INR-21700-P50B cylindrical rechargeable battery cell

The INR-21700-P50B is a cylindrical lithium-ion rechargeable cell in 21700 format from Molicel, in the Power Cell series and also listed as the low-impedance version of the P50B. It is a cell-level component for battery pack builders and belongs to the batteries category, with drones, eVTOL aircraft, motorcycle racing and high-performance electric vehicles named by the maker as applications.

The cell combines high capacity with a high discharge rating for its format. Typical capacity is 5.0 Ah at a nominal voltage of 3.6 V, which corresponds to 18 Wh per cell. The maker gives a gravimetric energy density of 260 Wh/kg and a volumetric energy density of 714 Wh/L. Maximum weight is 71 g, so a pack designer can calculate the cell mass of a series-parallel assembly directly. Maximum dimensions are 21.55 mm in diameter and 70.15 mm in height.

Power capability is stated as a 60 A discharge current, described by the maker as 100 W discharge, and a 5 A charge current, described as 5C fast charge power. The low impedance matters for multirotor and eVTOL packs because less of the energy is lost as heat under high-current climb and hover phases, which eases thermal management and keeps voltage sag lower. Actual continuous current in a pack still depends on cell temperature, cooling and the pack's duty cycle.

For integration, the cell is supplied with the 21700 tab design and is built into a pack with series and parallel connections, a battery management system, protection devices and a cooling concept chosen by the pack manufacturer. Voltage, protection and load capability of the final pack are defined at pack level and not by the cell alone.

Molicel lists test reports and certificates for UL, UN and IEC, together with a safety data sheet and a datasheet that can be downloaded after registration. Typical uses are battery packs for multirotor and eVTOL propulsion, high-power electric vehicles, racing applications and other equipment that needs a compact, high-rate cell.