NEW BATTERY FORMAT
As shown above, the format of the battery mounted on the SF70H has changed compared to the previous model. The 2017-spec energy store seems higher and narrower than its predecessor. The element sits below the fuel tank, a standard placement across all F1 cars.
As a reminder, the energy recovery systems (ERS) include four elements: the MGU-H, the MGU-K, the battery or energy store, as well as a pair of control boxes.
MGU stands for motor-generator unit. When acting as a generator, the device converts the mechanical and heat energy it receives into electrical energy. When operating as a motor, it is the opposite.
The current 1.6-litre V6 turbocharged power units feature two MGUs: the MGU-H (for heat) absorbs power from the turbine shaft to convert heat energy from the exhaust gases, while the MGU-K (for kinetic) recovers some of the kinetic energy dissipated under braking.
The battery stores the energy recovered and collected by both MGUs. Looking at the diagram available in Appendix 3 of the technical regulations, the energy store can feed up to 4MJ/lap to the MGU-K, which then transfers a maximum power of 120kW to the drivetrain. However, the battery can only receive 2MJ. So in order to deliver the maximum 4MJ, the energy store benefits from the contribution of the MGU-H, which serves a dual purpose: charging the battery and supplementing the MGU-K (without any restriction). The energy store is made up of many lithium-ion cells and manufacturing a battery with that kind of storage capacity in a compact, low-weight (20 to 25kg) format is a true engineering challenge. Like the engine, the device must be pre-heated since it has a narrow operating temperature window.
