The battery is an important part of the UPS system,Its pros and cons are directly related to the reliability of the entire UPS system.At the same time, its price is relatively high, generally accounting for the cost of UPS system1/4 to 1/3 of that. Practice has proved that battery failure accounts for UPS.More than 40% of the overall system failure, it is one of the devices with the shortest mean time between failures. Therefore, the choice of UPS battery is not only related to economic cost but also directly affects the uninterrupted power supply of UPS power supply. 1.The feature of UPS battery. Different power devices need to be configured to match their characteristics. When choosing a UPS battery, firstly you should make clear about features of UPS batteries. Conditions that UPS batteries should meet: (1) Valve-regulated drill-acid battery;. (2) The battery backup time is generally within 2h.High current discharge performance; (3) Supply power to the load through the inverter; (4) Generally 12 V/ell (2 V/(el) is rarely used; (5) The service life is generally 3-8 years. 2 Confirmation of battery capacity The Confirmation of battery capacity is important for UPS system design content. Too high and too low battery capacity for UPS system Operation is unfavorable. If the capacity is too high, the investment cost will increase.And it is easy to cause deep discharge of the battery with a small current, causing permanent damage to the battery. if the capacity is too low, it cannot meet the uninterrupted power supply of the load requirements, and high-current charging and discharging will shorten the battery life.Therefore, the correct choice is compatible with UPS capacity and load capacity is to control the investment cost of the UPS system to ensure the key to uninterrupted power supply reliability. 3 How to configure the battery The voltage of single battery is 2V, 4V, 6V, 12V, etc. Under the same capacity configuration, the single battery voltage is Higher, the cheaper the whole battery pack. Considering the cost, installation, Maintenance and other factors, UPS battery-generally choose the single battery voltage as12 V. Because a 380V system requires 32 units 12 V batteries And 2V batteries need 190 units which brings about installation and maintenance a lot of inconvenience. The higher the single battery voltage, the greater for the unbalanced possibility, the faster the deterioration. therefore, the 12 V single battery Security is poor. If one 12 V battery is broken, the whole set is decreased 12V. So many designs will use 2 groups or connect the batteries in parallel, if any group of batteries is damaged, other groups of batteries can be used, improved the safety of power supply. But too many battery packs in parallel will result in capacity loss and a decrease in cell voltage balance, resulting in the capacity is reduced and the life is shortened, so it is best not to connect battery packs in parallel more than 4 groups. 4 considerations of Battery life Battery life refers to the number of battery charge-discharge cycles at a certain depth of discharge in a constant temperature environment, not the true lifespan. The battery’s ambient temperature, discharge frequency, depth of discharge, charging voltage, ripple current and other factors will affect battery life. Generally speaking, UPS battery life is divided into four grades: 3-5 years, 5-8 years, 10 years, and 10 years. According to experience, the actual battery life is usually 50% to 70% of the nominal life. Choosing a long-life battery also means more expensive prices and more comprehensive maintenance. Therefore, when choosing the battery life, one should not simply seek for a long life, but should comprehensively consider the expansion and development of the communication system, the UPS update age, the battery price, and the maintenance status. At present, the battery life of small UIs (under 10 kVA) is generally 3 to 5 years, and the battery life of large and medium UPS (above I0kVA) is generally 5 to 8 years. 5.Selection for UPS brand. European brand batteries generally use 20 ℃ as the standard operating temperature, while China, the United States and Korea all use 25 ℃ as the standard. Generally speaking, at a discharge rate of 10 h, for every 1 degree increase in temperature, the capacity increases by 0.6%. Therefore, install the battery at a temperature of 20 ℃ in an environment of 25 ℃, and discharge capacity will increase slightly due to temperature rising. The principle of electrochemistry shows that the life span will be shortened by 50% every time the temperature rises by 10℃. If keeping the original life of the battery, The ambient temperature must be controlled at 20 ℃. so in areas with higher temperatures in the south, the daily air-conditioning electricity bill will be relatively higher, increasing operating costs. In addition, each manufacturer, each series, and each batch of batteries have quality differences. The real quality of valve-regulated lead-acid batteries. It is difficult to identify. Therefore, when choosing a battery, it is necessary to think about long-term used experience, preferably products with strong professionalism and high cost performance, and products with good after-sales service. If you don’t know what brand to choose, I recommend VELA to you, we can provide you with high-quality and good services, welcome to give advice on us. Summary With the rapid development of computers and networks, UPS power supplies have been widely used in communication systems. Therefore, how to choose UPS batteries has become an important topic for telecommunication power workers. According to the characteristics of the UPS battery, in order to select a suitable battery. a comprehensive analysis is carried out from various aspects such as battery type, capacity calculation, configuration mode, life and brand.