You can get 3 generic batteries and a wall charger on ebay for around $10-12 shipped. They say they will work in the mytouch 4g or the TB. I used the same batteries made for my retired Facinate & Incredible and they work great. They will not charge in the Facinate though. They did however in the Incredible. I believe they are the same mah / power as the standard TB battery. It's worth the $ either way.
Sorry but the TB has a 1400mah batt. where the Dinc has a 1300MAH, this does not matter because the Dinc Batt. is a completely different sice then the Tbolt's.
so that solution wont work.
seidio has a 1600mah that fits the Tbolt with no exteneded door and HTC is coming out with a 2500mah *maybe 2700 im unsure of the MAH that will come with the extened door cover.