INR21700-40T — литий-ионный элемент 21700

About the Samsung SDI INR21700-40T 21700 Li-ion Cell 4,000 mAh 35 A

The INR21700-40T is the sustained-current option in Samsung's 21700 line. It trades 1,000 mAh against the 50S for 35 A continuous discharge and an initial AC impedance at or below 12 mΩ, which keeps voltage sag predictable when the load is heavy and continuous. Rated 6 A charge brings a pack back in roughly 70 minutes.

Why pack builders specify it

• 35 A continuous discharge, the highest unconditional figure in this group
• Initial AC impedance at or below 12 mΩ keeps terminal voltage up under sustained load
• 6 A rated charge fills a cell in about 70 minutes versus 180 minutes on the 2 A standard rate
• Long production history means holder, busbar and BMS options are mature and well documented

Typical applications

• FPV racing and freestyle drones – Sustained high current with flat voltage under full throttle; 4,000 mAh keeps all-up weight sane
• Cordless power tools – Drills, saws and grinders that pull hard in repeated bursts
• E-scooters and e-skateboards – 35 A continuous suits compact packs with few parallel cells
• High-output lighting – Searchlights and work lights that run at the top of their output range

Where it fits

Use the 40T where the load is genuinely continuous and high — FPV, tools, small high-power traction packs. If runtime is the priority and current stays under 15 A, the 53G or 50E stores more energy per cell and per gram of pack mass.

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.

Packaging

Specification basis: Official Samsung SDI spec.