Author Options:

Build an Electric Car Answered

Want to convert your car to all-electric on the cheap?  Check out bennelson's awesome Instructable, Build your own Electric Car! 

Ben walks you through the steps of converting a Geo Metro (purchase price $500, gas-requiring parts sold for $550) to run on a forklift motor and 6 12V batteries.   According to his calculations, the car gets the equivalent of about 130 mpg.  Not bad for an entirely self-taught mechanic!

Check out the video of his converted Metro going up hills:

Sounds easy, right?  So when are you planning to convert your car or truck?

This post has been sponsored by Pepsi. The Pepsi Refresh Project celebrates the people, businesses, and non-profits with ideas that will have a positive effect on our world.


do electric cars have power steering

It depends on the car you use. If you use a car that has power steering than it will just waste battery power and runs your battery dead sooner.

Now how about through the terrible Ohio snow?? From what I've read, batteries don't do so well in cold weather.. Or 12 inches of snow..

I drive an electric truck to school everyday, including through our super-snowy winter. The weight of the lead-acid pack gives it tremendous traction on slick streets, and the enormous low-end torque lets it plow over snowbanks. It's my favorite car to drive in bad weather. The battery pack has 1" Styrofoam insulation around it, and the heat generated through charge/discharge cycles, coupled with the high thermal mass of lead, keeps them plenty warm. This past winter, we spent about three weeks with the temperature never getting above 10degF, and the temp probe in the battery pack never dropped below 65. In very cold climates, or if insulation isn't possible for some reason, battery warmers can be slipped in and around the pack.

LeerCourier Shell.jpg

Awesome! That's convincing.  Is the whole bed filled with batteries?  How many miles are you able to go between charges?

The battery box sits in the front of the bed, and is built to hold 20 6V batteries. It extends back to just in front of the wheel wells. Six batteries in the old pack of 20 failed (cheap Chinese crap batteries), so it's now running on 10 12V gel-cells. With the old pack it had something like a 40-50 mile range, with the reduced pack it's probably closer to 20 or so...we haven't wrung it out all the way, the current pack is a collection of used batteries that we're babying to last as long as possible (or until we get some other projects out of the way).

Cool, how much have the batteries cost you?  20 miles won't get me to school and back though : /..

.  Yes, battery performance is dependent on temperature, but ...
.  Modern batteries still have plenty of juice at sub-zero temps - or else you couldn't start your car in Winter. There will be a definite impact on power and range, but not that bad.
.  Batteries self-warm as they put out power.
.  The amount of snow will not affect the batteries, just the ambient temperature. If the batteries are placed over the drive wheels, they will improve traction.

You have some good points there : ).. I honestly didn't consider the whole self-warming thing : )..

But if I run out of juice, who wants to be stuck in the snow??..


Invest in some new nifty solar panels that are flexible.. can't recall what they actually call them, but you can walk on them and all kinds of stuff.  Maybe when you park your car can charge just a little to increase range.

Sure, and a pop-up wind turbine would be nice.  But if it's snowing won't the snow block the panels?  That, and "invest" isn't really something I can do at my age, although it sounds like a cool technology.

well actually the technology is there that even with something like 6 inches of snow the panel will still produce electricity.  Museum of Science and Industry in Chicago - Smart Home. 

Really?? I suppose I should do some testing..

And if you run out of gas in the Hummer, who wants to be stuck in the snow?  That argument has nothing to do with electric vehicles, it has to do with being properly prepared for the weather.

Wow, let's all jump on the one person not completely thrilled with electric cars... : )

My dad does own a Hummer, it has a 5-cyllinder engine and gets 25 mpg, better than most cars : )..

If you run out of gas, you just wait for a gallon to be brought to you by a family member or AAA, then you put it in your car, drive to a gas station, fill 'er up, and get on with your life : ).. And not have to pay for a tow in the snow..

In case the text doesn't show it, I'm not trying to be angry or aggressive or offend anyone, I like talking about cars and ways to fuel them : )..

> Wow, let's all jump on...
.  What's with the persecution complex? No one has jumped on you. You made some false statements and were gently corrected. No big deal.

I was partially joking about being jumped on.  However, most of the people I have talked to see electric cars as a technology that is nice, but just doesn't appeal to a lot of people, and has had a lot of trouble taking off.  I find it interesting that people out there actually like electric cars, and that more than one person replied to my comment. That's all : )..

I prefer noisy, smoky gas-guzzlers,  but one of these days the electric guy will get everything just right, and we'll all be lined up to get our electric-mobile. 

Remember the early Cadillac 4-6-8 engines?  Neat idea, but most people just disabled the "computer" and left them set on 8.  These electric things may be the next Edsel for all I know, but right now, they have more of a Yugo feel to me.  

 On a serious note, they still seem like TOYS.  I like toys, but I refuse to spend good money on them.  I'd just as soon have a $500 Cutlass or Regal.   Now when there are good used electrics going for $1000 or so, I'll probably have a yard full of 'em.

Tesla Roadster. Rich mans toy, why yes it is.  is it a car that can drive you anywhere you need 355 out of 365 days a year. yes it is.

The Teslas are sweet.  They'd likely be my first choice.  But what's the range on those? I drive 135 miles every day, and my wife usually drives the car another 40 miles.  Although the performance is awesome, would the range keep up with my needs?

