3.7 volt 18650 lithium battery

What voltage should be used to charge a 3.7v lithium battery

2018-06-01 82191 views

Generally, a 3.7v lithium battery needs a "protection board" for overcharge and overdischarge. If the battery does not have a protection board, it can only use a charging voltage of about 4.2v, because the ideal full charge voltage of a lithium battery is 4.2v, and the voltage exceeds 4.2v. Damage to the battery, while charging in this way, it is necessary to monitor the condition of the battery at all times.

5v can be used if there is a protective board (4.8 to 5.2 can be used), the USB5v of the computer or the 5v charger of the mobile phone can be used.

For a 3.7V battery, the charge cut-off voltage is 4.2V, and the discharge cut-off voltage is 3.0V. Therefore, when the open circuit voltage of the battery is lower than 3.6V, it should be able to charge. It is best to use the 4.2V constant voltage charging mode, so you don't need to pay attention to the charging time. Charging with 5V is prone to danger of overcharging.

1. Float charge. Refers to charging while working online. This method is often used in backup power supply occasions. If it is lower than 12 volts, it cannot be charged, and if it is too high, it will affect the operation of the circuit. Therefore, when the floating charge works, the voltage is 13.8 volts.

2. Cycle charging. Refers to fully charging the battery to restore the capacity. When fully charged, the charger is not disconnected for measurement. Generally, it is around 14.5 volts, and the maximum does not exceed 14.9 volts. After disconnecting the charger for 24 hours, it is generally around 13 volts to 13.5 volts. About 12.8 to 12.9 volts after a week. The specific voltage value of different batteries is different.

The usual lithium battery cell is 3.7v, the voltage is 4.2v when fully charged, the nominal voltage after series connection is only 7.4v, 11.1v, 14.8v... the corresponding full voltage (that is, the no-load output voltage of the charger) is 8.4v, 12.6v, 16.8v... cannot be 12v integers, just like the interval of lead-acid storage battery is 2v, full is 2.4v, correspondingly only the nominal 6v, 12v, 24v... full voltage (The same is the output voltage of the charger) respectively 7.2v, 14.4v, 28.8v... I don't know what kind of lithium battery you are?

The output of the charger is generally 5V, and 4.9 volts is also a non-standard. If you want to use this charger to charge the battery directly, it will definitely not work, but as long as it is charged by a mobile phone or a dock, it has a control circuit inside. It will be limited within the allowable range of the lithium battery, unless the circuit is damaged, don't worry about this

The usual lithium battery cell is 3.7v, the voltage is 4.2v when fully charged, the nominal voltage after series connection is only 7.4v, 11.1v, 14.8v... the corresponding full voltage (that is, the no-load output voltage of the charger) is 8.4v, 12.6v, 16.8v... cannot be 12v integers, just like the interval of lead-acid storage battery is 2v, full is 2.4v, correspondingly only the nominal 6v, 12v, 24v... full voltage (The same is the output voltage of the charger) respectively 7.2v, 14.4v, 28.8v... I don't know what kind of lithium battery you are?

18500 batteries are widely used in cylindrical lithium batteries, and can be used in electronic fields such as electronic cigarettes, toys, security, and vehicles.

Enterprises with mature cell technology include BAK, Tiansheng, Huayuebao and other manufacturers, with stable performance. The definition rule of its model is: For example, 18650 type refers to a battery with a diameter of 18mm and a length of 65mm, and a 18500 battery with a diameter of 18mm and a length of 50mm, which is a cylindrical battery.

Voltage: 3.6V (conventional universal battery, used for electronic products and low-power electrical equipment with a maximum discharge of 1C. Discharge conditions can be changed according to the situation)

3.2V (power battery can be customized according to the situation)

Charging parameters: 4.2V

The minimum discharge end voltage is generally: 2.75V, the maximum charge end voltage: 4.20V (Sanyo, Samsung, Panasonic, Tiansheng TS/the latest large-capacity 18500 charge end voltage is 4.35V)

Capacity: 3.6V lithium cobalt oxide current technology reaches 1900AMH (according to Tiansheng Weiye Technology Department)

Diameter: 18±0.2

Battery Specification Chart

Battery Specification Chart

The minimum discharge termination voltage is generally: 2.75V

18650 type lithium battery

Maximum charge termination voltage: 4.20V (Sanyo, Samsung, Panasonic's latest large-capacity 18650 charge termination voltage is 4.35V)

Height: 50±0.3

Edit common combination parameters

Combination method: ICR18500-4S2P

Nominal voltage: 14.8V

Output voltage range: 10~16.8v

Nominal capacity: 3000mAh

Standard continuous discharge current: 0.2C

The maximum continuous discharge current: 1C

Working temperature: Charging: 0~45℃

Discharge: -20~60℃

Product size: MAX35*54*83mm

Finished product internal resistance: ≤250mΩ

Lead type: national standard line UL1007/18#, line length 150mm

Protection parameters:

Overcharge protection voltage/4.25±0.025V per string

Over-discharge protection voltage 2.5±0.08V

Overcurrent value: 4~8A

The choice of charger[edit]

Standard charging: The battery is first charged with a constant current of 0.5C5A (1.5A) to 4.2V, and then charged with a constant voltage of 4.2V until the current decreases to 0.01C5A when the charging current gradually decreases. The charging time is about 3 hours. There should be no permanent damage to the rechargeable battery within 0~45°C.

Standard discharge: After a fully charged 18500 battery is placed at an ambient temperature of 20±5°C for 30 minutes, it is discharged to 6.0V at a constant current of 0.2C5A, and the discharge time is about 5 hours. Therefore, it is suitable to choose a 4.2V/1A lithium battery charger.