So I got a brilliant idea and figured nothing better than ask a bunch of GS'er's on how to do it.
There are two streams of thought
1. Pure electric car:
- Frame & Body and other stuff of an old donor car - Manual tranny
- Advanced DC or AC motor
- Lithium Ion or LiPo batteries (this is the most expensive part)
- Charge controllers / Controllers
2. Pure electric car + small engine to generate enough energy (like the volt)
- Problem is that you have to deal with laws of thermodynamics here, but its doable, a small diesel or gas engine running a generator / powers the batteries. (rescue mode).
- rest as above
I have been researching and its doable. I was thinking something like a 60's VW Bug, take out the engine, put an DC / AC motor in its place, use the same transmission.
Put the batteries up front, weight calculations for a 72V DC system comes to about 150lbs for LiPo system. By calculations it should run 60mph for 60 miles easily.
The reason I was goign to use LiPo or Li-ion is because its lighter and have higher storage charge (Ah).
So what do you guys think.. lets get this discussion going. I think its super doable.
i have a little experience with electric vehicles.
check out the a123 LiFePo cells (from dewalt nano phosphate batteries). i've also sen guys use Li-poly cells from the rc world.
you'll need:
batteries
batt controller
motor
motor controller
human interface (throttle)
battery monitor
Good idea, except dont kill a bug. Well ... selfish reason aside - you want lightest car you can get with enough frame strength to carry the batteries. VW floor pans dont cut it. It doesn't have a good proper frame.
You may be best off using an old K car. Like an early 90's dodge shadow etc.
Cool.
Buddha.
If you are building one to use as a daily driver, don't use the Shadow/Spirit cars...they are quite heavy for their size...use an old econobox that no one likes (can pick up super cheap...have seen ads for cars to just pick them up to get them out of the driveway...Chevy Chevette, Geo Metro, Ford Festiva, Dodge Omni/Horizon, etc). There are some youtube vids of guys that have made quarter mile cars that are all electric...one I saw was a Datsun 510 converted, and he totally SMOKED a Viper...and I mean SMOKED :icon_twisted:...beat him by 10 car lengths...
But if you set your ramp speed (max accelleration) low, you will get more distance out of the charge. Lots of guys use the motors out of electric fork lifts to convert cars, along with the controllers etc from the fork lift. It would be a cool project and can be very reliable.
Good luck!!
Later.
Right, I am target fixated with K cars, I am driving one.
In a way you will go bi polar if you ever own one of those. In some ways its a really really great car.
Other ways its awful.
I actually overall am impressed wiht how well its held up.
Cool.
Buddha.
I had three of them over the years...1991 Shadow ES...1988 Shadow...1989 Aries K LE...don't forget the LE... :icon_mrgreen:
I liked (and still do) the looks of the Shadows, but they were heavy for such a small car (translation...slow and handling wasn't great)...the Aries was a pretty good car, if a little slow and not terribly efficient (compared to Honda's and Toyota's of the same vintage)...but he price was right and it was in pretty good shape. I bought it after I seized the engine in the '88 Shadow (my bad, I ran it out of oil...it burned a little)
Anyway, we're hijacking the post...
Later.
LeBaron convt ... I love the shadow convts too.
Yea back to electric cars ... stop hijacking the post guys.
Cool.
Buddha.
+1 to using a geo metro ... or maybe a tracker if you want a little more height ( I hate not being able to see in traffic)
My thought was always to put generators on the axel's so that the rotation charged the batteries .... especially if a good portion of your daily commute is highway, but I dunno how well that would work, but I figure if you can create enough energy with a hand crank to light a bulb a moving vehicle probably has enough to do at least some charging while at speed...
What is your budget/time frame for this project?
Quote from: Firstoni on November 09, 2010, 10:55:00 AM
+1 to using a geo metro ... or maybe a tracker if you want a little more height ( I hate not being able to see in traffic)
My thought was always to put generators on the axel's so that the rotation charged the batteries .... especially if a good portion of your daily commute is highway, but I dunno how well that would work, but I figure if you can create enough energy with a hand crank to light a bulb a moving vehicle probably has enough to do at least some charging while at speed...
if you had the generators engaged while the car was moving it would slow the vehicle down. the generators create drag on the rotation esp if you are trying to extract any useful amount of power from it.
but you are not the right track because that's how regenerative braking works. when you accelerate, the generators disengage; when you brake, the generators are engaged to charge the battery.
I'm with Buddha don't kill a Bug for selfish reasons. Though I think it would work it is definatly light enough.
I think an older Chevy Sprint would fit the bill much better, 13' wheels, front end engine, lot's of room behind the drivers seat all the way to the back!
Just a thought. :thumb:
how about a truck instead ? there are boatloads of manual tranny trucks for sale on cl... with blown engines, etc
here's why i like the truck idea better:
they're almost free if the engine is dead. they're always fully framed (heavy, but built to carry the extra load) and will ride even better with 200-300 lbs of batteries placed in the bed. hey, it's like it was MADE FOR THE CONVERSION !
the clutches on trucks are a little heavier, and your lectric motor is a torque monster, meaning start in 3rd gear and enjoy not changing at all. no clutch slippage. sweet.
you could fake-bottom the bed and pad with batteries, then still have a usable 'truck' for doing hauling/whatever. it's just what -i- would like to do.
i'm guessing you'll spend 3-4000 on your project all done and working. not really expensive when you consider a ICE car/truck will burn $30,000 dollars over it's lifetime of 200,000 miles. ouch. ( 200,000 miles / 10 mpg * $3/gallon = ouchie)
Oh yea truck ... however even blown motor trucks in good body shape sell for north of a G. Just for the reason you said, besides pull-a-part will sell motors for 2-300 bones, so it can be thrown back together ...
Cool.
