Energy store or ES in F1 cars is a set of lithium-ion batteries that stores energy from the ERS and the powertrain. ES primarily delivers energy to the MGU-K and MGU-H. The battery also takes energy from MGU-K and MGU-H as well. 

MGU- K is motor generator unit – kinetic and MGU-H is motor generator unit heat. ES is part of a hybrid F1 car and the kinetic energy recovery system (KERS) and the hybrid power unit (HPU). 

These systems use energy from the car’s brakes and exhaust to charge the battery, which can then be released to power the car’s electric motor and improve performance. 

Additionally, some teams use flywheel-based energy storage systems to store and release energy during the race. These systems use a spinning flywheel to store energy, which can then be released to power the car’s electric motor.