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Should you build your own electric car?

Kits to convert your car to electric are available, but are they right for you?

Brian Cooley Editor at Large
Brian Cooley is CNET's Editor at large and has been with the brand since 1995. He currently focuses on electrification of vehicles but also follows the big trends in smart home, digital healthcare, 5G, the future of food, and augmented & virtual realities. Cooley is a sought after presenter by brands and their agencies when they want to understand how consumers react to new technologies. He has been a regular featured speaker at CES, Cannes Lions, Advertising Week and the Publicis HealthFront. He was born and raised in Silicon Valley when Apple's campus was mostly apricots.
Expertise Automotive technology, smart home, digital health. Credentials
  • 5G Technician, ETA International
Brian Cooley
3 min read
FacFactory Five 818

The Factory Five 818 sports car is highly amenable to being built with an electric powertrain.

Factory Five

I know, it sounds like a Maker Faire fantasy, but should you build your own electric car? The short answer is no, yet a vibrant EV conversion cottage industry has been growing at least since Neil Young showed off his first LincVolt. We're in a DIY era that makes a formerly absurd proposition worth pondering, at least for a minute. Before you buy a Tesla Model 3, Nissan Leaf or Chevy Bolt, you might look into an EV conversion kit from a reputable maker like EV West or Electric GT to convert a gas engine car to an electric one.

Watch this: How to make your car electric with a conversion kit

What you need

The basic EV conversion recipe looks like this:

  • Donor car
  • Electric powertrain
  • Batteries
  • Connection and control components
  • Registration and taxes
Factory Five 818

The Factory Five 818 Coupe.

Factory Five

Let's use a recent email from one of our Cooley on Cars viewers, KC in Cincinnati, who wants to build an EV. He's looking at a Factory Five 818, a kit car that is sort of a cross between a Lotus Evora and a Porsche Cayman. The bare kit -- a "roller" with no powertrain -- costs about $10,000. Buyers normally drop in a 2002-2007 Subaru powertrain, but KC's going electric.  

That led him to EV West for an electric powertrain. The electric motor store recommends its Tesla Model S motor kit powered by five matching Model S battery modules. That powertrain comes to about $19,800 and gives the resulting car massive power and torque, world-class electric technology and 26.5 kWh of battery capacity. That capacity is small by today's production standards, but the 818 will weigh much less than almost any factory EV, so it should not only get up and go but do so for a good amount of miles per charge.

EV West conversion kit

Some of the components of an EV West conversion kit with a Tesla Model S motor and battery module.

EV West

The build sheet now looks like this:

EV West wiring diagram

If you wouldn't even know if you're holding this diagram upside down, building an EV is not for you. If, however, you can grok this at a glance, read on.

EV West

That adds up to around $33,000, not valuing the many hours to put it all together. When KC is done he'll need to present the car for inspection where he lives in Ohio to prove it meets all state safety equipment regulations. A quick glance at those regulations shows no red flags that would seem to make it hard to register it, as Ohio recognizes custom-assembled cars. 

And since the car is electric, there should be no headaches about smog compliance, though it appears a state referee will need to verify that the car is electric and tag it as such in the Bureau of Motor Vehicles database, since the Factory Five VIN won't indicate power plant as a factory VIN does. 

Finally, KC will find his registration fees are increased by new EV fees adopted in Ohio as of January 2020: An additional $200 upon first registration of a pure electric car and again every time it's renewed, designed as an offset to the fuel taxes these cars don't generate. But he'll earn that $200 back quickly due to the fact that he will have a lightweight car that will make the most of its low-cost charges.

Niche, but tantalizing

A project like this can give you a car with performance that will embarrass production cars that cost several times more, and you'll never see someone pull up alongside you in the same ride. On the downside, you have to build a car, and depreciation will probably be steep as it usually is with kit vehicles. You might end up asking why you ever undertook a project like this, but if you've read this far I suspect you're the type who can pull it off and enjoy the fact that electrification opens up a new golden era in car modding. For the right person.

If you've built an EV or converted a car to electric, send me a note and a photo: cooley@theroadshow.com.

First published on March 10.