Soshine 26650P 5500mAh

The Soshine 26650P-3.7-5500 is a rechargeable lithium-ion battery in the 26650 format, 26.6 mm in diameter and 2.7 in (68.5 mm) long, the largest of the mainstream cylindrical formats, above the 21700 and the 18650. This larger size targets a specific audience: very powerful flashlights and DIY battery packs that need a large capacity per cell, even at the cost of some compactness. Soshine, a Chinese brand specializing in cells and batteries, has built a solid reputation among flashlight enthusiasts for the reliability of its protected cells.

It is rated at 5500mAh under a 3.7V nominal voltage (20.35Wh), with a maximum charge voltage of 4.2V and a protected discharge cut-off at 2.75V. Continuous discharge current climbs up to 8A, comfortably enough for the most demanding flashlights, and standard charging runs at 2.5A (5A maximum) on a dedicated lithium-ion charger. A PCB circuit is built into the base of the cell, protecting against overcharge, over-discharge and short-circuit. It supports several hundred charge cycles, up to around 1000 according to the manufacturer, a solid lifespan for a mainstream lithium-ion cell.

The real selling point of this Soshine is its length: at 2.7 in (68.5 mm), it is among the few protected 26650 cells that stay under 2.72 in (69 mm). Many powerful flashlights accept bare 26650 cells but reject protected versions, which run a few millimeters longer because of the PCB circuit; this Soshine fits precisely where other protected 26650 cells do not, without giving up the safety of built-in protection.

It naturally suits very powerful flashlights, demanding DIY packs and some portable spotlights that need a large energy reserve per cell. As with any lithium-ion battery, it is best charged with a dedicated charger, kept away from short circuits and used within its stated voltage range: the protection circuit covers the essentials, but does not replace the basic precautions that come with this type of cell.