realise the downsides are battery life, battery cost, recharging time and limited range.

I remember asking the question. "Why can't we run a generator in the back of the van to top up the batteries as we go along?" and it was laughed off, but it now looks like some of the hybrid designs may well go that way (I probably saw something on TV that the others hadn't. I'm sure it wasn't all my idea). Instead of using the engine to inefficiently power the gears and the wheels, the engine is run at the most efficient speed to recharge the batteries that power the motors that power the wheels, thereby getting the most from an economy point of view. Like all this stuff, the variables are unending. Good luck with your idea, I like thinking about & discussing stuff like this, it keeps the mind active, but I wouldn't want to be spending money on it just yet.

All the best,

Al.

PS Have a look at the VW X1 concept car. 300mpg and an absolute beauty of a motor. http://www.autospies.com/news/Volkswagen-s-300-MPG-X1-Caught-Undergoing-Scandinavian-Winter-Testing-74384/ A:A:A:A:A:A:A: I WANT !!!!!
 

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to get sufficient regen its common for todays hybrids to apply the combustion engine against the regen action & generate more charge, regen isnt that efficient unless you are braking from high speeds regulary. Your then into balancing braking effort against tractive force from the combustion engine whilst ensuring the driver gets the requested decel from the brake pedal..
As a minimum youll need an ABS system that can provide drivers brake line pressure data, then a way to integrate the ACV's pedal follower (non torque model) control system, engaged gear info from the gearbox.. You can then work with wheel torque data from all systems and create a control module that ensures you only get the accceleration expected from your accel pedal input or the decel from your brake input..

Regen forces are considerable..
 

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Great idea, masses of work!
I wonder if you could try and generate some power via the flywheel? is there is enough space to make a PMA?
I've seen some plans for permanent magnet alternators made using rear hub/drums for for use with VAWT Generators.

I like the idea of the synco running gear, a friend of mine once made a trailer using a landrover discovery (he chopped the front off to the bulkhead).
The rear axle still had the diff inside and spun the drive shaft flange

I'd thought of fitting a large motorcycle rear sprocket to the flange so the chain could go through the floor of the discovery to another sprocket which then geared up and connected to a high power alternator such as the lower RPM kick in high output BMW alternators.

It could charge a very large bank of forklift batteries while driving and power a large fridge(full of beer) and inverter etc

I'd thought about perhaps making it so you could drop an internal jack, so you could jack one wheel up and have the hub with connected to a wind turbine or a push bike maybe.

I saw a picture on here of a solar panel that filled the entire roof of ma T4 on here somewhere, the op reported that it made enough power to keep him topped up, this might be worth a looky.

The batteries made by A123 systems are what you need.
I have a friend in Canada with a rapid 2 seater sports car powered by them.

I will keep an eye on this thread.
Good luck and keep us updated.
SB:ILU:
 

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Really interesting idea, I always wanted to do something similar to my 106gti - back then my commute was 5miles of brilliant followed by a mile of stopstart traffic, I figured an electric motor on one of the rear wheels would be the perfect solution for the traffic. Couldnt comment on the technology, but really interested to see how this project progresses.
 

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Discussion Starter #9
I imagined that the battery when low would be topped up by the alternator. A bms would be required to protect it from over discharge, and overcharge conditions. Voltage measurement would suffice to choose a voltage at which to start topping up. I won't try and charge the battery by balancing engine power against regen, it's too complex and possibly less efficient as well. That way the throttle is purely controlling motor boost, more throttle gives more fuel to the engine and more current to the motor at the same time. Zero throttle is mild regen braking.



to get sufficient regen its common for todays hybrids to apply the combustion engine against the regen action & generate more charge, regen isnt that efficient unless you are braking from high speeds regulary. Your then into balancing braking effort against tractive force from the combustion engine whilst ensuring the driver gets the requested decel from the brake pedal..
As a minimum youll need an ABS system that can provide drivers brake line pressure data, then a way to integrate the ACV's pedal follower (non torque model) control system, engaged gear info from the gearbox.. You can then work with wheel torque data from all systems and create a control module that ensures you only get the accceleration expected from your accel pedal input or the decel from your brake input..

Regen forces are considerable..
 

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Discussion Starter #10
A123 batteries! They are capable of such high power delivery, but come in such small capacity that they are a bugger to work with. I stopped using them even on a bicycle. Need a lot of wiring and a lot of battery management to provide a kwh at 50 volts. Usually they come in 2.3ah 3.3 volt cells. Need about 130 cells! Expensive too. Great for a high powered sports car though.

I wish I could say its a project I will begin but realistically it's unlikely. I already have too much on my plate. For now it's a mental exercise and pipe dream. That said if I find myself with spare time In future i would probably do it. Start with a second hand forklift motor, second hand lead acid batteries, and a syncro diff should not cost too much. Probably the diff would be the most (no idea though). Most expensive bit is the controller/contacter at maybe £300. Not too bad cost wise to see if its feasible.
 

