A conversion kit turns a gas car into an electric one, but the process is expensive, time-consuming, and rarely worth it for most owners

An electric car conversion kit is a collection of parts — motor, battery pack, controller, wiring harness — designed to replace a vehicle's internal combustion engine with an electric drivetrain. In theory, you buy the kit, install it in an existing gas car, and drive electric. In practice, the math almost never works out. A complete kit costs $4,000 to $15,000 or more, installation labor runs $5,000 to $20,000 depending on the shop and vehicle, and the result is a car with less range, less power, and less reliability than a new electric vehicle you could buy for the same total money.

The only scenario where conversion makes sense is if you own a classic or rare car you want to preserve and have no other use for the money. For everyone else — including people with older gas cars they want to keep — buying a used electric vehicle is faster, cheaper, and safer.

Key Takeaways

  • A complete conversion kit plus professional installation typically costs $10,000 to $35,000 total, which is more than many used electric vehicles.
  • The resulting car will have a shorter range and slower acceleration than a new or recent used EV, and no manufacturer warranty on the drivetrain.
  • Most shops that do conversions are small operations without the infrastructure to handle repairs or warranty claims later.
  • Insurance companies often charge higher premiums or refuse to cover converted vehicles because they fall outside standard safety testing.
  • A used Nissan Leaf, Chevy Bolt, or Tesla Model 3 will cost less, go farther, and require no installation work.

What's actually inside a conversion kit

A basic kit includes an electric motor (usually 20 to 100 kilowatts), a battery pack (typically 40 to 100 kilowatt-hours), a motor controller that manages power delivery, a charging onboard charger, and the wiring and connectors to tie it together. Some kits add a DC-to-DC converter to power the car's 12-volt accessories, and a few include a thermal management system to keep the battery from overheating.

The quality varies enormously. Budget kits use older lithium chemistry or lead-acid batteries with poor energy density, meaning less range per pound. Mid-range kits use modern lithium iron phosphate (LFP) cells but may skimp on the motor controller or cooling system. Premium kits from companies like EV West or Canadian Electric Vehicles use automotive-grade components, but they cost $15,000 to $25,000 before labor.

None of these kits come with the engineering that goes into a factory electric car — crash testing, thermal modeling, software optimization, or redundant safety systems. You are buying parts, not a validated system.

Why the total cost makes conversion a poor choice

The kit itself is only the beginning. A professional conversion shop will charge $8,000 to $20,000 in labor to remove the engine, transmission, fuel tank, and exhaust system; mount the motor and battery; run new wiring; and integrate everything with the car's existing electrical system. Some shops charge by the hour (typically $75 to $150 per hour) and the job takes 200 to 400 hours. Others quote a flat rate for specific vehicles.

Add in unexpected costs: structural reinforcement if the battery is heavy, custom motor mounts, modifications to the cooling system, and testing and tuning after installation. A realistic budget for a professional conversion is $15,000 to $35,000 total.

For that same money, you can buy a used 2020 or 2021 Nissan Leaf with 150 miles of range, a used Chevy Bolt with 250 miles of range, or a used Tesla Model 3 with 200+ miles of range. All three come with remaining manufacturer warranty, established service networks, and insurance that treats them as normal vehicles. The converted car comes with none of that.

Range and performance are usually worse than you expect

A conversion kit's real-world range depends on battery size, vehicle weight, and driving conditions. A 60-kilowatt-hour battery in a 3,500-pound car might deliver 150 to 200 miles of highway range under ideal conditions. In winter, on hills, or at highway speeds, expect 100 to 150 miles. A 100-kilowatt-hour battery pushes that to 200 to 250 miles, but adds $3,000 to $5,000 to the kit cost and makes the car heavier, reducing efficiency.

Acceleration is often disappointing. A 50-kilowatt motor will move a car from 0 to 60 mph in 12 to 15 seconds — slower than most modern gas cars and much slower than any new electric vehicle. A 100-kilowatt motor cuts that to 8 to 10 seconds, but costs more and draws more power, reducing range further.

