Abstract
The Advanced Lead Acid Battery Consortium has been researching into VRLA batteries since 1992, initially for electric vehicle (EV) applications, where it achieved significant life extension in deep cycle duty. More recently it has focussed its work on hybrid electric vehicle (HEV) applications where the battery has to operate in High-Rate Partial State-of-Charge (HRPSoC) conditions. Whereas in EV operation failure occurs in the positive plate, in HEV duty, failure is due to negative plate sulfation, resulting in rapid loss of capacity. Ways of overcoming this have been investigated successfully and the ALABC is undertaking vehicle demonstration programmes to publicise this work.