The second-generation Formula E car introduced for the 2018–19 season had a 54 kWh battery.
The Spark SRT05e, commonly called the Gen2 car, replaced Formula E’s original first-generation car. Its larger battery allowed drivers to complete a full race without changing cars midway through the event, ending the mandatory pit-stop car swap used in the early seasons.
The battery was developed by McLaren Applied, while Spark Racing Technology supplied the chassis. The car also introduced the distinctive halo cockpit-protection device and substantially higher performance than the first-generation machine.
The 54-kWh figure describes the usable race-energy storage specification commonly given for the Gen2 battery. It should not be confused with the energy limits imposed during individual races, which could vary with regulations and race conditions.