First thing I noticed was the Robot getting a bit more random than usual, then the backlight of the LCD on the QuakeZure stand alone demo kit stopped working. Using a multimeter I found that straight off the charger the batteries were 1.4v which then rapidly fell to the 1.2V as per the label (should have paid more attention to the label).

The batteries also do get quite hot charging.

The Magician chassis comes with a 4 x AA battery holder so the Netduino (or LCD display) was getting less than 5V under load and was browning out.

Hence the upgrade to the 6xAA battery pack for the robot. The SeeedStudio motor shield has a 5V regulator on board to ensure the Netduino isn’t fried.