Those are Chinese generic batteries that are available on eBay and elsewhere. I had a set and charger for the Captivate, purchased for less than half what that seller is asking. They did work, but nowhere near as well as the OEM battery despite having the same nominal capacity rating. The charger was also really weak at 300mA? or so and took hours to charge (USB is 500mA). They were good when I needed a few extra hours in a pinch, but that's about it.
Swapping batteries also can throw your battery stats off.
I have no experience with the USB boot loops etc.
Samsung AT&T Galaxy S III I-747
If you have an Android phone and aren't using DROPBOX
, then why the heck aren't you? Even the free plan is EXCELLENT.