Given stubbornly sluggish sales, the Wii U GamePad's short battery life would seem to be among the least of the system's problems. But it is still a concern for owners, and Nintendo has announced a higher capacity battery that owners can swap out for their current one.
Nintendo's online store (via Joystiq) is selling a "high-capacity" 2,550mAh battery that lasts up to eight hours, rather than the current 3-5 hour 1,500mAh battery included in the system. It costs $32, and includes a screwdriver and instructions to replace it yourself. This is presumably the same battery we saw announced in Japan back in May.