XCell 21700 Li-Ion Rechargeable Battery 3.7 V 4000 mAh Protected Flat Top (151621)

The XCell 21700 lithium-ion rechargeable battery delivers 4000 mAh at 3.7 V with a built-in protection circuit, making it a reliable power source for high-drain devices such as flashlights, power tools, and e-bikes. Its flat top design and 10 A maximum continuous discharge current ensure compatibility with a wide range of applications.

Advantages

Integrated PCB protection prevents overcharge, over-discharge, short-circuit, and overcurrent, extending battery life and enhancing safety. With up to 500 charge cycles, it offers long-term value. The 21700 format provides higher capacity than 18650 cells while maintaining a compact size.

Suitable for

• High-performance flashlights and headlamps
• Cordless power tools and garden equipment
• E-bikes and electric scooters
• DIY electronics projects requiring reliable power

Key specifications

• Battery type: Lithium-Ion (Li-Ion)
• Size: 21700
• Nominal voltage: 3.7 V
• Capacity: 4000 mAh
• Energy rating: 14.8 Wh
• Rechargeable: Yes
• Protection circuit: Yes (integrated PCB)
• Terminal type: Flat top
• Max continuous discharge current: 10 A
• Charging voltage: 4.2 V
• Standard charge current: 2000 mA
• Cycle life: Up to 500 cycles
• Operating temperature (discharge): -20°C to 60°C
• Operating temperature (charge): 0°C to 45°C
• Safety features: Overcharge, over-discharge, short-circuit, overcurrent protection
• Quantity per pack: 1

Recommendations

Use a quality charger designed for 21700 Li-Ion cells and always observe polarity. Store in a cool, dry place when not in use.