Startmotorbelasting

Startmotorbelasting, in automotive engineering, describes the load encountered by a starter motor during the cranking phase to start an internal combustion engine. The load is the combination of electrical demand from the battery and the mechanical resistance of the engine, including compression, friction and inertia of rotating parts. The starter must deliver sufficient torque to bring the engine up to a stable cranking speed.

Electrical load is the current drawn from the battery by the starter windings. On 12-volt systems, starting currents commonly range from about 100 to 350 A for many gasoline engines, with higher values for diesel engines or cold starts. In demanding conditions, current can rise toward several hundred amperes. The effective load depends on battery voltage, cable resistance, and winding resistance, and it increases when voltage sags or the temperature is low.

Mechanical load consists of the torque required to overcome engine compression and internal friction, plus the inertia of the crankshaft and connected components. This torque requirement varies with engine size, condition, lubrication and temperature. Higher compression, poor lubrication, or cold engines raise the mechanical load and demand a greater starting torque from the motor.

Measurements and ratings for startmotorbelasting are expressed through specifications such as cold-cranking amps (CCA) or cranking amps, and the motor’s nominal torque. Start events typically last a fraction of a second to about one second, and the starting speed is usually a few hundred revolutions per minute.

Excessive startmotorbelasting can cause voltage drops, battery strain, overheating or premature wear. Design and maintenance responses include ensuring adequate battery capacity and wiring, selecting a suitable starter (often with gear reduction or higher torque), and employing systems such as start-stop or preheating to reduce peak load.