Reliance INR21700-RS50 5000mAh 70A Li-Ion Cell

The Reliance INR21700-RS50 is a high-density lithium-ion bare cell tailored for builders assembling custom long-range FPV battery packs. Combining a substantial 5000mAh capacity with a highly aggressive 70A discharge rating, this 21700 cell bridges the gap between extended flight endurance and high current delivery. This extra discharge headroom prevents the extreme voltage sag commonly seen when flying lower-drain cells on heavier 7-inch to 10-inch cinematic cruisers and fixed-wing UAVs.

Key features

• High-drain INR chemistry minimizes voltage sag during payload-heavy flights or throttle bursts
• Flat-top bare cell design optimized for custom spot-welded 4S or 6S endurance packs
• Significantly higher 70A current ceiling than standard high-capacity 21700 options
• Tabless internal construction

Specifications

• Manufacturer: Reliance
• Model: INR21700-RS50
• Cell Format: 21700 (21 mm diameter, 70 mm length)
• Dimensions: 21.35 x 70.30 mm (max)
• Nominal Capacity: 5000 mAh (4950 mAh minimum)
• Discharge Rating: 70 A
• Nominal Voltage: 3.6 V
• Charge / Cut-off Voltage: 4.2 V / 2.5 V
• Charge Current: 2.5 A standard, 15 A maximum
• Chemistry: INR
• Terminal: Flat top (unprotected)
• Weight: 67 g (approx.)

When assembling custom multi-cell packs, ensure your spot-welding equipment and pure nickel strip thickness are rated to safely carry the potential 70A current delivery.