1. Regular inspection

　　 Regularly check the terminal voltage and internal resistance of each unit battery. For 12V battery cells, if the terminal voltage difference between each battery cell exceeds 0.4V or the internal resistance of the battery exceeds 80mΩ during the inspection, the battery cells should be balancedly charged to restore the internal resistance of the battery. And eliminate the terminal voltage imbalance between each unit cell. When equalizing charging, the charging voltage can be 13.5~13.8V. The vast majority of batteries that have been well-balanced and charged can restore their internal resistance to below 30mΩ.

During the operation of the UPS power supply, the above-mentioned imbalance caused by the changes in the characteristics of each unit battery over time cannot be eliminated by the charging circuit inside the UPS power supply. Therefore, the battery with this characteristic has obvious imbalance. If the group does not take the offline equalization process in time, its imbalance will become more and more serious.

　　2, re-float

　　 The UPS power supply has been shut down for more than 10 days. Before restarting, the UPS power supply should be started without load to use the internal charging circuit to re-float the battery for more than 10-12 hours and then run with load.

　　 The UPS power supply has been in a floating charge state for a long time without a discharge process, which is equivalent to being in a "storage standby" state. If this state lasts for too long, the battery will fail due to "storage for too long", which is mainly manifested as the increase of the internal resistance of the battery, which can reach several Ω in severe cases.

　　 We found that after storage for 1 month at room temperature of 25°C, the usable capacity of the battery is about 97% of its rated value. If it is stored for 6 months, its usable capacity becomes 80% of its rated capacity. If the storage temperature increases, its usable capacity will decrease.

　　 Therefore, it is recommended that the user should deliberately unplug the mains input every 2 months, and let the UPS power supply work in a state where the battery provides energy to the inverter. But this kind of operation should not take too long. When the load is about 30% of the rated output, discharge for about 10 minutes.

　　3, reduce deep discharge

　　 The service life of a battery is closely related to the depth to which it is discharged. The lighter the load carried by the UPS power supply, the greater the ratio of the available capacity of the battery to its rated capacity when the mains power supply is interrupted. In this case, the battery is discharged when the UPS power supply automatically shuts down due to low battery voltage. The depth is deeper.

　　 How can the actual process reduce the occurrence of deep discharge of the battery? The method is simple: when the UPS power supply is interrupted by the mains power supply, and the battery supplies power to the inverter, most UPS power supplies will ring a periodic alarm with an interval of about 4s to inform the user that the battery is now providing energy . When the alarm sound becomes rapid, it means that the power supply has been deeply discharged, and emergency treatment should be carried out immediately, and the UPS power supply should be turned off. It is not unavoidable. Generally, do not let the UPS power supply work until it automatically shuts down due to low battery voltage.

　　 4. Use peak power supply to charge

For users who have long-term UPS power supply at low voltage or frequent power outages, in order to prevent the battery from being damaged prematurely due to long-term insufficient charging, it is necessary to make full use of the power supply peak (such as late at night) to charge the battery to ensure that the battery is discharged every time There is enough charging time afterwards. Generally, after a battery is deeply discharged, it takes at least 10 to 12 hours to recharge to 90% of the rated capacity.

　　 5. Pay attention to the choice of charger

　　Maintenance-free sealed lead-acid batteries for UPS power supply cannot be charged with SCR-type "quick chargers". This is because this kind of charger will cause the battery to be in both "instantaneous overcurrent charging" and "instantaneous overvoltage charging" at the same time. This kind of state will greatly reduce the available capacity of the battery, and will cause the battery to be scrapped in severe cases. When using a UPS power supply with a constant voltage cut-off charging circuit, be careful not to set the battery voltage too low protection operating point too low, otherwise, it will easily cause over-current charging in the early stage of charging.

　　Of course, it is best to use a charger with both constant current and constant voltage to charge it.

　　6. Ensure the ambient temperature of the power supply

　　The available capacity of the battery is closely related to the ambient temperature. Under normal circumstances, the performance parameters of the battery are calibrated at room temperature of 25℃. When the temperature is lower than 25℃, the available capacity of the battery will decrease, and when the temperature is higher than 25℃, the available capacity of the battery will be reduced. The capacity will increase slightly.