EVE Energy Co., Ltd. INR21700/40PL
Series: EVE Energy Co., Ltd. Battery cells for drone packs
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The EVE INR21700/40PL is a high-power round cell in the 21700 format from EVE Energy, a Chinese maker of lithium batteries. The cell uses a tabless design, meaning without individual current-collector tabs, and is intended for small FPV drones with high current demand. The format 21700 states diameter and length: 21 mm and 70 mm.
It stores 4,000 mAh at 3.6 V nominal voltage, which is 14.4 Wh per cell (nominal voltage times capacity). The weight is around 68 g, the dimensions 21.4 × 70.0 mm. Tabless means the current is carried away not through individual tabs but across the whole edge of the winding, which lowers internal resistance and heating at high currents. For continuous current, figures of 25 A, 70 A and 100 A circulate depending on the source; they apply under different conditions and are not equivalent. Only the EVE data sheet is binding.
A pack of six cells (6S1P) comes to 86.4 Wh and so stays below the 100 Wh limit above which IATA requires airline approval for spare batteries in passenger flights; above 160 Wh carriage is ruled out. Lithium cells must also meet the tests of UN 38.3 and be packed protected against short circuit. Joining cells into a pack belongs in specialist workshops with test and protection equipment.
Because the current limit varies so widely with the source, plan with a large reserve when choosing and measure the actual pack current. Heavily loaded round cells are often counterfeited or re-wrapped; buying from reputable dealers protects against cells with false capacity. In cold weather keep the pack warm before flight and do not charge below 0 °C.
Technical data
Other data
| Capacity (mAh) | 4,000correct |
|---|---|
| Cell chemistry | Li-Ioncorrect |
| Cell count (S) | 1Scorrect |
| Form factor | 21,700correct |
| Nominal voltage (V) | 3.6 Vcorrect |
| Weight (g) | 68correct |
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