Hi folks, new user here. A buddy and I along with our sons, are planning on building an electric go-kart using a car starter for the motor. I have several questions as I haven't been able to locate a simple circuit for safe motor control. One option is to try and build a PWM speed control circuit but since neither one of us is an electrical engineer I would worry about what I wouldn't know about the limitations of the circuit. Option 2 is what I would like to inquire about. I seems to me that if you could set up a system where say three 6v deep cycle batteries are in a series circuit controlled by some sort of 4 position switch (off, 1 battery connected, 2 batteries connected, 3 batteries) then you could use the natural cranking amp capabilites of the batteries to control speed. Does anyone have any comments, suggestions, or especially particular batteries, motors, and/or switches to use?