After you press button?? A on Wii controller, power indicator only bright 1 piece or 2pcs blue light, indicate that power supply not enough, must charge it.
One side of USB cable plug to battery pack, another side plug to Wii console, then can charge for this item independently.
Indicator light is red when charging, blue when full, charge item <6 hours.
It's able to use after inserting fully charged battery pack into controllerslot, if need compatible with Wii console code, directly using battery pack code is ok.