The 21700 lithium battery is a cylindrical lithium-ion battery with a diameter of 21mm and a height of 70mm.
Its size is larger than the traditional 18650 battery, and this design allows for significant improvements in both capacity and discharge performance.
Generally, the typical capacity range for a 21700 lithium battery is between 4000mAh and 5000mAh,
making it particularly effective in applications requiring high energy output.
The nominal voltage of this battery is typically 3.6V or 3.7V, with a charging cut-off voltage of 4.2V and a discharge cut-off voltage of 2.5V.
This voltage range ensures the battery's stability and safety. Furthermore, the maximum discharge current of the 21700 lithium battery is typically between 10A and 30A,
with peak instantaneous discharge capabilities of up to 45A, meeting the demands of high-power devices like power tools and electric vehicles.
Energy density is one of the key indicators of a battery's performance, and the 21700 lithium battery has an energy density of 200-250Wh/kg,
which is about 20% higher than the 18650 battery. This feature means that, for the same weight, the 21700 lithium battery can provide longer endurance,
making it especially crucial for applications that require high efficiency and longevity.
Application Prospects of the 21700 Lithium Battery
Due to its excellent performance, the 21700 lithium battery shows broad application prospects across multiple fields. In the electric vehicle industry,
it has become an important choice for enhancing driving range. The successful implementation of this battery in the Tesla Model 3 has demonstrated its capabilities,
and other automakers are gradually adopting this battery to improve the performance and market competitiveness of their electric vehicles.
In the power tools market, the 21700 lithium battery is highly favored for its high discharge rate and long cycle life.
Whether in drills, angle grinders, or other heavy-duty tools, this battery provides stable and continuous power, meeting the demands of professional users.
Category | Specification |
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3.1 Nominal Capacity | 5000mAh (at 0.2C Discharge) |
Minimum Capacity | 4900mAh (at 0.2C Discharge) |
Measurement Condition | Discharge at 0.2C to 2.5V end voltage after standard full charge at 25°C |
3.2 Maximum Charge Voltage | 4.20V ± 0.03V |
3.3 Average Working Voltage | 3.60V @ 0.2C |
3.4 Standard Charge Method | Method: Constant Current and Constant Voltage (CC/CV) |
| Current: 0.2C (1000mA) |
| Voltage: 4.2V |
| End Current: 100mA ± 5mA |
3.5 Maximum Charge Current | 0℃ ≤ T ≤ 10℃: 0.1C (500mA) |
| 10℃ < T ≤ 20℃: 0.2C (1000mA) |
| 20℃ < T ≤ 45℃: 0.7C (3500mA) |
3.6 Charge Time | Standard Charge: 6.0h |
| Rapid Charge: 2.0h |
3.7 Standard Discharge | Method: Constant Current (CC) |
| Current: 1.0C (5000mA) |
| End Voltage: 2.5V |
3.8 Maximum Discharge Current | -20℃ ≤ T ≤ 20℃: 1.0C (5000mA) |
| 20℃ < T ≤ 35℃: 2.0C (10000mA) |
| 35℃ < T ≤ 45℃: 1.0C (5000mA) |
3.9 Cycle Life | ≥70% of 1st capacity after 500 cycles (25℃ ± 2℃, 4.2V-2.5V) |
Cycle Life Notes | High rates and high temperatures (≥35°C) can shorten cycle life. Safety risks arise at ≥65°C. |
3.10 Weight of Bare Cell | Avg. 72g ± 4g |
3.11 Operating Temperature | Charge: 0°C ~ 45°C |
| Discharge: -20°C ~ 45°C |
