Somehow managed to fit a 10,000mAh battery inside of my Wii U game pad! Battery life from around 2 hours to (so far) more than 13 hours at full brightness. See captions,
Golden Power PX27 Alkaline 6 Volt Battery - Batteries for Photo
Baterie camera LP-E8 Canon EOS Rebel T2i, T3i, T4i, T5i, EOS 600D, 550D, 650D, 700D, Kiss X5, X4, X6 7.4V 750mAh - Celo