Nintendo has detailed the battery life of the Wii U's tablet-like controller, the Wii U GamePad.
A single charge lasts up to three to five hours. To charge the controller itself, it takes two and a half hours, but users can utilize the GamePad while it's charging through an AC adaptor. Ultimately, the battery life depends on the screen's brightness.
The description Nintendo provided of the Wii U GamePad is:
The Wii U GamePad controller removes the traditional barriers between games, players and the TV by creating a second window into the video game world. It incorporates a 6.2-inch, 16:9 aspect ratio LCD touch screen, as well as traditional button controls and two analog sticks.
Inputs include a +Control Pad, L/R sticks, L/R stick buttons, A/B/X/Y buttons, L/R buttons, ZL/ZR buttons, Power button, HOME button, -/SELECT button, +/START button, and TV CONTROL button.
The GamePad also includes motion control (powered by an accelerometer, gyroscope and geomagnetic sensor), a front-facing camera, a microphone, stereo speakers, rumble features, a sensor bar, an included stylus and support for Near Field Communication (NFC) functionality. It is powered by a rechargeable lithium-ion battery and weighs approximately 1.1 pounds (500 g).
A closer look into the Wii U GamePad, as well as the console's hardware specifications via an infographic was recently unveiled by Nintendo.