wtmusic's Electric Car Project / Chapter 1

[wtmusic]

This morning I bought this '97 Ford Aspire, which over the next 6 months I will be converting to 100% battery electric power.



Very excited I found the car, because in many ways it's an ideal conversion prospect:

1) Good body condition, interior, brakes, electrical, clutch
2) Not so good engine (who cares? it's getting recycled anyway)
3) Light weight (2000 lbs curb; rated at 3000 lbs gross to handle nearly five hundred pounds of battery weight).
4) Manual transmission (much better for conversions) and not a lot of extras (power windows, etc.)--saves on weight
5) Rockin' stereo and speakers (uses relatively little energy)

The goal is 75mph top speed and 90-mile range, using a 120V system (10 12-volt Optima D34 batteries). I will be posting updates as the project moves along for anyone who cares, and would love to hear from anyone who has attempted a conversion.

wtmusic got tired of waiting for Detroit.

[jilln]

1. That's really terrific.

I'll be looking forward to your updates. It's something I'd like to do in the next year or two as well.

[chaska]

2. I don't want to miss any of this. Keep us posted....

Very exciting, someone who's actually doing something.

...You know, I build guitars. Today, I've been spending time at a site that features homemade guitars by people from all over the world. It's a very interesting thing to see from a socialogical perspective. The Americans almost invariably build copies of existing iconic American guitars (Les Pauls, Strats, SGs, etc.). Guitars from other parts of the world (mainly Europe/Scandinavia) are often more elegant, but almost without exception more adventurous/innovative.

Yes, they've got us well trained (in passivity) in this country. Congratulations in breaking out of your cage.

[wtmusic]

3. Thanks, will do

I am by no means a mechanic, so it will be an adventure.

I've noticed that about guitars too. Funny thing is, you build a Strat copy and it tends to sound like a Strat. ;-)

It's hard to believe that strats/les pauls/SGs represent the pinnacle, the most expressive guitars that could ever be made. But if everyone keeps building them, that's all we'll ever have.

[NNadir]

4. This should be very interesting.

I hope you will give us all the details.

[Benhurst]

5. Looking forward to your updates. Recommended #4

[IDemo]

6. Happy to be the fifth recommend

Wish I had the garage space for a project like this!

[wtmusic]

8. Unfortunately I have none, either

My garage is my office so it's going to have to happen outside, with stuff brought in/covered up each night. Kind of a pain, but here in SoCal I'm reasonably optimistic that the weather will cooperate.

[ebayfool]

7. Rec'ced - Now THAT'S walking the talk!

So many talk @ change, how exciting that you're actually attempting to DO change! You are now on the hook ... we want details. All of 'em. Every step of the way. Pictures, plans, links - anything you can post!


Way to go!

[Javaman]

9. Start a blog with detailed photos!!!

I would love to do the very same thing!

This thread is so completely highly recommended!!

Good luck!

[piedmont]

10. I've been itching to do this for a few years now.

As soon as I'm out of grad school and have the money for the conversion, I'm going to do it. Good luck, and I can't wait to see how yours turns out.

[crispini]

11. Please start a journal

So we can all follow it along with you.

[Dead_Parrot]

12. Seconded... nt

[muriel_volestrangler]

13. My calculation may be all wrong, but ...

Is that really enough power?

The page for the D34 battery says it can provide 25A for 120 minutes, before dropping to the 10.5V recharge level. For a 90 mile range, that would be 2 hours at 45mph - so that must be the right ballpark for the power you expect to draw from them. 10 12V batteries at 25A is 10*25*12=3kW - which is 3*1.341=4 horsepower. Can you really drive a Ford Aspire at 45mph using 4 horsepower (which is assuming 100% efficiency in the electric motors)? The web says the original had a 63 bhp engine. Even if your 90 mile range is at, say, 25mph, the 55AH total charge on the battery will give you just 1.8kW - 2 horsepower. I can't believe you can keep a normal car at a steady 25mph with 2 horsepower.

[wtmusic]

14. No, your calculation is good

A little low on the battery rating -- actually 27.5A/120 minutes which adds up to 3.3KW or 4.4 HP. I'm also taking into consideration anecdotal evidence that Optima yellowtops are conservatively rated.

The range goal is admittedly...optimistic. But I can give up a lot of that range and still have a viable around-town car, so I won't be overly disappointed if it doesn't happen. I'm going to be pulling a lot of weight out of the car, investing in low-friction tires, etc. and truth is, it's a tiny, well-streamlined car. I may even go up to 144V depending on how much room is up front after I pull the engine.

[wtmusic]

22. After reading your post

and checking back through my notes I wondered if I hadn't missed something critical, and would end up being underpowered...then I stumbled across this page with a nifty range/top speed calculator:

http://www.geocities.com/CapeCanaveral/Lab/8679/evcalc.html

and according to it I'm not far off. When I plug my numbers in I get a range of 90m (at 50mph!), with a 25mph cruise eating up just under 2HP (it also gives a top speed of 100mph, which just seems whacked). But I think I'm in the ballpark.

