UPS battery use and maintenance

The use and maintenance of UPS batteries is similar to that of computers. The development history of UPS is not long. As an emerging industry, it is the crystallization of high technology, combining today's advanced microelectronics and software technology. High-power UPS is expensive, and the price of batteries accounts for a large proportion, generally accounting for about 30%-50% of the total price of UPS. Among the UPS returned for repair, the proportion of UPS not working properly due to battery failure is about 1/3. It can be seen that the correct use and maintenance of batteries is not a trivial matter to extend the service life of batteries and should not be taken lightly.

The host of UPS is in a core position, and it is also the one that is taken special care of at ordinary times, while another important component-battery is often ignored, thinking that it is maintenance-free and no longer concerned. You should know that a UPS without a battery is of little use, cannot provide power protection, and is at best just a voltage stabilizer, and it also consumes a lot of electricity in vain. Sometimes users mistakenly believe that the battery is also in a usable state when the host is running normally, but they don't know that the battery pack may have no power storage capacity and cannot supply power. After a sudden power outage, the UPS will be powered off immediately or can only be shut down for a short time, so that the user has no time to take remedial measures, and the loss is irreversible. The batteries used in UPS are generally maintenance-free lead-acid batteries, with a design life of 5 years. The longest life is 10 years and 15 years, but the price is much more expensive. The design life of 5 years can only be achieved under the environment required by the battery manufacturer. If the user cannot meet the requirements, it is difficult to say. The typical factor affecting the battery life is the ambient temperature. Generally, the ambient temperature required by the battery manufacturer is between 15 and 25℃. With the increase of temperature, the discharge capacity of the battery is improved, but it is not higher than 30%. The price paid is a greatly shortened battery life, because once the ambient temperature exceeds 25℃, as long as the temperature increases by 10℃, the battery life is shortened by half. For example, if the battery life is 5 years, if the ambient temperature is 35℃, then the battery life is only 2.5 years. If the temperature rises by 10℃ to 45℃, the battery life is only 1.25 years, or even less. When users mistakenly believe that the battery life is still 3 or 4 years, they don't know that the battery has already broken down, generating a lot of heat energy, which can easily increase the surrounding temperature and easily exceed the upper limit of 25℃. If conditions permit, the UPS should be placed in an air-conditioned environment. In order to increase the service life of the battery, it is also necessary to strictly follow that the charging current must not exceed the maximum charging current allowed by the battery. Excessive charging current will shorten the battery life.

After the new battery is installed, it is generally necessary to charge it for a long time. For the initial charge, it should be charged at a current of 1/10 of the rated capacity. The battery can be recharged at the end of discharge, which is called normal charging. During normal charging, it is best to use a graded constant current charging method, that is, use a larger current at the beginning of charging, and use a smaller current after a certain period of charging, and use an even smaller current at the end of charging. This charging method has a higher charging efficiency, a shorter charging time, a good charging effect, and is beneficial to extending the battery life. When the battery is over-discharged to zero output voltage, or the battery is placed in a long-term short circuit or open circuit state, a large amount of lead sulfate inside the battery will be adsorbed to the cathode surface of the battery, forming "sulfation" of the battery cathode plate. Since lead sulfate is an insulator, its formation will inevitably have a very bad effect on the battery's charge and discharge performance. Because the more sulfate formed on the cathode plate, the greater the internal resistance of the battery, and therefore the worse the battery's charge and discharge performance. As the battery storage time increases, the actual capacity of the battery decreases to varying degrees. The higher the storage temperature, the less residual capacity of the battery. In order to ensure that the battery is always in good working condition, the battery that has been shelved for a long time must be charged once at a certain time to achieve the purpose of activating the battery and restore the original capacity of the battery as much as possible. Similarly, for UPS power supplies with high power quality and rarely power outages, the input of AC power should be artificially interrupted at a certain period of time to discharge the battery in the UPS power supply once, but not completely. It is best to discharge between 30% and 50%; then add the mains power to recharge. This operation is conducive to extending the service life of the battery and ensuring that the actual capacity of the battery is very close to the nominal capacity of the battery. If the battery is not allowed to perform any charging and discharging "operations", it is possible that the battery will be permanently damaged due to exceeding its storage life. This is why the service life of a newly purchased battery that is not used for a long time is shorter than that of an old battery that is often in a charging and discharging working state.