● The charger of lithium iron phosphate battery is different from ordinary lithium battery. The maximum termination charge voltage of a lithium battery is 4.2 volts; The lithium iron phosphate battery is 3.65 volts. The safe operating voltage range of lithium battery is 2.8~4.2V, below or above this voltage range, the lithium ions in the battery become very unstable, and even cause accidents. In order to ensure that the lithium iron phosphate battery is in a safe range, a special charger is required. These chargers automatically adjust the charging mode according to the current state of the battery.
● It is recommended to use CCCV charging mode for lithium iron phosphate battery, that is, constant current before constant voltage. Constant current 0.3C is recommended. The recommended constant voltage is 3.65. that is, 0.3C current charge during the constant current process. When the battery voltage reaches 3.65V, 3.65V voltage constant voltage charge is adopted.
● When charging, the charger is best to choose the original special charger, otherwise it will affect or damage the lithium iron phosphate battery.
Lithium iron phosphate battery charging is divided into two stages
1, constant current charging, that is, the current is certain, and the lithium iron phosphate battery voltage gradually increases with the charging process, in accordance with the above specifications generally to 0.2C current charging (C is a nominal capacity of the battery and current comparison, 0.2C is 200mA), when the battery voltage is close to the full voltage 4.2V, change the constant current charging for constant voltage charging. The process takes about five hours.
Second, constant voltage charging, that is, the voltage is certain, and the current gradually decreases with the saturation degree of the cell, according to the specification, when the current is reduced to 0.01C, that is, 10mA, it is considered that the charging is terminated. After this process and the constant current charging time are added up, the total charging time should not exceed eight hours. Therefore, there are two criteria to determine whether the lithium iron phosphate battery charging has reached saturation: one is that the current is 0.01C, and the other is that the total time does not exceed eight hours, in other words, if the lithium battery charging process can not reach 0.01C after eight hours, it is regarded as unqualified products.
Lithium iron phosphate battery charging requirements
Lithium battery charger requirements are stable voltage and current output, need to have the mainland CCC mandatory certification mark, which is also a requirement for the safety of each product.
Lithium iron phosphate battery capacity below 1000mAh, choose a 5V\/500mA charger or a smaller output current charger.
The charging method of lithium battery is voltage limiting constant current, which is controlled by IC chip, typical charging method is: first detect the voltage of the battery to be charged, if the voltage is lower than 3V, precharge first, charging current is 1\/10 of the set current, after the voltage rises to 3V, enter the standard charging process. The standard charging process is: constant current charging with the set current, when the battery voltage rises to 4.20V, it is changed to constant voltage charging, and the charging voltage is maintained at 4.20V. At this time, the charging current gradually decreases, and when the current drops to 1\/10 of the set charging current, the charging ends.
Regular use of lithium iron phosphate batteries, normal use, long time to charge the battery pack regularly, can ensure the best practical effect of the battery pack, and extend the service life.