스타터 모터 교환 수리 사례

2026. 6. 30. 작업

난이도 & 준비물

증상

Why do car starter motors draw so much current?

처리 내용

All electric motors consume more current at startup compared to steady state. Check out the label on your fridge for example (or look at this one ): the max current on the label is 2-3 times higher than the value you'd obtain from power to voltage ratio. The reason behind this lies in the properties of electric motors. Approximately, such motors have torque proportional to the current and speed proportional to voltage. When the motor starts, you need much more torque to get it running than you'd need in steady state to keep it running. Hence you need more current. By the way, a lot of cars have even more powerful starters (e.g. a Landcruiser has a 2.5 kW one). That's over 200 A in steady state. Multiply that by 2 or 3 to get the startup current, and you'll get around 500 A that the battery must be able to provide.