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Discussion Starter #11
Yeah the vauxhall ampere has gone that route. Sexy styling too. I can only assume that it was more costly at first to have motors and battery powerful enough to be doing all the driving, and a small generator to recharge for range. Otherwise why the huge complexity if the Prius type design.

I remember asking the question. "Why can't we run a generator in the back of the van to top up the batteries as we go along?" and it was laughed off, but it now looks like some of the hybrid designs may well go that way
 

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If money were not option I would machine my own flywheel with large Neodymium Magnets and have the windings inside the bell housing so even on idle it would generating power, no need for an external alternator anymore. It would be AC but soon make a rectifier
After the batteries were topped up you could either uncouple the coils or dump the extra power into heating? sound system? light?

I think someone locally here tried it with a forklift motor in mk1 passat estate, I think he struggled to get any range for the amount of batteries he had to carry.

Milk float motors and gearbox?
I think you'd have to lighten the T4 immensely, no spare etc.


Interesting concept, makes me actually use my brain! LOL:

Someone here might pop up that has all ready tried it, you never know.
SB

*EDIT*
With a large back of 2v batteries like item number 230928661454 would get you your short distance and low speed.
 

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Discussion Starter #13 (Edited)
Magnets in the bellhousing...

I love that idea, but would add a fair bit of extra work to the conversion.

Yes range isnt something this idea is aimed at. Power, and a touch more mpg, and a 'poor mans' 4wd. Although I suspect the batteries would provide only a few miles range, for a school run of less than 10 miles a day of town driving it would help a fair bit.

I dont think weight is going to be such an isssue though.

forklift motor (heavy duty) - 100kg OR 10-20kw EV vehicle motor (from http://www.goldenmotor.com/) 17kg
rear diff off a syncro ??
battery (link in my first post) 10kg

Total extra weight is probably less than the weight of a full syncro t4..

Cost is another issue (in dollars as thats what most of this is priced in)
battery $800
EV vehicle motor (not forklift) $800
Diff (no idea, lets guess £200)
controller ($400)
Other bits (probably another $3-400)

So total cost $2400 + £200, roughly £1700.
 

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Hi there
Have you gotten any further on your quest?
Any interesting parts or concepts arrived or is it still floating about on paper?

I had a thought the other day, more about PMAs, I was thinking you could install magnets on the inside of an alloy wheel, you could have the windings mounted on the outside of the hub, aligned with the magnets.
Its not megavolts, but it is energy.

Here are some interesting concepts on the same theory.
http://www.radiolocman.com/shem/schematics.html?di=45613 <-Hamster-Powered Night Light With Custom Low-RPM Alternator

From here http://otherpower.com/otherpower_wind_alternators.html


This idea of using rear stub axles that already are perfect with a little tinkering got me into making my own wind turbines to charge small SLABs a few years back. This isn't to far from the bell housing PMA idea.

Any updates?
SB
 

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Discussion Starter #15
At best it will be a long term quest around other things. Money and time both being tight these days.

I like the idea of converting a wheel, but I would want the end result to be reliable and easy to maintain. Common parts as much as possible rather than too much custom work. Off the shelf motors, controllers etc.
 

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the idea of using the flywheel which other earlier posters have mentioned sounds good to me.

potentially replace the starter motor (and alternator!?) with something a bit more suited to the job - which could save weight over two hub motors.

Not really thought through all the pros and cons, it just seemed simpler from an engineering perspective and potentially cheaper as you are minimising hardware?

could you drive the van via motor with the ICE switched off - not sure?
could you start the ICE using the motor - very likely
would it be of benefit to charge whilst stationary in traffic - yep

an interesting problem whichever way you go, best of luck and keep us informed if you progress! Not enough of this private development work goes on in my eyes! Some of th ebest inventions come from 'Fred in a shed' T:
 

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Is the generator/motor in the bellhousing similar in pricipal to Hondas IMA system. Also isnt it the case that if you put a generator onto an ICE isnt it then going to use more fuel at idle than it would normally do.
 

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I can well imagine that if VW do produce an electric retro transporter it would not be long before some bright spark sets up a beetle engine on a trailer driving a generator that would charge the batteries. fully blinged beetle engine could be quite a work of art.
 

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I love this idea. Original concept seems simple enough. I did see a G wizz for sale for £800. Possibly the cheapest wat to get all the components you need in one go ? Having changed wheel bearings it seems the front and rears are the same at least on post 96 models. So I did wonder about just sticking a driven hub in one rear wheel and just driving that direct from the motor. Ok so you're only 3 wheel drive, but no need for a diff and another drive shaft. Useful as the original post said for just pulling away and maybe around town.

For an even madder idea I did wonder about clockwork drive. Again just to pull away with, wind up using something like an air con electric clutch engaged when braking. Not exactly sure how best to engage the power...possibly the same electro clutch. I did a quick search but found no large clockwork drives !!
 
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