I got my eGo LR Mega atty (cylinder/"type B") from goodprophets.com. I bought 2. One is for backup, though my primary one is still going strong after a month of constant vaping. I can't say for sure whether the USB 650 battery gives it a harder hit compared to a standard 650 eGo battery since I only have the USB one, but using it as a PT pretty much provides an endless vaping session.