unknown electrical issue

[ryaneogilvie]

We run a 8 motor drivetrain (6cim 2minicim) and this happens whenever our battery is low (Which can easily happen after 3min hard defense). I don't believe it is any problem with your robot or wiring, instead the battery at low levels is simply unable to provide enough current for 4 cims to run at full from stop, especially when turning and running a compressor. When you attempt to draw to much current from a low battery, the voltage can drop so low that your robot stops running commands. (I believe the minimum is around 5 volts). The constant starting and stopping is due to the motors drawing to much current, losing control because of low voltage, stopping, regaining control, then repeating. If you just try slowly accelerating you should be fine, but you should just change battery.
watch the driver station - if your ever dropping below 5 volts you're probably at low battery. (or you're stalling motors, inefficient drive base, etc...)
It's unlikely because you mentioned it happening after 3min of hard defense, but this can also happen because of communication interference when to many wifi networks are present. You'll see the robot enable and disable erratically on the driver station. In this case one fix is to switch to 5ghz wifi.
hope this helps.