How does long-term floating charging affect the performance of UPS lithium iron phosphate batteries?
The lithium iron phosphate battery UPS cannot be floated for a long time. Lithium battery charging must require constant current and constant voltage; general lithium batteries are limited to a maximum charging voltage of 4.2V, and it is dangerous to exceed this value; some protection ICs on the market today Both have overcharge protection and overcharge recharge functions, depending on the specific application, choose a good device.
Floating charge is a method of supplying (discharging) the lithium battery pack. The system connects the lithium battery pack and the UPS power line in parallel to the load circuit. Its voltage is generally constant, only slightly higher than that of the lithium battery pack. Terminal voltage, a small amount of current provided by the lithium battery UPS power line to compensate for the loss of local action of the lithium battery pack, so that it can often remain in a charged state without overcharging.
UPS lithium iron phosphate battery floating charging method:
对 Check discharge of lithium battery
The lithium battery UPS is individually discharged to examine whether the lithium battery pack can meet the needs of the maximum average load. This discharge method is called checking discharge. The specific method is: choose to interrupt the work of the high-frequency switching power supply under the condition of maximum load, so that the lithium battery pack is discharged separately, so that the actual power required by the load is entirely borne by the lithium iron phosphate battery pack, and the lithium battery is calculated at the end of discharge The output capacity of the group.
⑵Strengthen the management of floating charge operation mode
The floating charging operation mode is that in the DC power system, a lithium iron phosphate battery pack is connected in parallel with the charging device equipment, and the lithium battery works as the only backup power source that supports the operation of the DC power system of the substation. In the process of floating charge operation, due to the different internal resistance and self-discharge of each lithium battery UPS, their actual capacities are different, and their terminal voltages are inconsistent.
UPS lithium iron phosphate battery charging method:
The charger charges the UPS lithium battery with a constant current. As the battery voltage increases, the charger increases the charging voltage at the same time to speed up the charging speed. When the battery reaches the 4.2V cut-off voltage, at this time the battery only charges about 70% of the charge (not full). At this time, the charger continues to charge the battery with a constant voltage and a gradually decreasing current. When the value is less than 0.1A, the battery voltage is still detected to continue to increase before stopping charging.
When charging the lithium iron phosphate battery UPS and related products, it is best to choose the original dedicated charger. Because the original charger is most suitable for voltage and charging speed, and it will not damage the battery.