[foureva]

Hi,
I am an electronics Engineer and am interested in building an EV with two or four wheel drive.
I am a long time rev head and have even developed two of my own engine management systems. Unfortunatley the gas guzzling type. Now I would like to build an EV with the same horsepower but burning no fuel (at least not in the car anyway).
As I'm new to EV's I'll being asking a lot of questions, and most likely more technical ones later, so don't be afraid to give an in depth reply if you can.
I have a current vehcile which weighs about 1000 Kg and produces about 200Kw of power. I would to either convert another vehicle, or the exisiting one, depending on suitability, to obtain rouughly the same performance. Sounds like a tall order, but I believe it is techincally possible.
I would like to use direct drive as this would reduce a lot of the weight and I prefer to have four or rear wheel drive as apposed to my currect front wheel drive.
Also I travel to China anually and I would like to look over there for parts like motors and particurlay lithium ion batteries. I know many after market fit outs use lead acid, but if anyone has used li-ion I would like to hear from them.

Well I could rant on for hours asking questions, but perhaps I should wait until I get a few reponses pointing me in the right direction.

[houseoffubar]

Foreva, Hello, I am new here myself, and would not have replied to your post, prefering to "leave it to the experts". However, I noticed your questions have thus far gone unanswered. I am no "expert" but, i will try to help.
The goal of building an Ev with comparable performance to a Guzzler is the holy grail of the Ev world. Things are improving, but painfully slowly.
The fact that you are thinking Lithium is a huge jump in having acceptable performance outcomes. I have not used lithium for any projects as of yet, and therefor have no personal recommendations. I have heard of people using Thunder sky Lithium batteries (China) http://www.thunder-sky.com/index.asp I have heard both good reviews, and bad, so your on your own. You could also look into A123. I believe these will be significantly more money, but expect better results also.
As for direct drive to 1, 2, or four wheels. You should have no problem, as many high performance Ev's are direct drive. http://www.acpropulsion.com/tzero/
http://www.wrightspeed.com/x1.html
http://www.teslamotors.com/

These are all AC drive systems, but with enough amps, and 1000kg or preferably less, a DC system could be used, as with the Meyers NMG or Corbin Sparrow. Several fast DC drag vehicles are direct drive, like...http://www.killacycle.com/ ,http://www.commutercars.com/or White Zombie http://www.austinev.org/evalbum/35 This is a Datsun 1200 running high eleven second quarter mile, and able to drive 25mi. on the street with lead acid batteries. This range could be significantly improved using Lithium.
Check out Austin Ev if you have not. There are a lot of interesting vehicles to get ideas from. http://www.austinev.org/evalbum/type Good luck, Eric

[david85]

PML flightlink is one of the better examples of direct drive I have ever seen, but a good compramise could be using a rear wheel drive car, with say, 4.10 differential gears, and using a DC motor in the end on a shortened driveshaft.

John Wayland's whte zombie is a good example of that type of system, and there are now DC motors available that can actually have their winding switched from parallel to series, the zilla motor controller has a similar ability by switching battery pack wiring.

Switching from series to parallel produces vurtal gearing to get you up to speed without bogging the motor and using up extra amps needlessly. (high amps with low volts means more low speed torque, where high volts and low amps gives better RPM but lower torque)

[nathan777]

Hi,
I am new to the site, however have been interested in ev for a while. I live on the Sunshine Coast and would be interested to know if you have proceeded any further with your ev.

[Mastiff]

Well I must ask the all important question which will decide the rest of your conversion:
What is your Budget for this Vehicle?

The performance you seek can be achieved easily, electric motors scale very well.

The trick is the batteries, they will define the performance of your vehicle.

A123Systems has the highest drain rate, light weight batteries available:
http://www.a123systems.com/

Other lithium battery providers are Valence:
http://www.valence.com/products/cells_home.html

LionEV (Lithium Iron Phosphate (LiFePO4) cells from China):
http://www.lionev.com/


As for motors and controllers:

Metric Mind sells Siemens AC Motors and controllers:
http://www.metricmind.com/index1.htm

Electro Automotive sells Azure Dynamics(AKA Solectria) AC motors and controllers:
http://www.electroauto.com/catalog/ackits.shtml#heavy

You can also goto Azure Dynamics website for very detailed info on their systems:
http://www.azuredynamics.com/productsComponents.htm

PDF specs with Torque curves and everything.


If you want a DC system:

Cafe Electric makes the most powerful DC motor controller I know of:
http://cafeelectric.com/zilla.php

Netgain Technologies makes the WarP series of DC motors:
http://www.go-ev.com/WarP.html

They've been used in drag racing before and have every size you'd want.

There's also Advanced DC motors:
http://www.adcmotors.com/

Battery Powered Systems sells the ADC motors:
http://www.beepscom.com/category_s/41.htm

I haven't seen these used in any racing vehicles though.


The performance is available, unfortunately it all comes down to my first question:
What is your budget?

[lajollan]

Originally Posted by Mastiff

Well I must ask the all important question which will decide the rest of your conversion:
What is your Budget for this Vehicle?

The performance you seek can be achieved easily, electric motors scale very well.

As for motors and controllers:

Metric Mind sells Siemens AC Motors and controllers:
http://www.metricmind.com/index1.htm

Electro Automotive sells Azure Dynamics(AKA Solectria) AC motors and controllers:
http://www.electroauto.com/catalog/ackits.shtml#heavy

You can also goto Azure Dynamics website for very detailed info on their systems:
http://www.azuredynamics.com/productsComponents.htm

PDF specs with Torque curves and everything.
I haven't seen these used in any racing vehicles though.