They are.  As far as I know they will go about 100 miles between charges, but it depends on where you're driving it, be it highway or city.

I'd agree that Tesla's are probably the best current electric cars.  However, what if you need to take two of your friends to wrestling practice? Cars with two seats aren't very practical right now..

Not at all, they sound before my time : )..

I agree with the toy thing, many times when I'm talking to other people they bring up the word "toy" or "golf cart"..

Right, electric motors can be great in cars! They suit drag racing really well.. I could deal with a series hybrid possibly, but from what I've read gas-hydraulic hybrids are far superior to gas-electric, so I'd have to find one of those : )..

If a battery fails, you just wait for AAA to bring you out a replacement (they do that!).  Then you drive home, or to a motel, or whatever, and plug in for the night.  And not have to pay for a tow in the snow... :-)

Oh, if the snow is so bad that you're stranded, chances are the tow truck guys aren't going out in it either (like they say in Urban S&R, you don't want the rescuer to become another victim).

And I'm sorry if it sounded like I was jumping on you.  Pity you can't get tone of voice or proper facial expressions into a plain text message.

Do they? Would I have to buy the battery from AAA? Obviously I'd have to buy the gas too, but a gallon of gas would be cheaper than a whole new battery, right? : )

I'm not saying that it's so bad you're stranded, just bad enough that it's bad and you wouldn't want to run out of gas in.

Nahh it's not you.  I guess I find it interesting that I've had a bunch of responses to my comment that defend electric cars, as I assumed they were mostly a joke.. Just an opinion I'm not used to getting : )

That's awesome!! We have done that before in the huge piles of snow the plows dump right on our mailbox

You could also invest in battery warmers, or park the car in a garage..  This instructable makes me want to find a metro (thought I would never say that) and put a bunch of batteries in it!! LoL  Good Work!

Hm, sounds like an excuse to move south. ;)

True : ).. or just wait until the "global warming" makes us up by the Great Lakes the next prime vacation spot, when we don't have snow : )

Or buy/build a heated garage - batteries do perform worse when running in the cold, but its really the idle/off states when temperature can zap the capacity.  Keeping the batts at a mild/lukewarm temperature when not in use may help.
As an alternative: a car collector down my street built his own plug-in electric car, but due to zoning laws he couldn't widen his garage.  He came up with two solutions: for normal winter nights in the home of the Golden Snowball (Syracuse, NY), he keeps the interior of his car warmed with a modified space-heater (not the safest of methods, but whatever works!), and for storms or extended periods of non-usage, he modified his battery packs into a rack and rail system.  Now all he has to do is back into his driveway, disconnect the electricals, slide the whole system on rails onto a large-wheeled cart, and wheel them into his house.

That could happen : )..

Space heaters soak up a ton of energy, just to add to your car's carbon footprint, just saying.. 

That sounds like a bit of work, but also like a pretty good system, it should make replacing the batteries when they won't hold a charge anymore really easy : )

So how much coal does it take to charge it? With over half of all power coming from coal, I am wondering, are we still just moving the tail-pipe?

If you look at it that way, all energy is nuclear. its just where we put the reactor.

silentchugo don't hate, when you have a better more feasible idea please share it here. How much coal does it take to power the computer you are using to down a person that made an  electric car?

Sure its not fully clean but we won't EVER be there until solar, wind and geothermal drops in price enough so every common man can afford it.

It's not hate, just knowing what it takes to do things. I have seen an Li mining operation. Mining operations are big and dirty, ignoring that does not change it.


8 years ago

130mpg? Gallons of what? It's electric.

Power usage equivalency - electric energy expended compared to gas mileage.

can it be done this way?
Price of a gallon of gasoline / price of a kilowatt = number of kilowatts for that same price
then see how many miles you can make with a single kilowatt, then multiply that by the # of kilowatts you got for the price of a gallon = the number of miles for the same price of a gallon of gasoline

Is it right?

canida BTW that was an outstandingly awesome Instructable you made. thanks for sharing

This isn't my Instructable - it's bennelson's.  I'm just pointing people to it because I think it's awesome too. ;)

I'd say kelseymh's method is most likely easier and more accurate.  Engineer that I am, I am tempted to try the math you laid out, but you also have to deal with efficiencies of the standard gas engine and electric motors, batteries, etc.  In terms of price alone, the price of a kilowatt (which I've never seen priced in that way - we always are quoted a kilowatt-hour cost which never matches what our usage is due to mathmatical gymnastics by National Grid) includes service charges, fees, "delivery", sourcing, etc. etc. etc.
For a first-order estimate, this would probably work though.  I'd say give it a try - there are many well-documented electric builds that give energy comparisons, so if you can find all the proper numbers, see if they match the equivalent values!

"Equivalent of 130 mpg".  As Valhalla stated, this is "energy equivalence."  It has become standard in the electric vehicle industry, in order to provide consumers with a direct comparison of the efficiency of these vehicles with ordinary IC engines.

When a vehicle (e.g., a hybrid) is running pure electric, it is not, as you say, burning any gasoline at all.  However, it is still using energy, which will have to be recovered or restored.  If you ask the question, "How much gas would I have to burn (e.g., in a generator) to recharge those batteries?" then you can compute an effective or equivalent miles-per-gallon value.

Exactly what kelsey said. You've got to be able to compare efficiency somehow, so this is a best-estimate conversion.