21700 3.7V 4000mAh 10C Lithium Ion Battery Cell INR21700 High Discharge Rate 40A

Description

• 1. General Specifications

  • Battery Model: 21700 Lithium Ion
  • Nominal Voltage: 3.7V
  • Nominal Capacity: 4000mAh (4Ah) (at 0.2C Discharge)
  • Internal Resistance: ≤15mΩ (Measured at 1kHz AC)

  2. Charging Specifications

  • Standard Charging Current: 0.5C (2A)
  • Fast Charging Current: 2C (8A)
  • Charging Voltage: 4.2V
  • Charge Method: CC-CV (Constant Current-Constant Voltage)
  • Charging Time: ~2.5-3 Hours (Standard Charge)

  3. Discharge Specifications

  • Standard Discharge Current: 1C (4A)
  • Maximum Continuous Discharge Current: 10C (40A)
  • Pulse Discharge Current: 20C (80A)
  • Discharge Cut-off Voltage: 2.5V

  4. Environmental Conditions

  • Operating Temperature (Charge): 0°C to 45°C
  • Operating Temperature (Discharge): -20°C to 60°C
  • Storage Temperature: -20°C to 45°C (Short Term) / 25°C (Recommended for Long-term Storage)
  • Humidity: ≤85% RH

  5. Physical Characteristics

  • Cell Dimensions:

    • Diameter: 21.2mm
    • Height: 70.5mm
  • Weight: Approx. 66g
  • Terminal Type: Flat top or Button top

  1. Capacity Comparison: 4000mAh vs 5000mAh

  • • 21700 4000mAh 10C:

      • This battery has a capacity of 4000mAh, meaning it can store 4000mAh of energy, which translates into a moderate runtime for devices requiring significant power.
      • Suitable for medium-power applications where both high discharge rates and reasonable capacity are required.
    • 21700 5000mAh 3C:
      • With a capacity of 5000mAh, this battery can store more energy, providing longer runtime for devices that need extended usage without recharging.
      • This is a better choice for low-to-medium discharge rate applications that need longer run time but don’t require the extreme power output of a high C-rate battery.

  Verdict: The 5000mAh battery offers a longer runtime due to its higher capacity, but the trade-off is the lower discharge rate.

  2. Discharge Rate Comparison: 10C vs 3C

  • 21700 4000mAh 10C:

    • The 10C discharge rate means this battery can handle up to 40A continuously (10 times the capacity), which is very high. This is ideal for high-drain devices such as powerful flashlights, electric vehicles, power tools, and devices requiring short bursts of high energy.
    • Provides high performance in power-hungry applications where intense, short bursts of power are necessary.

  • 21700 5000mAh 3C:

    • The 3C discharge rate means this battery can only handle up to 15A continuously (3 times the capacity). While still suitable for many consumer electronics, it is not as suited for high-drain applications that require sustained, high output.
    • This makes it a better option for low-to-medium power applications where longer runtime is a priority over maximum performance. Verdict: The 4000mAh 10C battery is designed for high-drain devices that need short bursts of high power, while the 5000mAh 3C is better suited for devices requiring longer runtimes but less intense power output.

  3. Application Suitability

  • 21700 4000mAh 10C:

    • Ideal for devices that require intense power output in short bursts such as flashlights, vaping devices, high-power electric bikes, and power tools.
    • Performance-driven applications where high performance and fast discharge rates are critical.

  • 21700 5000mAh 3C:

    • Best for devices that prioritize long battery life over high output, such as medium-power flashlights, solar lights, electric vehicles, and portable power stations.
    • Suitable for applications that don’t demand extreme discharge rates but benefit from extended operation time.

  4. Battery Life and Efficiency

  • 21700 4000mAh 10C:

  • Due to the higher discharge rate, the 4000mAh 10C battery will likely experience more rapid depletion when used at full power. However, it offers greater peak power when required.

  • Excellent for applications needing instant power but may require more frequent recharging if used continuously at high power.

  • 21700 5000mAh 3C:

    • The 5000mAh 3C battery offers longer battery life, as it is designed for lower discharge rates and can provide consistent power over a longer period without depleting quickly.
    • Ideal for applications where efficiency and longer operating hours are prioritized over high instantaneous power.