1.  The vans are powered by conventional lead acid batteries, recharged by plugging into mains electricity or parking over an induction loop overnight.

2.  It is based on fuel cell technology, which, like conventional batteries, uses electrochemical reactions to generate power.

3.  The nickel hydride battery is made of environmentally safe materials and holds a charge longer than conventional lead acid batteries.

4.  In addition, his balloon had a multi-channel radio, transponder and a solar panel to back up its conventional battery power.

5.  The only zero-emission cars that are close to mass production are powered by electricity that is stored by conventional batteries.

6.  The only zero-emission cars that are close to mass production are powered by electricity stored by conventional batteries.

7.  Their equipment included conventional battery power with a back-up solar power system.