Sunpower INR21700-4000 Li-ion Cell, 4000mAh, 30A

The Sunpower INR21700-4000 is a high-discharge Li-ion cell with 4000 mAh capacity and a 30 A continuous discharge rating, designed for applications where power delivery and reliability are essential.

It is well-suited for FPV drones, UAVs, e-mobility devices, and high-drain battery packs, striking a balance between endurance and current output. Compared to capacity-oriented 5000 mAh cells, it offers superior current handling while still delivering reasonable runtime.

With its low internal resistance (~14–16 mΩ), the Sunpower 4000 maintains stable voltage under load, ensuring consistent motor and electronics performance in UAV and industrial applications.

Key Specifications:

• Type: Li-ion Rechargeable Cell

• Model: Sunpower INR21700-4000

• Format: 21700 cylindrical

• Nominal Capacity: 4000 mAh (4.0 Ah)

• Nominal Voltage: 3.6 V

• Full Charge Voltage: 4.2 V

• Cut-off Voltage: 2.5 V

• Max Continuous Discharge: 30 A

• Peak Discharge: up to 35–40 A (≤5 s)

• Internal Resistance (IR): ~14–16 mΩ

• Energy: ~14.4 Wh

• Chemistry: NMC (LiNiMnCoO2)

• Dimensions: Ø 21 mm × 70 mm

• Weight: ~68–70 g

• Cycle Life: 300–500+ (with proper care)