Question to the Department for Transport:

To ask the Secretary of State for Transport, what research his Department has (a) commissioned and (b) undertaken to assess the reduction of battery capacity of electric vehicles as a result of regular recharging.

Research into battery technologies is being led by the £274m Faraday Battery Challenge which is funded through the Industrial Strategy Challenge Fund. As part of this, the University of Cambridge (with eight other university and 10 industry partners) is leading a project on battery degradation, examining how environmental and internal battery stresses, including charging and discharging rates, damage electric vehicle batteries over time.

Alongside this, the Office for Low Emission Vehicles is currently funding a £30m competition looking at Vehicle to Grid technologies. Many of the projects in this competition are also collecting data on battery usage and capacity.