General Motors may allow buyers of its Chevy Volt electric car to rent the vehicle’s battery as a way of pricing the vehicle at a comparable level to a traditional, petrol-driven family saloon.

The Volt is emerging as one of the most crucial vehicles in GM’s history. Failure would be a deep embarrassment after the fanfare surrounding its development. But success could propel GM past Toyota as a pioneer in alternative energy vehicles. GM has assigned 150 engineers to the project.