Yes, I think you are right, I was thinking of putting the battery box to the motors direct and not through the drive, we did that years ago when we wanted to move large machines but had no power but they were DC motors.
So, about that feed hold, I know why it slows the motors to a stop, that's because you guys use stepper motors and you could loose a step right. I should try to remove the feed hold and rename the stop.
Ray.