I bought my Wii Fit for the Christmas holiday and I have been getting a surprisingly fun workout. I have found that every so often, especially while stepping on the board, the Wii Fit would get disconnected and I get the message “Communication has been lost, hit “A” and power button on the board”. I changed the batteries but that did not help. I did a little research and found some interesting clues to why it might be happening. I had a theory. Since the batteries are at the bottom of the board I thought the vibration of stepping plus the pull of gravity might be loosening the battery connections enough for the board to lose power temporarily. To test my theory I made a shim out of cardboard from a cereal box to hold the batteries firmly in place. This seemed to have done the trick since I have not had the problem since.
Print out the template and trace the pattern on a piece of thin cardboard from a cereal box or shoe box. Cut out the darken shapes on the template. Place the cardboard on the battery cover. The tabs on the Wii Fit battery cover should fit through slots cut out of the template. I used 2 pieces of cardboard to hold the batteries snugly in place. You can use a piece of tape to hold the cardboard in place.