How to Maintain UPS Battery Life?

When using uninterruptible power supply (UPS) system, people tend to unilaterally believe that there is no need to maintain batteries. However, the data show that the proportion of UPS host failure or abnormal operation caused by battery failure is about 1/3. Therefore, it is more and more important to strengthen the proper use and maintenance of UPS battery for prolonging the service life of batteries and reducing the failure rate of UPS system.

♦ Maintaining the appropriate UPS battery environmental temperature

Environmental temperature is an important factor affecting the service life of batteries. In general, the optimum environmental temperature required by battery manufacturers is between 20℃ and 25℃. Although the rise of temperature can improve the discharge capacity of batteries, the cost is the greatly shortening of service life of batteries. According to the test results, once the environmental temperature is over 25℃, the service life of batteries will be reduced by half for every 10℃ of increase. At present, batteries used by uninterruptible power supply are generally sealed lead-acid batteries that do not need to maintain, and their service life are designed for 5 years, which can be achieved only in the environment required by battery manufacturers. If the required environmental conditions, there will be great difference in their service life. In addition, the rise of environmental temperature will strengthen the chemical activity inside the batteries, which will generate a lot of heat energy and promote the rise of environmental temperature conversely. This vicious cycle will accelerate the shortening of UPS battery life.

♦ Regular charging and discharging of UPS battery

The floating voltage and discharge voltage in UPS batteries have been adjusted to the rated value when leaving the factory, while the discharge current increases with the increase of the load, so the load should be adjusted reasonably in use, such as controlling the number of microcomputers and other electronic devices. Generally, the load should not exceed 60% of the rated load of uninterruptible power supply. Within this range, there will be no excessive discharge in the discharge current of UPS batteries.

Since the uninterruptible power supply is connected with commercial power for a long time, the batteries will be in floating charge for a long time in the environment with high quality power supply and few blackouts of commercial power, which will lead to the decrease in the activity of the conversion between chemical energy and electric energy, accelerate aging and shorten the service life of UPS batteries. Therefore,the UPS batteries should be fully discharged every 2-3 months, and the discharging time depends on the capacity and load of batteries. After a full-load discharge, the UPS batteries should be recharged for more than 8 hours according to the regulations.

♦ Reasonable utilizing UPS communication function to monitor the battery

At present, most large and medium-sized uninterruptible power supplies have the operational performances of communication with microcomputers and program control. The microcomputer can communicate with UPS by installing corresponding software on the microcomputer, connecting UPS through serial/parallel ports and running the program, mainly functions include information inquiry, parameter setting, timing setting, automatic shutdown and alarm. Through information inquiry, information such as input voltage of commercial power, output voltage of UPS, load utilization ratio, utilization ratio of battery capacity, internal temperature and frequency of commercial power can be obtained. Through parameter setting, basic characteristics of UPS, battery duration and alarm of battery exhaustion can be set. By means of these intelligent operations, the use and management of UPS power supply and its batteries can be greatly facilitated.

♦ Replacing the waste or bad battery in time

At present, the number of batteries equipped by large and medium-sized UPS power supply ranges from 3 to 80, or even more. These individual battery is connected by circuits to form a battery pack, so to meet the requirements of DC power supply of UPS. In the continuous operation and use of UPS, it is inevitable that the performance of individual batteries will decline, and the storage capacity will fail to meet the requirements and damage due to the difference in performance and quality. When one or some batteries in the battery pack are damaged, the maintenance staff should check and test each battery to eliminate damaged battery. When replacing new batteries, we should try to purchase the batteries of the same type and same manufacturer. Do not mix acid-proof batteries with sealed batteries, or the batteries of different specifications.