Nyko Extended battery for the 3DS: gives you moar power but........

[alfredofroylan]

Another review, seems like this thing is the real deal:

3D on, brightness maximum, wireless on:
Nyko Power Pak : 5:33
3DS battery: 2:52

3D off, brightness at minimum, Power-Saving on, wireless off:
Nyko Power Pak : 9:04*
3DS battery: 4:40

http://www.joystiq.com/2011/03/31/3ds-power-pak-review-a-battery-of-tests/