Volvo has joined eight other European companies to develop car body panels that double as rechargeable batteries.The development of hybrids and electric cars is often dragged down by the size, weight and cost of batteries, but a few European companies are navigating their way around this dilemma. Tests are currently being conducted that sees a composite blend of carbon fibre and polymer resin being developed that can store and charge energy faster than conventional batteries. And because this material is strong and pliable, it could very well be used in the building of car body panels, the companies have said.Volvo estimates a range up to 130km when the car's doors, roof and bonnet are replaced by this new material rather than steel. A car’s weight could be chopped by as much as 15%, too."Our role is to contribute expertise on how this technology can be integrated in the future and to input ideas about the advantages and disadvantages in terms of cost and user-friendliness," says Per-Ivar Sellergren, development engineer at the Volvo Cars Materials Centre.Initially, the car's spare wheel recess will be converted into a composite battery."This is a relatively large structure that is easy to replace. Not sufficiently large to power the entire car, but enough to switch the engine off and on when the car is at a standstill, for instance at traffic lights," says Per-Ivar Sellergren.But the application of this material, should the project be successful, is not limited to car body panels. Slimmer cell phones and laptops that require less frequent charging are a few things we could look forward to.