We get a lot of questions regarding batteries, which batteries to use, and where to buy them. Here is a short reply I often give, regarding products that use C or D batteries:

I use D NIMH batteries, 12,000mAh, made by CTA. I use C NIMH batteries, 6,000mAh, made by Accupower. I buy them at Thomas Distributing . As far as I know these are the highest capacity available.

I use a Maha MH-C808M smart charter, which will charge AAA, AA, C, D size NIMH batteries. Any smart charger will work, and prices vary. Ansmann also makes good chargers. Do not buy a cheapy charger as they use timer technology and will not adequately charge the batteries, and also will take forever and a day to charge them. The same web site sells this charger, or, you can search the web to search for better pricing.

Any NIMH battery will work.

Alkaline batteries will work but be about 1/2 as bright, in the high power application flashlights, like the drop-ins, Ultra-Throw, etc.

Regarding the 18650 Li-Ion rechargable batteries, a brand called 'AW' seems to have the best available, and these can be found here: www.lighthound.com At the bottom of the page is listed a good charger for the 18650 battery. I strongly suggest that only protected 18650 batteries be used.