Utility San Diego Gas & Electric in the US is planning to use a mobile car-charging device for plug-in electric vehicles in the region.

The charger will allow people to charge cars anywhere in San Diego and allow the scheduling of car charging to make use of off-peak rates.

The device allows people to view data such as the amount of kilowatt-hours used and carbon emissions via the internet or a mobile phone when used with a smart metre, with the driver’s usage being billed to their account.

The device will help drivers charge electric cars when there is a lack of public charging stations.

The device, Plug Smart “intelligent charger”, has been developed by US-based Juice Technologies.

It will be installed in five cities including San Diego, as part of the US Department of Energy’s battery funding project to set up the network of charging stations for nearly 1,000 all-electric cars.

The cars, Nissan Leaf sedans, will undergo trial next year.