Nothing wrong with rechargeable in general, but you gotta be careful with battery chemistry, lithium or Lions are among the most powerful ones and the ones you gotta be real careful with.

Eneloops are among the most trusted brand of NIHM rechargeable batteries, nothing wrong with Energizer or duracells NIHM's though. The most important part is that you get a smart charger to go with your rechargeable batteries. Alkaline cells are not that good on powerful flashlights.

I use this one since it only cost me $12, but it's an australian version and comes with an australian prong. It does include an adapter for use with american style wall outlets.

http://www.amazon.com/Duracell-Charg..._sim_sbs_hpc_2

this is the more expensive american version that comes with the right prong for american outlets and doesn't require an adapter.

http://www.amazon.com/Duracell-Charg...cr_dp_asin_lnk

The charger I use is pretty nice since it lets you charge other devices (iphone, tablets, etc.) using AA/AAA batteries through a USB port.

BTW check out "Nlee the engineer" reviews in amazon if you need to find quality batteries or chargers, he usually has very informative reviews

You can also buy chargers that display voltages and can recondition AA/AAA batteries. Maha and La Crosse are the two most popular brands for that.

here's a review for your light and some beam shots on both 3x AA and 26650 batteries. scroll down for the beam shots
http://budgetlightforum.com/node/8803