APC UPS

Battery use and maintenance

1. Control the reasonable ambient temperature

Ambient temperature is one of the most important factors affecting the life of batteries. Generally speaking, the optimal ambient temperature required by battery manufacturers is between 20-25°C. Although the increase in temperature can enhance the chemical activity of the battery and improve the discharge capacity, it will also greatly shorten the battery life. At present, the batteries used in UPS are generally maintenance-free sealed lead-acid batteries, which can be used for 3-5 years under the environment required by the battery manufacturer. However, if they are used for a long time under an environment that does not meet the requirements, the length of their life will vary greatly. In addition, the increase in ambient temperature will lead to the enhancement of the chemical activity inside the battery, thereby generating a large amount of heat energy, which will in turn increase the ambient temperature. This vicious cycle will accelerate the shortening of the battery life [5]. Therefore, in order to keep the ambient temperature within a reasonable range, the place where the battery is used generally needs to be equipped with an air conditioning system to keep the temperature constant.

2. Regularly charge and discharge

The floating charge voltage and discharge voltage of UPS are related to the number of batteries equipped, and the size of the battery discharge current is proportional to the size of the load. Therefore, the load should be adjusted reasonably during use. Under normal circumstances, the actual load should not exceed 60% of the rated load of UPS. Within this range, the battery will not be over-discharged. If the mains power supply is good for a long time, and the UPS continues to work in the mains inverter mode, for UPS without ABM charging method, the battery will be in a floating charge state for a long time, which will cause a large amount of lead sulfate to be generated inside the battery and adsorbed to the battery cathode, causing the battery internal resistance to increase, activity to decrease, and shorten the service life. Therefore, the battery should be discharged once every 2-3 months, and the discharge time can be determined according to the capacity of the battery and the load size. After the load discharge is completed once, recharge for more than 8 hours as required. In this way, through periodic battery charging and discharging, the battery activity can be kept good and the function is complete, thereby extending the service life.

3.Replace the problem battery in time

According to the load and backup time requirements, UPS needs to be equipped with a large number of batteries. During the long-term operation of UPS, due to differences in the performance and quality of battery cells, it is inevitable that the internal resistance of individual batteries will increase, the performance will decrease, and the storage capacity will decrease [6]. Therefore, the operation and management personnel should regularly monitor and record the various power parameters of the battery and the attribute parameters of the battery cells themselves. By comparing the data, the performance of the battery pack can be judged, and the performance trend of the battery cells can be predicted, so that the problem battery can be discovered early. In order to prevent the problem cell from further deteriorating and affecting other cells, new batteries should be replaced in time to eliminate the hidden dangers of the problem. The newly replaced batteries should be of the same manufacturer and model, and it is forbidden to mix batteries of different specifications and brands. In addition, the replaced problem battery cells can be charged and discharged separately to activate the failed active substances, thereby reducing the internal resistance, compensating for the voltage difference, and replenishing the remaining capacity. The batteries that can be restored can continue to be used as backup batteries, thereby achieving the purpose of cost saving.