Nitecore NL2160 21700 (6000mAh)

The Nitecore NL2160 represents the brand's new generation of 21700 cells, with an impressive 6000 mAh capacity (21.6 Wh at 3.6V), among the highest currently available in this format. The 21700, larger than the 18650 whose uses it shares, has become the reference format in recent years for the most powerful flashlights and headlamps, as well as for custom packs seeking maximum runtime per cell.

At 0.87 in (22 mm) in diameter and 2.97 in (75.4 mm) long (2.68 oz / 76 g), the NL2160 supports a continuous discharge of up to 8A, enough for the vast majority of high-power flashlights on the market. It also stands out for its IPX6 certification: welcome water resistance for outdoor use, in the rain or on a damp hike, where many bare cells offer no such protection at all.

The protected Button Top format packs a complete electronic circuit (PCB) that continuously monitors charging, discharging and short circuits, backed up by a pressure relief valve and nickel-plated stainless steel connectors resistant to corrosion. This cell has no built-in USB charging port: it recharges with an external Li-ion 21700-compatible charger, like most Nitecore multi-format chargers.

Worth checking before buying: not every 21700 cell is interchangeable between flashlights, and the slightly larger diameter of some high-capacity versions may not fit every cell holder. Check your device's compatibility. For users after the maximum runtime per cell without changing format, the NL2160 is currently one of the best protected 21700 options on the market.