Battery-electric

Examples: GM EV1, Tesla roadster and saloon, Nissan Leaf, Misubishi MiEV

The godfather of the modern electric vehicle was the General Motors EV1, the first electric car from a major manufacturer.

The EV1 wasn’t based on an existing vehicle and was produced in limited quantities (1117 of them) between 1996 and 1999. Customers, although they could only lease the vehicles, loved them – but the project was dogged by politics. Eventually General Motors recalled the vehicles and crushed all but a few. The Chevrolet Volt hybrid (more on that below) is the spiritual successor to the EV1.

Electric motors are highly efficient and provide more than enough grunt – the problem is getting enough power to them. Battery-electric vehicles have a rechargeable battery pack that powers an electric-drive motor. There’s no petrol or diesel engine. Recharging is generally done from a standard power socket (which takes several hours) or sometimes from a high-current quick-charge unit. If battery-electric cars become commonplace then recharge stations could possibly be fitted to car parks and parking meters.

Petrol is 77 times more energy dense than the latest lithium-ion batteries – so battery vehicles have a way to go before they can match the range of a petrol or diesel vehicle. Even the latest batteries still leave the vehicle heavy, with limited range and long recharging times. Currently, you can have a high-performance battery-powered vehicle with low range, or a longer-range vehicle with low performance. Only the Tesla roadster comes close to having both (more on that below, too).

Mitsubishi MiEV

Mitsubishi MiEV test drive

We recently put all this theory into practice and “test drove” a Mitsubishi MiEV full-electric car. It’s based on the Mitsubishi iCar, with a lithium-ion battery pack providing the sole power for the car – there’s no petrol engine back-up as is the case with hybrid vehicles.

Visually there’s nothing to distinguish a MiEV from a standard iCar – outside or in. The fuel filler flap opens to reveal a socket for the charging lead, which plugs into a standard  household socket. Charging with the standard built-in charger takes seven hours. An external 30-minute charger is also available, but to use that you need access to a 3-phase electrical supply.

Our verdict
The MiEV is like any other car: you turn the key, put the “transmission” in drive and press the accelerator. But there are noticeable differences. The first is the lack of noise. Electric motors make very little noise – none when stationary and just a slight whining when working. The spirited performance is also noticeable: the MiEV can easily out-accelerate its petrol equivalent.

The downsides are range and cost. The MiEV is only suitable as a city or commuter vehicle. Its range is about 160km – but this varies with driving style, just as it does with a petrol car.

Cost is the biggest killer. Our test model was an engineering prototype: production models could be available in very limited numbers later this year – prices are yet to be announced.

Other battery-electric vehicles

Nissan has also got into the act, with the all-electric Nissan Leaf. This 5-door hatchback is based on the existing Nissan Tiida but is powered solely by an 80kW electric motor that’s fed by a lithium-ion battery pack. Its range is around 160km. The Leaf is due to go on sale (overseas) late in 2010.

In range and performance, the Tesla roadster is the nearest all-electric equivalent to a petrol vehicle. Production of the Tesla roadster – which is based on the lightweight Lotus Elise sports car – began in 2008. The battery pack consists of 6831 standard laptop computer lithium-ion cells, giving the Tesla a seriously quick 0-97km/h acceleration time of 3.7 seconds and a range of 393 km. More than 700 Tesla roadsters have been produced. Their base price in the US is US$109,000.

Tesla Motors has also announced a Model S all-electric saloon will start production in 2011.