Gavin Shoebridge – an electric vehicle nut, a keen environmentalist

                Electric Car Conversion Blog By Gavin Shoebridge

March 26th, 2010 at 2:59 pm

The Three Main Parts of An Electric Car

If you’re looking to convert a car to run on electricity, you’ve probably got a thousand questions racing through your head. I know I did when I first started. One big question is about which are the main parts of an electric car. Luckily there are only three.

Electric Motor with Gearbox Adapter Plate

Electric Motor with Gearbox Adapter Plate

1: The Electric Motor.

This one’s kinda obvious; it’s the motor which propels the car. The beauty of the electric motor is that it has only one moving part, unlike the internal combustion engine which typically has over a hundred moving parts. This alone makes electric motors a very reliable source of motive power. When choosing an electric motor, you’ll need to find one that’s suitable for your car’s system voltage, and the car’s voltage will determine what sort of performance your car will have. DC motors are tolerant things however, and you don’t have to be spot-on with your voltage. Just keep an eye on your motor’s temperature while you’re getting used to your electric car. Expect to pay anything from $0 for a used electric forklift motor, to $3000 for a high performance motor for your conversion.

A Typical Curtis Controller

A Typical "Curtis" Controller

2: The Controller.

The controller’s job is to act as a floodgate between the motor and the batteries. It’s controlled by your existing accelerator pedal, so the more you press down, the more power goes to the motor. Because modern controllers have no moving parts, quality looked-after versions should last decades without needing components replaced. The popular Curtis controllers for example have less than a 3% failure rate. The controller is a vital component – without it you’d
have either full power or no power. Depending on your desired performance, expect to pay between $0 for a used forklift controller, to $5000 for a high performance, high voltage controller.

A Popular Lithium Iron Phosphate (LiFePO4) Battery

A Popular Lithium Iron Phosphate (LiFePO4) Battery

3: The Batteries.

Thanks to laptop computers and cellphones, battery technology has improved in leaps and bounds over the last 20 years, with lithium batteries being the desired choice for every converter. Sadly they’re still expensive to manufacture and buy, so for the timebeing many converters still use lead batteries, similar to the ones that start your car. Due to weight and size issues however, the only benefit of lead batteries is the cost, so let’s assume you’re on a budget.
Batteries are an area in your electric car where you have plenty of choice in makes, models and sizes. To cut costs further you could even look into battery rejuvenation, where free second-hand batteries are brought back to life through desulphation (though I’ve tried it myself with fairly lackluster results).
While I’m always looking (and encouraging) people to try new things, I’ve always mentioned that batteries are one area in your electric vehicle where you should not cut costs.
Understandably however, the costs ultimately rule our conversion outcomes. So to buy batteries you have a couple of options. How many batteries you’ll need depends on the size of your pack (which depends on how far you want to drive per charge).
Therefore if you want a usable local range of just 20 miles, then your battery pack might cost between $0 for second hand rejuvenated lead batteries, up to $2000 for brand name deep-cycle lead batteries.

There you have it. Those are the three main parts of an electric car, and it should give you an idea of what price ranges there are, and what you could aim to build your car for.
Electric vehicles are very simple things, but there’s still much to be explained, from choosing the right motor, to using lithium batteries for long range driving, to joining your motor to your existing gearbox. You’ll come across each of these questions (and more) during your conversion. Don’t be put off though, if I could do it then anyone can!

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    10:01 am on June 3rd, 2010 1


  • gavin
    1:43 pm on June 3rd, 2010 2

    Hi Gavin (that’s a good name by the way!). No problem, you could have a car like the White Zombie but as with any high performance car it’ll cost more than a typical conversion. I recommend checking out and looking at the performance/cost specifications of some of the vehicles on there. That’ll give you an idea on approximate cost, then if you think you can do it (anyone can really) then I recommend grabbing a copy of my tutorial videos & ebooks to make the whole process simple.
    Go for it mate – and good luck!

  • Schalk
    5:50 am on November 18th, 2011 3

    Hi there , I dont know much about working on cars, but i would like to convert my Smart for two into an electric car.

    I will need someone to do this for me.

    Is it possible and what would the approximate costs be to do this?

    Thx, Schalk

  • Elmar Vollbier
    8:46 am on December 22nd, 2011 4

    It strikes me as enormously interesting that a normal gas-operated car can actually be converted into an electric car. However obviously it is worth it. How long did it take you to transform the car?

  • ganny raji
    10:53 pm on February 4th, 2012 5

    i want to buy step by step guide of building electric car

  • Flavia
    10:24 am on March 15th, 2012 6

    Randy CJuly 10, 2010 Personally, I’m not sure I want to do business with GM ever again. The way they tteerad the people that were willing to put up with GM’s B.S. just leasing the EV1. Then how they were tteerad when GM decided to terminate the “experiment” leaves a bad taste in my mouth. And then, to add insult to injury, billing the leasees hundreds of dollars for every ding and scratch in the paint on a car whos next stop is a car crusher. How do I know they wont come and take the car back after 3 years?Compared to the EV1 the Volt is a not so great electric car. The 1999 EV1 got 140 miles per charge while the 2011 Volt only gets 40, what’s up with that poor number? If you can design a car that got 140 miles why bother building one that gets only 40? The Volt is the electric car that the oil companies want. It has low range and has a gasoline engine, which means GM’s good buddy Chevron still makes money. There are going to be better performing cars on the market in 2011 like the Tesla Model S and the Miles XS500. Not to mention if ZENN gets its EESTOR powered 200 mile electric car working as promised.

  • Chris
    11:56 pm on September 25th, 2013 7

    Hi Gavin, Schalk
    Has anyone converted the smart fortwo I have one with a bust engine I need to convert
    Thanks Chris

  • Derek
    11:59 am on December 19th, 2014 8

    Why use batteries?
    Don’t like them.
    I have two different soreses that don’t need the batteries.
    I tried to get Tesla to buy into mine and they refused. We could
    Go 1800 hours on a charge. That is a lot of driving. In fact we could put one in a simi
    Truck. But, fuel companies don’t like that.

  • krishna kadam
    1:12 am on August 9th, 2017 9

    I am an electrical and electronics engineer,currently in final year. I want to take up my major project in this field. So I am searching for some sections of electric car where I can find some challenge to improvise. So what all options have I got to work upon. I would be really grateful for any of your suggestions. Thank you

  • jaime
    10:08 am on December 11th, 2017 10

    can explain more about the the electric motor………. PLEASE!!!!!!!!!!!!!


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