BMW is giving its all-electric i3 hatchback a boost with a new battery pack which doubles its range to almost 200 miles.

The uprated battery will be available on i3 models from July and will be fitted to both the pure electric car and the petrol/electric range extender version.

With the benefit of the Government grant of £4,500 for low emission vehicles prices for the new i3 start from £27,830 and £30,980 for the range extender - an increase of some £2,000 over the original model which was introduced in 2013.

The new lithium ion battery is rated at 33kWh and has almost 50 per cent more capacity which not only increases the range on a single charge but also keeps the car's lively performance with a 0 to 60 time of 7.3 seconds.

In the range extender, which is fitted with a 647cc two-cylinder petrol engine to generate more power, it also reduces CO2 emissions to 12g/km - the equivalent of 470.8mpg from a diesel car.

The new versions of the i3 are also fitted with rapid chargers which now take only three hours for a full charge.

BMW says that the new battery is the same size as before allowing the car to retain its boot capacity of 260 litres, extending to 1,100 litres with the rear seats folded, and the i3 will now be available in the blue and grey colour scheme which had been exclusive to the i8 plug-in supercar.