Review on Rechargeable Battery Packs and Charger for Wii & Wii U Remote Controllers, Motion Plus Controllers (Dual Charging Station Dock + 2 Pack 2800mAh Wii Replacement Batteries + USB Cable) by Ben Karlen

Aside from the difficulty of reloading these packs, they run out after a few days. If you do manage to charge these packs, use them immediately because after just a day of sitting, they went from what seemed like a full charge to a bar and had to be recharged. If I were you I would find other packages or risk you. maybe you can get a good one I didn't know exactly.