According to online retail stores Gamestop ad Amazon, the Wii U Pro Controller can last up to 80 hours on a single charge.
The claim is amidst the product description on both stores, which also makes mention of the fact the pad is incompatible with Wii games.
"Your games, your way," the official blurb states. "However you think of your gaming style - hardcore, old school, or purely nostalgic - the Wii U Pro Controller puts you in the game. Designed for accessibility and extended gameplay comfort, the Wii U Pro Controller features the dual analogue sticks and ergonomic button layout that you've come to expect, as well as a rechargeable battery that can last up to 80 hours on a single charge.
"The Wii U Pro Controller can be used for playing a variety of games - from packaged games at retail to downloadable games from the Nintendo eShop. Look on the back of Wii U game packaging to see which games use the Wii U Pro Controller. Not compatible with the Wii system or games."
It seems the Wii U GamePad (that’s the big one with the screen) lasts 5 hours.
The Wii U Pro controller is listed on Amazon for $49.99 and also comes with the Wii U ZombiU Premium Pack, though that’s currently only been announced in Europe.