For a project I need to switch on a simple handheld vacuum cleaner with an Arduino. I am thinking of using a relay or mosfet. I opened the case and a 7.4 V 2200 mAh Li-Ion battery powers the motor, through a regular switch.
On the manufacturer's website, the power of this vacuum cleaner is 120 W, so according to my understanding:
I = P/V
I = 120 W / 7.4 V = 16.2 A
So according Ohm's law, the resistance of the motor has to be 0.46 Ohm right? Isn't this too low?