Mugen Power is releasing its 6250mAh Extended Battery for the New 3DS XL. Apparently, the 3.7 volt Li-ION cell Mugen Power battery can last 3.57 times longer than the one that ships with Nintendo’s system. Mugen Power Batteries says its product will run for the following hours on a single charge: 3DS gaming: 12.5-25 hours DS gaming: 25-42 hours Sleep...