Power and performance: the Formula E battery

The battery is the car, according to Gary Ekerold, operations manager at Williams Advanced Engineering and head of the programme to design the battery for the Formula E electric racing series. It’s a comment that is difficult to grasp until you see the battery itself.

It is a huge trapezoidal lump, wrapped in carbon-fibre composite and studded with hoses and anchoring points; much larger even than a Formula One engine. The driver’s monocoque safety cell bolts onto one face, and the inverter, motor pack and rear suspension assemblies onto the opposite side, making it a major structural part of the car in a way unique to electric vehicles. When we normally talk about structural batteries we’re referring to bodywork materials that can store electrical energy; we’re not talking about things that actually hold the car together and take the bending moments, stresses and forces generated by the car’s interaction with the road — especially not at racing speeds.