Converting your petrol or diesel car to electric — What you should know

Retrofitting a conventional petrol or diesel car with an electric vehicle (EV) driving system is feasible but should only really be considered to breathe new life into older cars.

That is according to Thula Solutions chief technology officer Mike McDonald.

Thula Solutions is the company behind the first South African-made electric 4×4, built in partnership with Brandt Radical Vehicles (BRV).

The Thula Electric Safari Vehicle (ESV) was designed specifically for game watching in national parks and private reserves.

Although it was built as an EV from the ground up, McDonald explained that the first EV the company customised was a retrofitted Land Cruiser called Casper.

Thula Solutions founder and CEO Gary Davies rebuilt Casper with an electric driving system.

“The retrofit was awesome and allowed him to really test the idea of an EV in the bush and validate the idea that a silent vehicle would be a step up in terms of the game drive experience,” said McDonald.

Casper, the electrified Land Cruiser by Thula Solutions
The modification of the Land Cruiser included the addition of a touchscreen.

However, McDonald said Casper sadly”wasn’t a very good EV. It could only drive about 40km on a charge and had a top speed of 40km/h.

On one occasion, the car was charged by an elephant with a full load of guests, and Davies had to drive up a hill at maximum speed.

The EV could not increase the distance between itself and the elephant for about 500 metres. Fortunately, the animal gave up the chase after a while.

“Additionally, there were a bunch of cooling issues, and when retrofitting an internal combustion engine (ICE) car to EV, you have the problem of inheriting whatever the manufacturer thought was best for their design,” McDonald said.

“We were constantly fighting with space constraints and other issues in the conversion process.”

McDonald said that is why the Thula ESV was built from scratch as an EV.

The game driver boasts a range of up to 250km and a 160kW/980Nm drivetrain, which means its top speed will be no less than a typical, reasonably powerful petrol passenger car.

Its silent operation makes for a more immersive and less intrusive game-viewing experience.

McDonald said the company had seen significant interest from people who wanted to convert their vehicles, but that was not its primary business.

“We normally try to redirect them to Steve Blatherwick in Nelspruit.”

Nevertheless, McDonald said he remained a huge advocate of EV conversions, especially when classic cars are involved.

“With the cost at about R400,000 for a conversion, it is often not worth it for a vehicle that doesn’t have a lot of value remaining,” he said.

Thula said many companies supply kits and training, but it preferred to use LegacyEV in the US for its own builds.

“They also provide training and education for those starting out,” he said.

McDonald said if the vehicle’s electric system is kept at 100 volts, then most of the tooling required for mounting the electric motor and components could be found in a regular car workshop.

However, he cautioned that a 100V DC system must still be treated as dangerous and required correct safety training, although not to the same levels as what’s necessary for the 400V or 800V systems in mass-produced EVs.

The only parts that require specialist hardware are the custom mounts to fit the components into a new body.

“You can always get them made by someone with a computer numeric control machine or laser cutter and fabrication shop,” McDonald advised.

One illustration of a successful EV conversion McDonald worked on was a side project for Davies — turning an old and rusted first-generation Volkswagen microbus shell into a working electric car.

“Over about 18 months we got it painted and refurbed, and then I installed an electric drive system and battery,” McDonald said.

“It’s now a lovely and reliable vehicle that still only has about 100km of range but is great for a small town at the beach where it lives.”

McDonald said the bus was suitable for daily driving in a town as long as it was plugged and charged while at home.

He said the bus could travel about 5km on one kWh, which works out to a running cost of R0.68 per kilometre based on a price of R3.40 per kWh, substantially more affordable than the per-km price of its original VW engine.

“That said, it will take a lot of driving to recoup the install cost,” McDonald stated.


Another advantage of electric adoption is that the maintenance of a successful conversion would be minimal.

“You need to keep doing regular maintenance on the brakes and moving parts, and on a classic car, these often need work,” McDonald said.

“In terms of the motor and batteries, they should run for years without a worry, though.”

For those considering conversions of newer cars, McDonald warned that no manufacturer would respect any warranties or safety ratings once you put an EV motor into their vehicles.

Below are more photos of the electric VW Microbus McDonald converted for Davies.

Converted VW Microbus

VW Microbus shell before rebuild
Electric VW Microbus after refurbishment
Electric VW Microbus at a charging station

Now read: I drove the Volvo XC40 Recharge Twin for 3 months — why I’m hooked on electric

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Converting your petrol or diesel car to electric — What you should know