I've heard a few people mention modifying a car to be fully electric and it got me thinking. I'll most likely never do it but I've been running the idea through my head as to how it could be done. So I'll spit out what I've got so far and if anyone has a better idea or way to improve what I've got then by all means say something, lets see how realistic we can get this.

I'd start off with a small standard car, maybe a truck so you can use the bed space for batteries. Take out the motor but leave the tranny, that way you don’t have to mess with gearing, axles, the whole back half of the drive train. Fab up a metal plate to bolt to the bell housing and use that as a mount for the electric motor. Find a high voltage regulator to attach to the gas pedal so that its still functional and load it up with deep cycle batteries. Add in a converter so that you can plug it into the wall at night to charge the batteries and you'd be set. This way you can keep most everything stock: lights, brakes, speedo etc.

Places to improve:

1. What kind of motor to use? Something powerful but not to energy sucking.

2. Batteries. 12V car batteries are big, heavy and about 80 bucks a pop. A better battery system could improve performance emensly. A 12V converter could run the cars electrical

3. Attaching the motor to the tranny. A standard would keep the motor at lower RPM (unless you wanna get crazy) and I don’t think you'd need a clutch with this setup, just let off the gas and shift. But fabbing up the attaching part would take some imagination.

So, how realistic is this setup? I'm no engineer here but I think it could work.

I can try and get you some info. One of my co-workers in Sioux Falls has a brother that makes electric cars. Most of them are built off a golf cart chassis but can do about 50. I will see what info I can.

I'm currently (no pun intended) finishing an electric vehicle.

Go with a 3 phase AC motor - the controllers are more expensive, but the motors are far more efficient (longer range for same charge) andrequire less cooling (no need for air vents on the motor, meaning less water damage if you go through a puddle).

Go with lithium batteries if you can scrape together the cash. If not, your car will be extremely heavy, or very short-range. Remember to try for one with an existing BMS (battery management system) and brand name charger, like BRUSA or something made for the pack. Make sure you get iron phosphate batteries, not cobalt oxide. The Cobalt ones make molecules of oxygen when charging, and heat up. Oxygen plus heat plus electric current = roasting marshmallows over the flaming hulk of what used to be your electric car. Do NOT use a 'converter' for charging. You're talking about deep charge/discharge cycles, and pushing a lot of amps into those batteries. There are many e-car chargers already on the market and will greatly prolpng your battery life.

If you can't afford lithium, go with NiCads. If you can't afford NiCads, use dry cell maintainance free automotive 12V batteries.

MINUMUM of 140 volt system. But with automotive lead batteries you'll have all the performance of a Ford Festiva in need of a rebuilt. I'm using a 312V system with a 105hp motor in an RX7 chassis, and calculations of rolling radius, drag coefficient, frontal area, final weight, etc. predict a 0-60 time of <7 seconds. (actually far lower, but I'm being conservative).

Start with a standard transmission car. Although you'll only need 2 gears (one for city, one for highway) you'll have far less transmission loss than an auto.

Weight is the enemy. Take off everything else you can. in my car, rather than using the clutch as in most backyard conversions, I drilled out the motor shaft to act as the pilot bearing for the tranny, a spline-to-spline adapter to connect the motor shaft to the transmission input shaft, and a machined aluminum adapter plate to connect the bellhousing to the motor as close as possible. Most "kits" for backyard conversions have you keep the clutch and use mickey-mouse multi part adapters that add unneccessary weight. Switch to run-flats or reposition your spare for best weight distribution.

You can use a ceramic heater, but it requires substantial rewiring of your HVAC logicon or switches. Best to buy a coolant heater for electric cars that goes outside the firewall and heats the coolant in your in-dash rad. Less re-plumbing, less headaches, and it hooks right up to the 12V accessory circuit.

Few questions manntis:

What are the dimensions of your electric motor and battery pack? I'm assuming its either in the hatch or where the gas tank used to be?

Is airflow through the engine bay enough to cool the motor or does it require some sort of cooling system?

What kind of range do you think You'll be able to get out of a single charge?

Without the heater (no need for heating in Hawaii) how much did you spend for the whole conversion? motor, battery pack, controllers etc.


I like the idea of using an existing car because most of the engineering has been taken car of. You don’t get as much freedom if you build something from scratch but its far less of a headache. And trying to register a known car must be easier then a pipe-framed creation.

not only thqat, but it takes 55 barrels - that's BARRELS - of oil in energy to manufature a car. Even if you replace your car with an electric vehicle, you have to drive it a few hundred thousand miles to break even on the oil energy you just threw away...

the motor is an Azure Dynamics AC55, up in the engine bay. I was going to use Thunder Sky batteries, but the US supplier promised delivery on October 20th and got 'round to delivering them on January 2nd, so I told them they can go fuck their hats. It worked out, since I've a new supplier offering me a 33 KWh pack for about the same price.

Most of the batteries are going where the storage bins used to be, behind the seats. The balance are going into battery boxes beside the motor, in the engine bay. Weight distribution is close to stock, all told, with a slight shift (2%) to the rear for better drive traction. The spare tire well is getting the chop as I'm dropping the floor to make a larger cargo area, now the gas tank and muffler are gone.

Hard to say what the final cost is, as the motor, controller, pack, bms, charger, etc. were provided as part of the documentary I'm making on electric vehicles.I do know we're paying about $11,000 for the batteries, and the motor retails for around $5,000 with the controller being about the same. Remember, though, that the controller is basically a purpose-built computer that withstands temperature extremes and makes the power flow from the batteries to the motor as efficiently as possible, based on potentiometer input.

I've mounted the potentiometer on the firewall near the hood latch, and attached the throttle cable. One could mount it directly to the pedal, but once I put the dash back in space is at a premium down there.

I take it the batteries coming so late affected everything in this build?

Can you supply us with some teaser pics?

I take it the batteries coming so late affected everything in this build?

Yup - the battery boxes have to be re-engineered, a different charger selected, and the controller reprogrammed.

Can you supply us with some teaser pics?

Nope. Not at this time, at least. Once the broadcaster okays what I have internet rights to, I'll be publishing some galleries and clips.

This I wanna see :)