The performance is available, unfortunately it all comes down to my first question:
What is your budget?

I am a new poster to this site, but have been doing quite a bit of research over the last 2 years. I have not found a lot of information on what I would consider high performance EV's.

I have a donor Audi TT Coupe that I would like to make direct drive to each wheel, 4 or 8 motors, with 800+ effective total HP. I assume this will be expensive, using the latest Lithium batteries and probably will need a custom controller to minimize wheel spin.

Not worried about range, just broken records and publicity.

I'm a Mechanical Engeneering student and can get the school to turn this into a project and will be looking for sponsorship from battery, motor and controller companies.

I'm guessing $250k plus the car, but I cannot find anyone that can supply motors or controllers in the Tesla power range.

Any ideas?

[foureva]

Hi.
It seems I mispoke bit in my description. Actually when I said direct drive I was referring to hub drive motors ala mini qed.
There as some motor designs around that I belive I could scale to my requirements.
What I don't know is if there are any controllers for this type of motor available or if I need to nake my own.
I have been out of the loop for a while on this due to family stuff so I may be a bit out of date in regards to batteries.
I looked at LiFe type before an energy densities were half that of straight Lion , making them a very course soluiton in an EV. ( Better than Lead acid no doubt, but still). I haven't compared the LiFe MgPO4 to Lion so if you could save me some hassle there and tell how they compare in power/weight with Lion that would be nice. I assume a lot of these Lion variants are made to avoid the complicated charging of Lion, but untill they match or come close to Lion Power/weight then they just make things harder. I would also consider using less batteries and a generator to charge them to avoid having to many expensive heavy batteries. In my case I may only need about 50-100km range 99% of the time so a generator backup for long distance makes more sense to me. (Don't crucify me for buring fuel 1% of the time please).
Budget, hmmm.. well It depends on how much I make myself, but I would guess about 10-15K if I build my own motors and source batteries directly from manufacturers in china. Controllers, well I would like to buy one but doubt they exist for hub drive motors.
Do any controllers also support traction control and other more advanced controlling of power for stability?
I guess one really needs to be an engineer to accomplish what I'm after, but I hoped that maybe there was another nutty engineer like me around.

Regards,
Kent.

[lajollan]

Originally Posted by foureva

Hi.
It seems I mispoke bit in my description. Actually when I said direct drive I was referring to hub drive motors ala mini qed.
There as some motor designs around that I belive I could scale to my requirements.
What I don't know is if there are any controllers for this type of motor available or if I need to nake my own.
I have been out of the loop for a while on this due to family stuff so I may be a bit out of date in regards to batteries.
I looked at LiFe type before an energy densities were half that of straight Lion , making them a very course soluiton in an EV. ( Better than Lead acid no doubt, but still). I haven't compared the LiFe MgPO4 to Lion so if you could save me some hassle there and tell how they compare in power/weight with Lion that would be nice. I assume a lot of these Lion
Budget, hmmm.. well It depends on how much I make myself, but I would guess about 10-15K if I build my own motors and source batteries directly from manufacturers in china. Controllers, well I would like to buy one but doubt they exist for hub drive motors.

Hub motors seem like an awful lot of unsprug weight and it makes manual brakes harder to accomplish.(for dead stop or quick stop) Also a TON of manufatured parts in the car, hubs, suspention, A frame, links, sway bar mounts, etc.
I gave up the DD hub wheels and decided to go with a native AWD car and connect motors to the 4 drive axles.

Thoughts?

[CroDriver]

Two dual Kostov 11"-s, two Zilla Z2ks and 50 parallel X 112 series A123 cells and you'll have over 1500hp

Weight:

2 dual motors are 320 kg

2 Zillas are 20 kg (not sure)

5600 A123 cells are 392 kg

+ 50 kg battery mounts, motor mounts and stuff like this...

Cost:

Motos: $8.000

Controllers: $20.000

Batteries: $33.600

+ $10.000 for contactors, BMS, charger...

+ $20.000 for body work, suspension and stuff like this.

You almost have to kiss the feet of some EV part part manufacturers to get their stuff. No chance of sponsorship, especially if you're without any results

Still interested?

[lajollan]

Originally Posted by CroDriver

Two dual Kostov 11"-s, two Zilla Z2ks and 50 parallel X 112 series A123 cells and you'll have over 1500hp

Weight:

2 dual motors are 320 kg

2 Zillas are 20 kg (not sure)

5600 A123 cells are 392 kg

+ 50 kg battery mounts, motor mounts and stuff like this...

Cost:

Motos: $8.000

Controllers: $20.000

Batteries: $33.600

+ $10.000 for contactors, BMS, charger...

+ $20.000 for body work, suspension and stuff like this.

You almost have to kiss the feet of some EV part part manufacturers to get their stuff. No chance of sponsorship, especially if you're without any results

Still interested?

VERY!

I'm assuming this would be a 2wd car with 2 dual motors... what about 4 dual motors? or were you assuming having a diff on the front and back.

I am thinking AWD to keep the thing on the ground during launch.

It looks like your estimate was under $100k (plus car), that's WAAAY under my estimate of $250K


If I'm gonna do this, it's going to be done right.