I ordered this replacement battery from Amazon advertised to fit the MyTouch 4G, which is basically the same phone as the Thunderbolt. It was advertised as an OEM battery, but it was so cheap I suspected it to be a clone; boy was I surprised when it arrived the next day (Amazon Prime is the bomb!). The battery was, in fact, a genuine HTC battery. It popped right into my Thunderbolt with one minor difference – the logo faces in, towards the screen of the phone, vs out, towards the battery cover. It is functionally perfect and the battery life is outstanding – I forgot my battery life was actually good at one time! The random resets have also vanished. All in all, this was a great buy and I might buy another for a backup; you should too!
I’ve been running Liquid ICS v1.5 MR2.7 beta since my return from Japan in early September, mostly because it was the first semi-polished Ice Cream Sandwich rom for the Thunderbolt. I like the rom a lot but the constant data drops and lack of a working camera held it back. MR3 dropped shortly after I flashed back then, but I’ve been too lazy to update. Well, I updated today and also installed the OTA radios from the official HTC ICS rom. So far the camera works (yay!!!) and it seems like the data connection is more stable. Unfortunately, trying to switch to the front camera permanently breaks the built-in camera app. I have also learned that my factory battery is dying. Lately I’ve been getting random resets (no surprise there) but the phone has been powering back on with a nearly dead battery. I thought it was a fluke, but no, the battery really is going south so I ordered another from Amazon.