I believe the highest capacity 18650 Li-ion cells are now only 3600 Mah. Panasonic NCR 18650b were the standard and are 3400 Mah. All sorts of other cells, especially those with 'fire' in their names, are likely 18650 cells taken out of laptop batteries with a new shiny wrapper wrapper and some fancy marketing.
They like to claim to have protection circuitry too when none exists. I believe I own such a reclaimed laptop cell, and it lasts about 1/4 the time in my Nitecore HC50 as do my Orbitronics 18650's which are based on the Panasonic NCR18650B cell. I have two bare panasonic cells too.
It'll be nice when prices drop.
http://www.amazon.com/Battery-Tender-BTL14A240C-Lithium-Phosphate/dp/B00F9LPJ8S/ref=pd_sbs_auto_2?ie=UTF8&refRID=0K6Z43NQVDAD9J45EBEA