Buddha.
Quote from: ohgood on November 09, 2010, 05:10:27 PM
how about a truck instead ? there are boatloads of manual tranny trucks for sale on cl... with blown engines, etc
here's why i like the truck idea better:
they're almost free if the engine is dead. they're always fully framed (heavy, but built to carry the extra load) and will ride even better with 200-300 lbs of batteries placed in the bed. hey, it's like it was MADE FOR THE CONVERSION !
the clutches on trucks are a little heavier, and your lectric motor is a torque monster, meaning start in 3rd gear and enjoy not changing at all. no clutch slippage. sweet.
you could fake-bottom the bed and pad with batteries, then still have a usable 'truck' for doing hauling/whatever. it's just what -i- would like to do.
i'm guessing you'll spend 3-4000 on your project all done and working. not really expensive when you consider a ICE car/truck will burn $30,000 dollars over it's lifetime of 200,000 miles. ouch. ( 200,000 miles / 10 mpg * $3/gallon = ouchie)
Quote from: ohgood on November 09, 2010, 05:10:27 PM
how about a truck instead ? there are boatloads of manual tranny trucks for sale on cl... with blown engines, etc
here's why i like the truck idea better:
they're almost free if the engine is dead. they're always fully framed (heavy, but built to carry the extra load) and will ride even better with 200-300 lbs of batteries placed in the bed. hey, it's like it was MADE FOR THE CONVERSION !
the clutches on trucks are a little heavier, and your lectric motor is a torque monster, meaning start in 3rd gear and enjoy not changing at all. no clutch slippage. sweet.
you could fake-bottom the bed and pad with batteries, then still have a usable 'truck' for doing hauling/whatever. it's just what -i- would like to do.
i'm guessing you'll spend 3-4000 on your project all done and working. not really expensive when you consider a ICE car/truck will burn $30,000 dollars over it's lifetime of 200,000 miles. ouch. ( 200,000 miles / 10 mpg * $3/gallon = ouchie)
Not to pick on you, but there are a couple of issues with using a truck...one you mentioned...weight...this will be the biggest problem with the electric vehicles...the more it weighs, the harder/more energy is needed to get it moving and more energy is wasted in stopping (if you use regen braking, it will help but not completely off set this) so more battery capacity is needed (more weight again)...the other problem would be that if you are using the truck so that you have a truck...you would need to gear it to do the work, making it less efficient as a commuter......I would look for an old Civic hatch (1977-1985) they are quite light, and there were a lot of them sold (cheap)...
Back to your truck though...I'm not sure what type of truck you drive but 10mpg? My 3/4 ton uses 14L/100kms (not sure how to convert to american gallons, but imperial that is 20mpg), and you are forgetting that you will need to charge the batteries...kWh on your power bill, it's not completely free power...it's definitely cheaper than gas, but not free.
Later.
the 10mpg comes from assuming this is a city only vehicle. not many folks will be able to find charging depots for homebrew electric cars. ok, assuming. :-)
those electric motors produce 100% torque @ 0-100% of its rated rpm range. given the motor will make around 100 ft lb, there isn't a need for 1st, or 2nd gears... or 5th for the matter. hauling a load is going to mean gearing down if its a half ton extra, but who does that in a commuter truck?
just thoughts :-)
Yup...you're right...brain fart :cookoo:...I don't use my truck in town (unless I absolutely have to)...vacation pulling the trailer, or heading to the job site...around town the GS does duty (except in winter...wifey's SUV)
You would probably be better off making a yoke that attaches the electric motor directly to the drive shaft and using the rear end ratio and tire size to match rpm to desired top speed...this will avoid parasidic loss throught he tranny... :thumb:
I still think the small hatch back is the better choice, or a small rear drive vehicle...old '70s Celica? Althought he truck does give you a lot of room to work with...
Good luck. :cheers:
Later.
I did consider a truck, some of the older toyota / nissan trucks would go well. I have a ready budget of 3500, max is about 5K.
What I want to do is build a usable one with a good enough 50-75 mile range or more. Basically I figure more $ i spend on the batteries, charge controller and motor the less I spend on the car itself.
You know sad part I donated my ford focus 2 years ago I should have kept it ( but I had no place to store it ), I was hoping to convert to a EV but the batt tech was hard to find then.
Quote from: madjak30 on November 10, 2010, 11:59:36 AM
Yup...you're right...brain fart :cookoo:...I don't use my truck in town (unless I absolutely have to)...vacation pulling the trailer, or heading to the job site...around town the GS does duty (except in winter...wifey's SUV)
You would probably be better off making a yoke that attaches the electric motor directly to the drive shaft and using the rear end ratio and tire size to match rpm to desired top speed...this will avoid parasidic loss throught he tranny... :thumb:
I still think the small hatch back is the better choice, or a small rear drive vehicle...old '70s Celica? Althought he truck does give you a lot of room to work with...
Good luck. :cheers:
Later.
holy carp thats a good idea ! the only downside i can think of is bump trasnmitting road noise back to the electric motor. a lovejoy style coupling would likely keep it all safe n secure. the bit about parasitic loss.. why didn't i think of that ? ;-)
ohhhhh, and that final drive (drive shaft, u joints, etc) will need a carrier bearing before the electric motor too. that's alot of stress to lever on a little electric motor bearing / housing.
man, i'm wanting to see this shape up. time warp time ? :D
Here's a site to whet an appetite for electric vehicles:
http://www.evalbum.com/
photos/techs to the max.
Maybe something like how a Bobcat works. The Diesel Engine provides the power to the hydraulic wheels.
Michael
I was searching craigslist for a bug to restore and came across this: http://seattle.craigslist.org/tac/cto/2055786904.html (http://seattle.craigslist.org/tac/cto/2055786904.html)