Mention electric vehicle and it probably won’t be long before the phrase ‘range anxiety’ enters the discussion.
With battery technology currently allowing an electric vehicle a maximum range of about 100 miles before recharging, the concept might be suitable for low-mileage fleets, but the compromise is obvious.
Hybrid pioneer Toyota has decided to diversify with plug-in versions of the Prius – while planning to introduce a full electric vehicle in 2012.
The principle of a plug-in hybrid is that the car runs on the battery for a short period, while the engine takes over when the range has expired. Vauxhall is planning to leapfrog some of its rivals with a new family car to be launched in 2012 using unique technology.
The Ampera uses an electric motor and has a battery that is charged in three hours by plugging into a standard 240-volt electricity supply.
Vauxhall’s research found that, for as many as 80% of people, their typical driving in a day covers no more than 30 miles, so the battery in the Ampera has a range of 40 miles.
That might seem short compared with the claimed 100 miles of the latest electric vehicles.
However, the Vauxhall also comes with a 1.4-litre petrol engine. But the engine never drives the car directly. When the battery is depleted, the engine takes on charging duties for the battery as it continues to power the electric motor. If necessary, it allows the Ampera to cover a further 310 miles on a full tank of fuel.
The engine never fully replenishes the battery. This is done more cheaply by plugging the car in.
But it does address concerns about range.
After a single three-hour charge, the Ampera can run, if necessary, for up to 350 miles, and then could continue after refuelling rather than recharging.
The Ampera is based on the same platform as the Vauxhall Astra and Chevrolet Cruze, will seat four people, has a full-size boot, will accelerate from 0-60mph in about nine seconds and is capable of reaching 100mph.
When the battery range is expired, the engine cuts in seamlessly with no change in performance because the motor continues to drive the wheels.
In the prototype the engine note was perceptible – although Vauxhall says production versions will be even quieter – but it was bizarre how it didn’t seem directly related to the car’s performance.
The car accelerates smoothly regardless of where the energy was coming from. Like a hybrid, the Ampera’s battery is also recharged when braking.
In its range-extending mode, with the engine charging the battery, Vauxhall claims CO2 emissions are less than 40g/km. Equivalent, it says, to 175mpg.
However, we were also told that the fuel tank would be somewhere between eight to 10 gallons, so its fuelled range of 310 miles would seem, at best, to equate to about 39mpg. Maybe this will become clearer before the car’s launch.
A clever feature looks after the engine and reminds the driver if the car has relied solely on plug-in battery power for a while.
As it’s a conventional engine that needs running and lubricating occasionally, the car has been programmed to ask to run the engine.
Likewise, if it detects the fuel is ageing and would have an impact on the engine’s performance.
The battery will charge to a maximum of 80% capacity and will deplete to 30% of capacity before the engine takes over charging it.
Vauxhall says this improves the life of the lithium ion battery as over-charging it or running to flat hampers performance.
As a result, Vauxhall says it will be able to offer a 10-year warranty on the battery and expects a usable battery life of at least that time.
Vauxhall expects a price tag of about £30,000 for the Ampera, before any possible Government subsidy to encourage take-up of ultra-low CO2 vehicles.
The Ampera offers a more user-friendly EV alternative although does not end our reliance on fossil fuels.
It won’t be cheap, but ends worries about range and offers performance and practicality.