Without a properly designed power management unit, power failures are to be expected on systems raining on batteries. Unfortunately, there is no low cost fully configurable unit that is available on the market for small mobile robots. This paper presents the design of a power management unit for a six legged pneumatic robot that runs at a top speed of 1.11 m/s. The system consists of a main unit that acts as a fast charger, a power supply and a monitor of the energy left available to the robot. This unit communicates with small circuit embedded on each NiMH battery, which gives their level and stores the battery's parameters so that the charger can adapt its charging algorithm to batteries of different capacity or chemistry. Furthermore, this power management unfit takes advantage of the controller area network (CAN) and the PIC18F brain to act as a monitoring, fully configurable, remotely controllable and autonomous node.