I opened up my controller today expecting to find a 3DS (CTR-003) style battery, but instead found a blue plastic encased battery pack with a plug that goes into the controller board itself. To unplug it I need to open the entire controller, not just the battery compartment. I haven't seen any evidence of this blue battery online. This controller came inside an official Nintendo WiiU Deluxe Bundle. Any idea if I can replace this? And if so, with what product? The blue plastic has no writing on it at all.