Soshine 21700 3C (5000mAh)
A safe bet in 21700 with a real edge: this Soshine 5000mAh cell packs built-in protection, for solid runtime without giving up on safety.
Characteristics
- Format: 21700 (INR21700, 3C)
- Capacity: 5000 mAh
- Continuous discharge: 3C, about 15A
- Protection: Built-in circuit (overcharge/short circuit)
- Protected 21700 cell, rare for this format
Detailed overview: Soshine 21700 3C 5000mAh lithium cell
The Soshine 21700 cell (full name Soshine 21700 3C, reference INR21700) is a rechargeable lithium-ion cell in the 21700 format, larger than the classic 18650 (21.5 mm diameter for about 70.5 mm length, versus 18 x 65 mm). Soshine is a Chinese manufacturer well regarded in the flashlight world, less known to the general public than Samsung or Panasonic but appreciated by enthusiasts for its build quality.
This cell offers a capacity of 5000 mAh (4900 mAh guaranteed minimum), for an energy of 18.5 Wh at a nominal voltage of 3.7V. It supports a continuous discharge of 3C, about 15A, a comfortable level for many uses without targeting the extreme discharge rates of cells built for high-power vaping. Its stated internal resistance stays low, around 15 to 16 mΩ. A notable feature, and fairly rare for this format: the cell has a built-in electronic protection circuit against overcharge, over-discharge and short circuit, which explains its slightly longer length compared to a standard bare 21700.
You find it in powerful flashlights, electric bikes and scooters, DIY battery packs assembled by enthusiasts, and some portable tools, wherever you want good runtime in a compact format. Its built-in protection makes it a reassuring choice for anyone new to the 21700 format, without a real sacrifice in performance. Soshine also offers a 21700 5000mAh variant with a built-in USB-C charging port, pricier and designed to recharge the cell without an external charger: that is not the model described here, which remains the classic protected version, without USB.
Even protected, a lithium-ion cell still needs careful handling: use a charger suited to 3.7V lithium cells, never a NiMH charger, avoid impacts and extreme temperatures, and check compatibility with your device before buying, as some very compact flashlights only accept bare cells with strict dimensions. For everyday use in a flashlight, electric bike or DIY pack, the Soshine 21700 3C is a safe bet, with the extra peace of mind of built-in protection.
Our tester's review: Pierre Freysinger
We tested this Soshine 21700 3C in a hiking flashlight and for a small DIY pack, and the first good surprise is the built-in protection: for anyone not used to handling bare cells, it is reassuring, the circuit cuts off on overcharge or over-discharge. On capacity, the stated 5000 mAh seems to hold up, with runtime close to what a Samsung 50E offers in the same use. First downside: the extra length from the protection (70.5 mm versus 70 mm bare) kept the cell from fitting a very compact flashlight designed for strictly sized bare 21700 cells, so it is worth checking compatibility before buying. Second downside, broader than this specific product: Soshine remains a low-profile brand in the US and Europe, with fewer Western user reviews and less structured after-sales support than Samsung or Panasonic. That said, the build quality feels solid, and the capacity-to-safety ratio is good. An honest protected 21700 cell, best reserved for devices that accept its slightly longer length.
Frequently asked questions: Soshine 21700 3C 5000mAh lithium cell
Both are rated at 5000mAh, but the Soshine has a built-in protection circuit (overcharge, over-discharge, short circuit) while the Samsung 50E is a bare cell. The Soshine is therefore more reassuring to handle, at the cost of a slightly longer length.
Yes, unlike many 21700 cells sold bare, it has a built-in electronic protection circuit against overcharge, over-discharge and short circuit, making it more approachable for less experienced users.
Yes, Soshine offers a 21700 5000mAh variant with a built-in USB-C charging port, pricier and handy for recharging without an external charger. That is not the model described here, which remains the classic protected version without USB.
It suits powerful flashlights, electric bikes and scooters, DIY battery packs and some portable tools, wherever you want good runtime in a compact format.
Use a charger suited to 3.7V lithium-ion cells, never a NiMH charger. Even though it is protected, avoid impacts and extreme temperatures, and check compatibility before buying, as some very compact flashlights require strictly sized bare cells.
Other products in the "21700 batteries" category
Keeppower 21700 5000mAh
$22.06
A high-capacity 21700 cell from a brand known for its built-in protection circuits: the Keeppower 5000mAh targets powerful flashlights and DIY packs.
Klarus 21GT-50 5000mAh
$19.95 (4)
The 21GT-50 is Klarus's high-capacity 21700 battery: 5000mAh, 15A continuous discharge and a built-in protection circuit for the most demanding flashlights and devices.
LG M50T 21700 (5000mAh)
$4.99
5000mAh in a compact 21700 format: the LG M50T targets maximum runtime for DIY packs, e-bikes and long-duration flashlights.
Molicel P42A 21700 (4200mAh)
$5.99 (11)
The 21700 sibling of the 18650 benchmark: 4200mAh and 45A continuous, built for cordless tools, ultra-powerful flashlights and demanding electronics.
Published on 05/09/2026