A hybrid car combines an internal combustion engine with an electric motor and batteries. There are three main hybrid drivetrain designs: series, parallel, and series-parallel. A series hybrid is powered solely by the electric motor, while a parallel hybrid uses both the engine and motor. A series-parallel hybrid can switch between the two. The car's electrical system has a high-voltage system for propulsion and a low-voltage system for safety and controls. The high-voltage system includes the motor, controller, and lithium-ion battery packs. The low-voltage system operates safety devices like the shutdown buttons and brake sensors that cut power if issues arise. The shutdown circuit uses relays and switches to isolate the high-