Article from Railway Gazette, Nov 26, 2013:
UK: Laboratory testing has confirmed that lithium iron magnesium phosphate batteries from US firm Valence Technology meet the requirements for use on the demonstration Independently-Powered Electric Multiple-Unit, which is being developed by infrastructure manager Network Rail, Bombardier and train operator Greater Anglia.
It is envisaged that overhead/battery-powered IPEMUs could operate on short, diesel-worked branch lines on otherwise electrified parts of the network. An experimental unit is being developed for trials to help determine whether any future IPEMU should be a straight battery or overhead/battery ‘hybrid’ unit.
The Valence batteries were subjected to tests simulating the conditions which would be experienced in service. These included ‘intensive’ branch line round trips with 8 h of continuous running, as well as ‘extreme’ range, speed and temperature tests.