Reddit reviews Hyperion Samsung Galaxy Note II 6200mAh Extended Battery + Titanium Grey Back Cover (Compatible with Samsung Galaxy Note II GT-N7100, T-Mobile Galaxy Note II SGH-T889, Sprint Galaxy Note 2 SPH-L900, At&t Samsung Galaxy Note II SGH-i317, and Verizon SCH-i605)
We found 1 Reddit comments about Hyperion Samsung Galaxy Note II 6200mAh Extended Battery + Titanium Grey Back Cover (Compatible with Samsung Galaxy Note II GT-N7100, T-Mobile Galaxy Note II SGH-T889, Sprint Galaxy Note 2 SPH-L900, At&t Samsung Galaxy Note II SGH-i317, and Verizon SCH-i605). Here are the top ones, ranked by their Reddit score.
I got mine from Amazon (with Prime) and I think it's 23 dollars there if you have Prime as well!
http://www.amazon.com/gp/product/B00A6U0N56/ref=oh_details_o02_s00_i01?ie=UTF8&psc=1
I'm not sure if the price changes without it, but if it is then there are plenty of other solid batteries out there. Always check the reviews before you jump the gun, but these things won't make your battery blow :)