Don't you hate it when your Wii Balance Board runs out of battery in the middle of the game? Now you can say goodbye to those expensive alkaline batteries with the Wii Fit Power Pack. With the Wii Fit Power Pack, you can play continuously on the Wii Balance Board for up to twenty hours with one charge, and easily recharge the Power Pack with the included USB cable on your Wii system or any USB ports. Don't let dead batteries keep you from working out at home.