okay I visited the link then googled the light and found the Amazon page for it. For max AAA performance you want Energizer Ultimate Lithium AAA's. These AAA cells have above NiMH capacity and give a full 1.5volts per cell until they die. The sleeve included is meant for an 18650 cell. According to what info I have found this light takes AAA or 18650 cells ONLY. Do not risk blowing your light with CR/RCR cells. A high mah 18650 would be the way I would go as it would last the longest and is rechargeable. Any current 3400mah 18650 such as Orbtronic,Keeppower,Olight,Eagletac 3400mah cell should be fine. Avoid flat top cells make sure the 18650 you get is button top. Did you get the package that comes with the little charger? As cheap as this light is you can get and compare both 18650 and Energizer Ultimate Lithium AAA cells and still come out under 30 bucks.
Lastly, there is NO way this light puts out 2000 lumens. Ive seen and read of this light before and the best you will possibly get is maybe 500 lumens no matter the power source you use. Pretty cool its variable focus and I know this light sells very well and should serve you well. Just dont cheap out on the batteries. There are indeed rechargeable AAA NiMHs out there (Duracell Ion Core) that are excellent and are re wrapped Eneloops. But for the most "kick" the AAA Energizer Ultimate Lithium Ions are what you want. If you go the rechargeable route get a good charger like a Nitecore d4 or better yet Xtar VC4. Either charger costs 2x what the light did but if you want the most reliable multi chem chargers those 2 are the way to go.
The Energizer Ultimate Lithium AAA's may give the most kick but also will not last as long as rechargeables. So there are your 3 choices its all how much do you want to spend. The Energizer Ultimate Lithium AAA's will get expensive after awhile as where I am they go for 12 bucks a 4 pack. Personally Id get any of the 3400mah 18650s listed above. Good luck and keep us posted.