Charging speed is limited by the onboard charger included in the kit. Most kits come with a 6.6-kilowatt charger, meaning 8 to 12 hours to fully charge a 60-kilowatt-hour battery on a Level 2 home charger. DC fast charging is rarely included and requires expensive aftermarket additions.

Insurance and registration create ongoing problems

Insurance companies treat converted vehicles as custom builds, not production cars. Many insurers will not cover them at all. Those that do often charge 20 to 50 percent higher premiums than a comparable new electric vehicle, because the car has not been through crash testing and the insurer has no data on repair costs or safety performance.

Registration varies by state. Some states require a safety inspection by the Department of Motor Vehicles before a converted car can be registered. Others allow registration but flag the vehicle as "specially constructed" or "kit car," which can affect resale value and insurance availability. A few states have no clear process, leaving you in legal limbo.

When something breaks — the motor controller, the battery management system, or the custom wiring — you will likely have to return to the shop that did the conversion. If that shop has closed, moved, or gone out of business, you may have no way to get repairs. Factory electric vehicles have dealer networks and third-party repair shops across the country.

When a conversion might make sense

Conversion is worth considering only if you own a vehicle with significant sentimental or collector value — a classic Volkswagen Beetle, a vintage Porsche 911, a first-generation Bronco — and you want to preserve it while making it electric. Even then, the cost is high and the result is a one-of-a-kind car with no resale market.

If your goal is straightforward to drive electric and you currently own an older gas car, selling that car and buying a used EV is almost always the better path. The used EV market has thousands of options in the $15,000 to $30,000 range, all with warranties, established service networks, and insurance that treats them as normal vehicles.

DIY conversion is theoretically cheaper but requires advanced electrical and mechanical skills, access to a lift and diagnostic equipment, and months of work. Most DIY conversions take 500 to 1,000 hours and still end up costing $8,000 to $15,000 in parts. The result is a car you cannot easily sell and that may not be insurable.

Better alternatives if you want to go electric

The used electric vehicle market has grown dramatically in the past three years. A 2020 Nissan Leaf costs $12,000 to $16,000 and has 150 miles of range. A 2021 Chevy Bolt costs $18,000 to $22,000 and has 250 miles of range. A 2019 or 2020 Tesla Model 3 costs $20,000 to $28,000 and has 200 to 250 miles of range. All three are cheaper than a conversion, come with remaining warranty, and can be serviced at established shops.

If you want to keep your current car for other reasons, consider whether you actually need it to be electric. If you drive fewer than 100 miles per day and have access to home charging, a plug-in hybrid (like a Chevy Volt or Toyota Prius Prime) might be a better fit than conversion. You get electric driving for daily commutes and gas backup for longer trips, without the cost and complexity of a full conversion.

Frequently Asked Questions

How long does an electric car conversion take?

A professional shop typically needs 200 to 400 hours of labor, spread over 4 to 12 weeks depending on the vehicle and kit complexity. DIY conversions take 500 to 1,000 hours over several months. The timeline depends heavily on whether the shop encounters unexpected issues during removal of the original drivetrain.

Will a converted car pass inspection and registration?

It depends on your state. Some states require a safety inspection by the Department of Motor Vehicles; others allow registration with a "specially constructed vehicle" designation; a few have no clear process. Contact your state's DMV before starting a conversion to understand the requirements and timeline.

Can I get a loan to pay for a conversion?

Most banks and credit unions will not finance a conversion because the result is a custom vehicle with no resale value and no collateral. Some specialty lenders or personal loan programs may work, but expect higher interest rates and stricter terms than a car loan.

What happens if the conversion shop goes out of business?

You lose your warranty and your service relationship. If the motor controller fails or the battery management system malfunctions, you will need to find another shop willing to work on a custom build, which is difficult and expensive. This is a major risk with small conversion shops.

Is a converted car cheaper to maintain than a gas car?

The motor and drivetrain have fewer moving parts and lower maintenance costs than a gas engine. However, the battery pack is expensive to replace (typically $5,000 to $15,000 depending on size), and if something goes wrong with the custom wiring or controller, repair costs can be high because labor is specialized and hard to find.