Jak Crow
Contributor
Be careful with Trustfire, or anything with *fire in the name. They're more often than not cheap cells with overstated power ratings. I bought a set that claimed 4000mah that turned out to be 900mah. Here's a list of tested 26650s 26650 Batteries | BudgetLightForum.com. I bought a pair of 5000mah Trustfires that are more like 4000mah, which are actually higher than some other brands, and a pair from one of the guys on BLF that makes his own using Panasonic cells which are usually the best to get.Good Question.
The only ones I've seen recommended are these two:
$12.75 Trustfire TF32650 3.7V 6000mAh Protected Rechargeable Li-ion Battery at FastTech - Worldwide Free Shipping
http://www.kaidomain.com/product/Details.S004141
I couldn't find any better known brands.