[sevin7]

Looks like a scam. If the battery can fit under the stock cover, than it can't possibly be physically larger than the stock battery (unless they made it a tad bit thicker... but there is presumably a good reason why HTC's engineers didn't do that) . The extended Seidio battery and the stock battery are both lithium ion batteries, so they have the same energy density.

Battery makers love to over rate the capacity of their batteries, but the truth is two batteries using the same chemical composition of the same size, will have almost identical power capacities. Unless of course one of the batteries is very poorly made, which is not case the case with the stock TP2 battery.

EDIT: Just read the other posts about this battery. To the people who are buying it: Conduct a controlled experiment with the stock battery and the new one, and I bet you won't find much of a difference.