In hybrid electric vehicles (HEV's) the requirements on batteries for energy storage are completely different from those in battery powered electric vehicles (BEV's). In order to come to a succesful development of HEV's, beside fullfilling the technical requirements, the battery has to have a long life time and must be cost effective. On the basis of TNO technology (patent pending), the development of a bipolar lead-acid battery has been started, together with a battery manufacturer (Centurion), having as final aim a commercial battery for hybrid vehicles and other high power applications. A prototype of 80 V has been built and tested, mainly for the purpose to identify the route to the final aim. Results of this prototype are discussed