1. battery: used to store electric energy, usually lead storage battery, and the electrolyte is dilute sulfuric acid.

2, brake fluid: it is the usual brake oil. At present, automobile braking is generally hydraulic, that is, brake fluid is used as the medium to transfer the force of the brake pedal to the brake disc.

3. Ignition coil: low voltage is converted into high voltage, and the spark generated by the spark plug below ignites the oil-gas mixture to do work.