Voltage Drop -- Slowdown of motors

[X-Istence]

Hello,

My team is using three motors, and several other things on the robot, and we are afraid that after the battery is drained, or down to a certain voltage that we won't be able to keep our shooter wheel going at a constant speed for us to shoot.

Now, my mentor suggested we crank up the PWM's more as the current drops by having a geartooth sensor check the speed of the wheel, and once it drops we crank the PWM's.

Will this work? Or will we accomplish nothing, and once the battery is drained it is basically a lost cause anyways, and it is not needed anymore at all.