What Is Jump Start?

A jump start is a colloquial term for a method of starting an automobile or other internal combustion engine-powered vehicle having a discharged battery.

Most passenger vehicles use a standard 12-volt direct current (DC) Lead-acid battery which, when the driver turns the ignition key, an electric motor engages the teeth on the flywheel, briefly turning the flywheel which is connected to the crankshaft and powers the spark plugs until ignition is achieved and the engine can produce its own electrical power from its generator or alternator.

When a battery fails or is discharged, such as by inadvertently leaving one’s headlights switched on while parked, the car’s engine will not “turn over” when the ignition key is turned. Many motorists carry “jumper cables” which consist of a pair of heavy gauge wires with large crocodile clips at each end.