Of course there are Monster Hunter 4 mobile batteries ⊟
I guess this is for when you want to get more Monhun in than your 3DS battery will allow. These rechargeable battery packs can be used with 3DS, Vita, and phones, and have lovely custom charge meters. And poogies and Felynes and what have you.
Play-Asia is out of the logo batteries, but has the green, yellow, and blue varieties for $54.90 each.
BUY: Monster Hunter 3 Ultimate for 3DS/Wii U, upcoming games