Stellenbosch University converts Toyota taxi into EV, testing to start shortly

8th September 2023 By: Irma Venter - Creamer Media Senior Deputy Editor

The Department of Industrial Engineering at Stellenbosch University (SU) has joined forces with Rham Equipment to convert a Toyota Hiace Ses’fikele minibus taxi into a battery electric vehicle (EV).

The university’s team, consisting largely of postgraduate students, is headed by Professor Thinus Booysen, who holds the research chair in the Internet of Things.

Toyota South Africa Motors is aware of the project, but is not a participant.

The South African National Energy Development Institute provided funding for the project, and the Transport Services division at SU donated the minibus.

The Ses’fikile is by far the most popular minibus taxi in South Africa. It is assembled at Toyota’s plant in Durban.

Booysen says the prototype taxi is currently being verified as roadworthy, which will be followed by performance testing to see how well the vehicle matches the department’s various simulations.

This process will, however, make use of weights, and not real passengers.

“More than 70% of public transport trips in South Africa are by minibus, which is why we are hoping to encourage the retrofitting of some of the 250 000 minibuses in the country with electric propulsion,” says Booysen.

“These will be cheaper than new EVs, with retrofitting also much more environmentally friendly than producing brand-new EVs.”

Booysen says the conversion cost about R750 000 in hardware, and took 500 hours to complete. He believes, however, that the price tag can be reduced to R470 000 if working at a scale of 1 000 vehicles at a time.

The converted taxi can still accommodate 15 passengers, plus the driver, despite the added weight of the lithium-iron-phosphate (LFP) battery.

LFP batteries are viewed as more thermally stable.

The range on the electric vehicle is between 100 km and 120 km, and the maximum speed 120 km/h.

The minibus’ electric motor offers 90 kW of power, with battery capacity at 53.76 kWh.

One of Booysen’s team members, Stephan Lacock, who is completing his master’s degree in electronic engineering at SU, funded by bus operator Golden Arrow, helped design the retrofitted minibus, along with Rham Equipment.

He explains that the team removed the minibus’ internal combustion engine and its associated components, such as the petrol tank, manual transmission and radiator.

Throughout the development process, the retrofit had to comply with national road safety regulations, particularly the requirement not to make any permanent changes to the minibus chassis (base frame), such as drilling or welding, as well as the specific weight requirements.

“Rham Equipment and our research team have successfully created a reproducible kit that includes the main components of the electric powertrain or system that propels the vehicle forward,” says Lacock.

“These include an electric motor, inverter, charger, electronic control unit and a single- speed reduction gearbox. Also, the powertrain is connected to a custom-designed battery pack that meets the specific operational needs of a minibus.”

Lacock says one of the standout features of the retrofitted minibus is its regeneration system, which harnesses the energy generated during deceleration and downhill driving, thereby enhancing the vehicle’s energy efficiency and overall range.

“Thanks to the inclusion of a 20 kW charger, the minibus can be efficiently charged in just under three hours,” he adds.

What’s Next?
Booysen hopes to use the vehicle to prove a number of simulation models within the next two months.

Following this, the next 18 to 24 months could be spent creating a locally made electric motor, inverter and vehicle control unit.

These components, he believes, can be produced locally with relative ease. Battery cells could prove trickier, and costly.

Ultimately, the goal is to create a local assembly line for commercial vehicles.

Booysen and his team also stand ready to move on to the retrofit of a Golden Arrow bus, which should be completed in October.

Booysen believes that it is time for South Africa’s automotive industry to move into the EV space more aggressively.

“With this venture, we want to help build the skills that will be needed to manufacture EVs locally and also create awareness about how much we could save with electric taxis.”

Vehicle manufacturers in South Africa have a window of opportunity to open plants in Africa to produce EVs locally, says Booysen.

“Most of the locally manufactured petrol cars are being exported and this boon to the economy will end with developed countries transitioning to EVs in the run-up to (or before) 2035.

“Remaining in the slow lane of the EV transition could put thousands of jobs at risk.”