This has been known since before Wii U was launched even - I think. It baffled me then, it does now.
It's also ironic that this larger battery launched in Japan first, and there had been no word of it coming to the West, so after a long while I imported one, which wasn't cheap. Then about a week later Nintendo announced they were bringing it West, and a lot cheaper than what I paid for it, of course. T_T
Nintendo Network ID: Cheebee 3DS Code: 2320 - 6113 - 9046