INR21700-P42A — 21700 lithium-ion cell
Molicel INR21700-P42A: 4,200 mAh typical (4,000 mAh minimum), 3.6 V nominal, 45 A discharge. The long-running 21700 workhorse: 4,200 mAh with 45 A continuous discharge. Charge window is narrower than newer parts — 0 °C to 45 °C — so packs need thermal management on the charge side.
Specification
INR21700-P42A parameters
| Parameter | Value |
|---|---|
| Brand | Molicel |
| Model | INR21700-P42A |
| Form factor | 21700 |
| Chemistry | NMC |
| Nominal voltage | 3.6 V |
| Typical capacity | 4,200 mAh / 15.5 Wh |
| Minimum capacity | 4,000 mAh |
| Standard charge current | 4.2 A |
| Discharge current | 45 A |
| Internal resistance | AC 10 mΩ (1 kHz) · DC 16 mΩ (10 A/1 s) |
| Energy density | 615 Wh/L · 230 Wh/kg |
| Weight | 70 g (Max) |
| Diameter | 21.55 mm (Max) |
| Height | 70.15 mm (Max) |
| Charge temperature | 0 °C to 45 °C |
| Discharge temperature | -40 °C to 60 °C |
INR21700-P42A — specification and pack integration
The long-running 21700 workhorse: 4,200 mAh with 45 A continuous discharge. Charge window is narrower than newer parts — 0 °C to 45 °C — so packs need thermal management on the charge side.
What the numbers mean for a pack
- 4,200 mAh typical in a 21700 can, at 3.6 V nominal
- 45 A discharge ceiling — the pack design must hold the cell inside its temperature cut-off to use it
- 615 Wh/L · 230 Wh/kg
- AC 10 mΩ (1 kHz) · DC 16 mΩ (10 A/1 s) — the figure that decides voltage sag under load
Where it is used
- E-mobility packs where 45 A continuous per cell is the design point
- Power tool packs moving from 18650 to 21700 for current headroom
- Industrial UPS and backup modules
Integration notes
Charge CC-CV to 4.2 V within the current limits 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.
Documentation
The manufacturer product data sheet for this model is available for download on this page. UN38.3 test summary, MSDS and transport documentation are supplied with shipment.
Specification basis: Molicel Product Data Sheet, model INR-21700-P42A (v1.7)
Compare
Other 21700 cells to quote against
| Model | Brand | Capacity | Discharge | Data sheet |
|---|---|---|---|---|
| INR21700-40T | Samsung SDI | 4,000 mAh | 35 A | Pending |
| INR21700-P45B | Molicel | 4,500 mAh | 45 A | On file |
| INR21700-M50LT | LG Energy Solution | 4,800 mAh | 14.4 A | Pending |
| INR21700-P50B | Molicel | 5,000 mAh | 60 A | On file |
Capacity and discharge figures are the values held for each model; where no manufacturer data sheet is on file the row is marked pending rather than presented as verified.
Applications
Duties this grade of cell is specified for
Cells for drones and eVTOL
45 A continuous, inside the 45–60 A band this duty is written around.
Read the duty profile ApplicationCells for cordless power tools
45 A continuous, above the 20 A floor tool packs are specified at.
Read the duty profile ApplicationCells for e-bikes, scooters and light traction
4,200 mAh at 45 A continuous — the balanced grade traction packs are built from.
Read the duty profileRelated
Where else to look
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