The 18650 21700 battery is a type of lithium ion battery with a diameter of 18 millimeters and a length of 65 millimeters. It is commonly used in various handheld electronic devices such as laptops, mobile phones, flashlights, drones, etc. Its advantages are lightweight, high energy density, long lifespan, and rechargeability. However, it also has some disadvantages such as being prone to overheating, requiring special chargers, and potential safety issues. Therefore, when using the 18650 battery, safety should be taken into consideration and the correct charging and usage methods should be followed.
Cylindrical rechargeable lithium ion battery
Model name: INR21700-40T 4000MAH
Nominal Specification
| Item |
Condition |
Specification |
| 1 Energy |
Std. charge / discharge |
Nominal 4000mAh
Minimum 4000 mAh |
| 2 Nominal Voltage |
Average |
3.635V |
| 3 Standard Charge |
Constant current
Constant voltage
End current(Cut off) |
0.5C
4.2V
50mA |
| 4 Max. Charge Voltage |
4.2 ± 0.05V |
| 5 Max. Charge Current |
2A |
| 6 Standard Discharge |
Constant current
End voltage(Cut off) |
0.2C
2.5V |
| 7 Max. Discharge Current |
45A |
| 8 Weight |
Approx. |
Max. 70 g |
| 9 Operating Temperature |
Charge
Discharge |
0 ~ 45ºC
-20 ~ 60ºC |
| 10 Storage Temperature |
1 month
3 month
1 year |
-20 ~ 60ºC
-20 ~ 45ºC
-20 ~ 20ºC |
| 11.Initial AC Impedance |
Cell shall be measured at 1kHz after charge per |
≤ 50 mo, without PTC |
| 12.Initial Capacity |
Cells shall be charged pe |
≥ 5000 mAh |
| 13.Cycle Life |
Cells shall be charged and discharged per 4.1.3 400 cycles. |
≥ 80 % |
Rechargeable Lithium Ion Battery
Cylindrical rechargeable lithium ion battery
Model name: INR21700-40T 4000MAH
Diameter: 21.22 +0.1 / -0.3 mm (Max. 21.4mm)
Height: 70.3 ±0.2mm (Max. 70.2mm)
Performance Specification
1. Standard Charge Unless otherwise specified, "Standard Charge" shall consist of charging at constant current of 0.5C. The cell shall then be charged at constant voltage of 4.20V while tapering the charge current. Charging shall be terminated when the charging current has tapered to 50mA. For test purposes, charging shall be performed at 23ºC ± 2ºC.
2. Standard Discharge "Standard Discharge" shall consist of discharging at a constant current of 0.2C to 2.50V. Discharging is to be performed at 23 ºC ± 2 ºC unless otherwise noted (such as capacity versus temperature).
3. High Drain rate Charge/discharge condition Cells shall be charged at constant current of 1,500mA to 4.20V with end current of 100mA. Cells shall be discharged at constant current of 4,000mA to 2.50V. Cells are to rest 10 minutes after charge and 20 minutes after discharge.
Caution Warning
* When using the application equipped with the battery, refer to the user's manual before usage.
* Please read the specific charger manual before charging.
* Charge time should not be longer than specified in the manual.
* When the cell is not charged after long exposure to the charger, discontinue charging.
* Battery must be charged at operating temperature range 0 ~ 45ºC.
* Battery must be discharged at operating temperature range -20 ~ 60ºC.
* Please check the positive(+) and negative(-) direction before packing.
* When a lead plate or wire is connected to the cell for packing, check out insulation not to short-circuit.
* Battery must be stored separately.
* Battery must be stored in a dry area with low temperature for long-term storage.
* Do not place the battery in direct sunlight or heat.
* Do not use the battery in high static energy environment where the protection device can be damaged.
* When rust or smell is detected on first use, please return the product to the seller immediately.
* The battery must be away from children or pets
* When cell life span shortens after long usage, please exchange to new cells.
* Do not use different charger. Do not use jacks (in cars) for charging.
* Do not charge with constant current more than maximum charge current.
* Do not disassemble or reconstruct the battery.
* Do not throw or cause impact.
* Do not pierce a hole in the battery with sharp things. (such as nail, knife, pencil, drill)
* Do not use with other batteries or cells.
* Do not solder on battery directly.
* Do not press the battery with overload in manufacturing process, especially ultrasonic welding.
* Do not use old and new cells together for packing.
* Do not expose the battery to high heat. (such as fire)
* Do not put the battery into a microwave or high pressure container.
* Do not use the battery reversed.
* Do not connect positive(+) and negative(-) with conductive materials (such as metal, wire)
* Do not allow the battery to be immerged in or wetted with water or sea-water
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