Internal combustion engine requires the pistons to be moved before the ignition phase of the cycle. This means that the engine must be set in motion by an external force prior to the action in which it can power itself. Based on the same principle, the First Generation motors used hand cranks to start the engine, but it was difficult, and dangerous to crankstart an engine. Although crank had overrun mechanism, when the engine started, the crank could begin to spin along with crankshaft. The person starting the engine had potential risk of injury from the crank. Additional care had to be taken to prevent back firing; with an advanced crank setting.
While the need for self starter motor was fairly obvious as early as 1899, Clyde J. Coleman applied for U.S. Patent 745,157 for an electric automobile self-starter. However, inventing motor with that could successfully work in all the conditions did not occur until 1911 when Charles F. Kettering of Dayton Engineering Laboratories invented and filed for U.S. Patent 1150523 for the first useful electric starter. This type of starter motors were first installed by Cadillac on production models in 1912. The starters also worked as generators once the engine was running, a concept that is now being revived in hybrid vehicles. The Second Generation electric starters ensured that anyone could easily start and run an internal combustion engine car.
The credit for developing Third Generation starter motor goes to Chrysler Corporation. In 1932, introduced a starter incorporating a geartrain between the motor and the driveshaft. Rolls Royce had introduced a conceptually similar starter in 1946, but Chrysler's was the first volume-production unit. The motor shaft had integrally cut teeth forming a drive gear which mesh with a larger adjacent driven gear to provide a gear reduction ratio of 3.75:1. This permitted the use of higher speed, lower current, lighter and more compact motor assembly. This starter formed the design basis or the offset gear reduction starters now employed by about half the vehicles on the road.