It's 100% believable, technology-wise. It's a 2600 mAh LiPo (or LiFePO4 or other similar lithium battery), and the charger charges it at about 4C == 10A. The tradeoff is that such high charge rate tends to damage the battery quicker (resulting in sagging voltages/lower capacity).
I don't believe their claims that it will last 3 years of regular use, that it will have 1500 charge cycles, or that it has "novel battery chemistry". I'd give it up to a year, and even then you'd probably be experiencing much lower capacity by the end of the year, but that's my rough guess. I'm also a bit surprised that it's deemed safe for consumers and will be certified.
I don't believe their claims that it will last 3 years of regular use, that it will have 1500 charge cycles, or that it has "novel battery chemistry". I'd give it up to a year, and even then you'd probably be experiencing much lower capacity by the end of the year, but that's my rough guess. I'm also a bit surprised that it's deemed safe for consumers and will be certified.