How to calculate the starting voltage of the cooling fan?

Here is an introduction to the two voltages:
Starting voltage refers to the minimum voltage that can make the cooling fan start when the fan is suddenly energized.
The working voltage refers to the voltage of the cooling fan after the power is stable and normal operation, that is, the rated voltage.
Generally, the rated voltage of the DC fan is 12V, and the starting voltage is generally less than 7V, because the voltage provided by the system may be unstable. If the starting voltage is lower, the distance between the rated voltage and 12V is relatively large, which means that the DC fan can operate the wider voltage range, which can ensure that the low voltage can activate the starting fan when the voltage is unstable. The starting voltage value can be measured by a multimeter and other detection tools. The low operating current of the fan not only reduces the power consumption, but also reduces the heat generated by the fan motor, which can increase the service life of the fan. For oil-containing fans, it can also slow down the volatilization of lubricating oil, so the lower the current, the higher the reliability of the fan.