Safely ground your robot's metal frame with this Resistive Grounding Strap. This strap has a built in 470Ω resistor to prevent high-current discharges while still minimizing the difference in charge between the robot electronics and the frame.
Simply plug the XT30 end of the grounding strap into a free XT30 port on your robot and attach the ring-terminal end to a metal part of your frame using a nut and bolt.