Very Nice Snell.
I've been playing around with several varieties of the 18650's also.
I see some samsung 2600mah cells in your picture.
The only thing you have to be careful about is not to exceed their max discharge ability. Most regular 18650's will top out at around a 4 amp draw.
If you take a look into the cordless tools of today, you will find several high discharge varieties of the 18650. Makita uses one that can be discharged up to a 25 amp draw.
Here's a link to show you some of who's using what when it comes to power tools. I hope you enjoy it.
http://dewaltownersgroup.com/index.php/topic,204.0.html