I was trying to test the capacity of a battery pack I'm building and was trying to measure the current draw using a 35 turn 540 brushed DC motor (the website I had purchased from said something about it being sensored, but I couldn't find any sort of sensor inside.) I read somewhere that the cuts/notched are related to some sensor.
I connected the DC 540 motor to a 1.2V 7000mAh NiCd battery and measured the current. In one direction it spins a bit faster and reads 1.58A and in other direction it spins a bit slower and draws 1.89A. Any idea what could be causing this?
Both the carbon brushes seem so have even wear on them, too.