Have you tried to resync it. I found this
1. Press the Power button on the Wii console to turn it on.
2. Remove the battery cover on the back of the Wii Remote you wish to sync up, and open the SD Card Slot cover on the front of the Wii console. (The SD Card Slot is the small door located near the disc drive slot.)
3. Press and release the SYNC button just below the batteries on the Wii Remote; the Player LED will blink. Quickly press and release the SYNC button on the inside of the SD Card compartment on the console.
4. When the Player LED blinking stops, the syncing is complete. The LED that is illuminated indicates the player number (1 through 4).