INR21700-50S — 21700 lithium-ion cell

About the Samsung SDI INR21700-50S 21700 Li-ion Cell 5,000 mAh 25 A

The INR21700-50S is the cell that put 5 Ah and genuine high power in the same 21700 can. It holds 25 A continuous discharge with no temperature cut-off applied, and the 45 A figure only applies when the pack enforces an 80 °C surface cut. Charge side is equally useful: 6 A rated continuous, 10 A step charging.

Why pack builders specify it

• 25 A continuous without temperature cut-off — the highest continuous figure in this Samsung 21700 group
• 45 A is conditional on an 80 °C cell-surface cut being enforced by the pack, not a free rating
• 6 A rated charge (100 min) with 10 A step charging shortens turnaround on tool and light-EV packs
• 5,000 mAh typical against 4,000 mAh on the 40T, so high-drain packs gain runtime without a second parallel string

Typical applications

• Cordless power tools – 3S and 4S professional tool packs; 6 A rated charge supports fast turnaround on site
• E-motorcycles and high-performance scooters – 25 A continuous per cell keeps parallel counts down in high-draw traction packs
• Industrial robots and AGVs – Handles peak torque events without the voltage sag of an energy cell
• High-drain portable equipment – Where a 21700 slot has to deliver both runtime and burst current

Where it fits

Choose the 50S when the pack pulls hard and long — power tools, light EV traction, robot axes. The 40T still wins on sustained 35 A with lower sag and costs less per cell. If the load stays under 10 A, the 50E or 50GB gives more capacity for the money.

Charging and pack integration

Charge CC-CV to 4.2 V within the current limits listed above and stop discharge at 2.5 V. These are unprotected industrial cells: a BMS or protection circuit is required, interconnects must be resistance or laser welded rather than soldered, and cells of different model, batch or state of charge must not be mixed in one pack. Charging below 0 °C is not permitted unless the pack implements a low-temperature charge strategy.

Certifications and documentation

UN38.3, MSDS, IEC 62133-2, UL 1642, CE, RoHS, REACH, PSE, KC, BIS, CB. UN38.3 test summary, MSDS and the cell specification are available on request.

Specification basis: Official Samsung SDI spec.