Range

How far can pure electric cars go on a single charge?

By Gavin Conway on July 20, 2011 4:36 PM

Range varies between electric vehicles depending on the size of batteries and the car they are powering, as well as the road conditions and driving style.

Conventional family-car size vehicles - typified by the Nissan LEAF - coming to market over the next couple of years claim a range of around 100 miles under 'normal' conditions, with charging taking about eight hours on a regular household socket. For many urban commuters, this will be more than enough for daily use.

Smaller EVs such as the G-Wiz and upcoming Renault Twizy are not classified as passenger cars. These so-called quadricycles are meant strictly for urban motoring. Their batteries are much smaller than those of EVs such as the Leaf, and range is consequently much lower - the basic G-Wiz can manage a claimed 48 miles on a charge and the Twizy 60.

There are, though, vehicles capable of much higher range. EV manufacturer Tesla, for example, claims a 245-mile range for its Roadster Sport pure electric sportscar (based on the European Electric Vehicle Combined Cycle).

How will weather affect range?

Very cold or very hot weather will degrade battery performance, which will reduce the range available. Batteries are happiest when operating between 20 and about 40 degrees centigrade, so some new EVs regulate battery temperature. The ones that don't do this will suffer in extreme cold or hot, but UK weather is mild and won't impact on range significantly.

Heating the interior can be a huge drain on the battery with consequent knock-on effect on range. Obviously, other systems such as headlights and windscreen wipers will also be a drain, but not nearly as much as heater use. Put the heating on full blast and you can expect rage to drop by up to one third. Vauxhall recommends heating the cabin of its Ampera using the heated seats rather than the climate control system whenever appropriate, as this reduces the drain on the battery.

Likewise, very hot weather - and using the air conditioner - will accelerate battery drain and negatively affect range.

What about driving style?

How you drive will also have a significant impact on how far you’ll get on a charge. The more aggressive you are with the throttle and brakes, the worse it will be for range. The best approach is to anticipate traffic flow and cruise without aggressive braking and accelerating. Most EVs can also recapture energy lost as you slow down, and gentle, sustained deceleration helps improves range more than hard braking.

Motorway, rural and inner city driving

As well as driving style, the types of road you're driving will affect range. Motorways eat battery while cities are an electric vehicle's best friend, but what is the exact impact?

TheChargingPoint.com's Michael Boxwell took out a Mitsubishi i-MiEV, with an official claimed range of up to 92 miles, to get some real-world figures:

1. The motorway test
"I drove the Mitsubishi at the legal limit during a Thursday evening rush hour on the M45 and M1 motorways. Traffic was busy, but congestion was low, allowing me to cruise at the legal limit for most of the time. Headlights were used for the entire trip and the radio and heated driver’s seat were used for part of the journey. Average speed for the entire trip was 63mph with the car cruising at 70mph for the majority of the journey."
Range Achieved: 53.7 miles

2. The cross country test
"The Mitsubishi was driven on a combination of urban roads. There was a fair amount of traffic, but an average speed of 44mph was achieved. The high torque on the car meant we could easily overtake other vehicles where necessary."
Range achieved: 64.4 miles

3. Inner city driving
"I drove the Mitsubishi through the busiest and most congested roads, achieving an average speed of 18.6mph – slightly higher than the average car speed in London. The test started during the evening rush hour and headlights were used for the entire journey. Satellite navigation and radio were also used, as was the driver’s heated seat where necessary. This was by far the longest test I carried out in the car: from a completely full battery to flat took virtually five hours of constant city driving."
Range Achieved: 92.7 miles

Mike's conclusion:
"If most of your driving is inner city, then it is possible to achieve the range that Mitsubishi claim for their car, although probably not in the depths of winter. Drive faster, or use the air conditioning or fan heater and the range drops significantly. If you need an electric car that can do 92 miles in any condition, the Mitsubishi – or any other current mass-produced electric car for that matter – simply won’t do it. My personal recommendation is to halve the official range to give you a safe, practical range and anxiety-free driving whatever the conditions.

"Yet if your daily journeys are within the range of an electric car, they’re a lot more convenient than a petrol or diesel car. No more driving to a service station. No more wasting time refuelling your car. Just plug your car in when you get home each evening and the next day you have a full tank of electricity. It’s that simple."