I agree with Stosh. That model of battery has a low amp rating of 6.8 amps continuous discharge rate. Depending upon what resistance build you are using on your mechanical mod, the NCR18650B may or may not be adequate for your application.
If using normal resistance coils (1.2 ohm or higher), that battery is fine. If using sub-ohm build coils, you need a high-drain IMR battery with at least 20 amp continuous rating. Click on the "blog entries" under my avatar for my "Battery Basics for Mods: IMR or ICR" article for a large list of recommended IMR and IMR/hybrid batteries that cover a wider range of applications.