Horsepower readings are somewhat deceptive, in that IC engines are measured at peak horsepower unloaded, whereas electric motors are rated under a continuous load.

[Kolesar]

23. An electricified bicycle uses ~250W at 20-25 mph, that is 1/3 horsepower

At which speed, most of the workload is air resistance.
All of which I am recalling from someone's citation on another message board.

[zeemike]

15. Good for you for trying

And I bet you learn a lot from tis project.
My ideal electric car would be to have motors built into the wheels themselves to eliminate all the drive train, but that may be hard to do with off the shelf parts. That is how very large dump trucks solve the problems of a drive train but to scale it down to an car size might mean you would have to manufacture the wheel motors yourself, which would be hard for the average person to do.
Good luck and keep us posted please.

[petgoat]

16. I believe Ferdinand Porsche built trucks with electric motors in

the wheels during WWI for the German Army, and they went
over the Alps.

The problem with the idea is, apparently, "unsprung weight" which
is supposed to be bad for handling. Reducing unspring weight is
why some sporty cars put the brake rotors and calipers inboard on
the transmission end of the driveshafts.

I like the idea of separate motors for the different wheels (and
eliminating the need for a differential) but I think I'd use
chain drive to keep the motor on the sprung side of the system.

[zeemike]

17. Interesting

I had not heard of that as a problem before
But handling for a dump truck the size of a house would not be a problem.
But I did hear that the army is experimenting with a 4wd electric vehicle because of the obvious advantage of silent running.
I am looking forward to seeing how you make out.

[IDemo]

18. Here's a cool wheel-motored EV

Albeit a bit overpowered at 640 hp!

A British engineering firm has put together a high-performance hybrid version of BMW's Mini Cooper. The PML Mini QED has a top speed of 150 mph, a 0-60 mph time of 4.5 seconds. The car uses a small gasoline engine with four 160 horsepower electric motors — one on each wheel. The car has been designed to run for four hours of combined urban/extra urban driving, powered only by a battery and bank of ultra capacitors. The QED supports an all-electric range of 200-250 miles and has a total range of about 932 miles (1,500 km). For longer journeys at higher speeds, a small conventional internal combustion engine (ICE) is used to re-charge the battery. In this hybrid mode, fuel economies of up to 80mpg can be achieved.

Edit - maybe not an EV in the strictest sense, more like the Chevy Volt concept car with its on board IC generator...

[wtmusic]

19. Very cool

If their claims are real, this buries the Chevy Volt.

With safe Lithium-Ion battery technology now available, it looks like the new "hybrid" will be Li-Ion/ultracapacitors -- the caps kick in for performance, the batteries provide the range.

And may oil remain where it belongs -- deep in the earth.

[papau]

20. I agree - Very cool - - A Volt with motors in the wheels! But no where is "cost"

Over my pay grade are the questions - are the statements below true and if so what does it mean, and the question of a mini at 1500 lbs vs your 2000 lbs means what to performance?


The small ICE weighs a mere 15kg (less than 1/10th of the original Mini One engine) and delivers peak power of 20kW and continuous power of 15kW. A high efficiency electrical generator is fitted to the engine to provide power when the battery depletion level demands. The key point is that the engine is run at a continuous speed and load – which results in optimum efficiency fuel conversion. After delivering the energy to the battery system the mileage equivalent translates to between 65 and 80mpg!


The Hi Pa drive system used in the Mini gives each wheel 120kW of power and therefore a total vehicle power of 480kW. The greatest technology breakthrough is with the invertor drive which is housed inside the motor and has a mass less the 2kg. NOTE: A full 120kW invertor drive with a mass of less than 2kg. This represents at least 10 times the power to mass ratio of any currently existing 120kW invertor in the world today.

[muriel_volestrangler]

21. No mechanical brakes?

I'd like to know that the electrical braking system is (a) just as effective as a mechanical one (b) as reliable as a mechanical one.

[Dead_Parrot]

24. They can be...

Using it for road transport is fairly new, but trains have used magnetic braking for some time because it's more reliable and effective than mechanical braking - no heat build up, no parts to wear, not afffected by water or oil... Hooking up wires so it runs as a generator as well is just a bonus.

I suspect the car manufacturers don't like it because you're not forking out for a new set of pads every 6 months at $50 a wheel. Or maybe I'm just being uncharitable. :)

[eppur_se_muova]

25. Interesting, didn't know those were used in trains already.

http://en.wikipedia.org/wiki/Dynamic_braking

http://en.wikipedia.org/wiki/Electromagnetic_brake

http://en.wikipedia.org/wiki/Regenerative_braking