If you're like me, new to these new high tech power flashlights and cells, and remember the days of NiCad short shelf life, leakage, and poor cycle life, then you're skeptical about paying too much for cells you don't know will last. Fortunately there are enthusiasts who test and use these cells and lights extensively and share their results. Even then, even when we're convinced and more comfortable with the capability and endurance of ICR, IMR, and primary Lithium cells, we're still skeptical about brands. Certainly what it takes to design, and, more importantly to make these cells requires expertise, equipment, processes, and controls that few manufacturers have mastered around the world. That being the case, it is less likely that major name branded cells will suffer from poor lot to lot variance in capacity, current handling, shelf life, service life, and cycle life. We might tread cautiously with brands whose name we don't recognize, but we can depend that cells branded with the flashlight maker's name will both fit and function in their lights. So that's the first step, and that's what I did in buying a second Nitecore 18650 2600mAH cell to match that included in Nitecore's combo HC30 Kit.
Fit and finish of the cell is fine. Charged with no issues in the Combo Kit's i2 charger. Works, delivering the power of the HC30 light. Amazing power potential for all manner of technology gear. I chose the 2600mAH again from the fear of the bleeding edge... I'd rather have two 2600mAH at a sale price than a 3600mAH at a higher price despite the potential of run time difference. Now if I used a light on high for hours a day, I'd likely have chosen differently. Still, in this point in time it is possible that even Nitecore's and more likely other branded cells of high capacity might actually not fit. Especially when starting out, buying the same one that was originally included is only being wise. And watching buyer feedback about what fit and what didn't in what, or what fit but didn't work in this or that is only wise. I intend to try an Xtar's cell next unless name branded cells go on sale for less.

I bought two of these specific batteries for my flashlight and they are exactly what I wanted. Website was helpful. Price was great. Shipping was fast. (I also liked the free small key chain flashlight included with my order). Very happy.

Love this battery, Fast charging, long lasting. Made my flashlight brighter then the old battery.

I like the Nitecore brand and know they cost more but it is a higher quality and I expect it to last longer than the cheaper no name brands!

Ordered sever of these with the dual charger to always have charged batteries when needed. They seem to last as advertised.