UPS battery maintenance status and solution

Necessity of UPS battery maintenance

In an uninterruptible power supply (UPS) system, it can be said that the battery is the backbone of this system, and a batteryless UPS can only be called a constant voltage stabilized (CVCF) power supply. UPS can realize uninterrupted power supply because it has a battery. When the utility power is abnormal, the inverter directly transfers the chemical energy of the battery into AC power, and the electrical equipment can be continuously operated.

At present, maintenance-free sealed lead-acid batteries widely used in small and medium-sized UPS power supplies account for as much as 1/4-1/2 of the total cost of UPS power supplies. Not only that, but actual maintenance also shows that about 50% of UPS power supplies fail. Related to UPS battery. Failure of the UPS battery is mainly due to insufficient terminal voltage, insufficient capacity, or instantaneous discharge current that does not meet the load start requirements.

Normally used UPS, its battery life is about 5 years, but at present there are a considerable part of UPS batteries in the country began to use less than 1 year to start problems, even worse, some imported brands of domestic batteries in the manufacturing process Congenital defects, on the other hand, are due to the lack of necessary maintenance. It is worth noting that many users of the system do not know the health of their own UPS batteries due to the lack of necessary testing and maintenance measures, leaving hidden dangers for the normal operation of the UPS system.

With five years of battery, must it not be used? Can a half-year battery be used? Is the battery provided by the UPS supplier good? --- The necessary inspection tool.

"A mouse, a bad pot of soup," more than ten batteries in series, as long as one section is damaged prematurely, if it is not discovered in time, it will take a long time and other batteries will be scrapped. -- Early detection.

A large number of UPS's failed, throwing away the first is an expensive battery, because the battery voltage is reduced for various reasons, and the maintenance person does not have the appropriate detection means. Thousands of tens of thousands of backup power systems have been established. Because of the uncertainty of the battery status, the system is paralyzed and important data is lost. The consequences are unthinkable. The huge losses are far from being compensated by tens of thousands of dollars.

State already knew!

Traditional UPS battery testing and maintenance

General UPS power requirements for the battery: to meet a certain terminal voltage; the battery should have the characteristics of a large current output at the moment of starting discharge; meet a certain capacity to ensure the time of inverter power supply.

1, using a multimeter to measure the battery terminal voltage

Practice has proved that using a multimeter to measure the float terminal voltage of the UPS battery can not determine whether the old battery has failed. Therefore, the terminal voltage of the battery is generally measured off-line or on-line. The terminal voltage of the battery under test is about 12V (for a 12V battery), and the minimum voltage cannot be lower than 10.5V. A battery less than 10.5V is undervoltage or has failed. If such a battery fails to reach 12V after charging or activating the charging back-end voltage, it is a dead battery.

2. Test whether the UPS battery has the characteristics of high output current at startup.

Backup UPS power supply from the mains power supply to the inverter power supply switching time requirements less than 7ms, generally designed to be about 4-5ms. This means that once the mains supply is interrupted, the UPS battery must output the current required by the load in less than 4-5ms. Some failed batteries can meet the requirements of terminal voltage and capacity, but can not meet the requirement of large current discharge current in less than 4-5ms, but also failed batteries. The characteristic that the UPS battery outputs a large current instantaneously can only be tested when the utility power is turned off. There is a certain risk without knowing the battery performance, and it is generally not performed.

3, determine the UPS battery capacity

The traditional way of judging the capacity of UPS batteries is the same as the method of judging common batteries. The entire battery group is disconnected from the communication power system and connected to a resistance wire, discharges at a constant current of eight or ten hours, and then arrives at the discharge termination voltage first. The discharge time and current of the single battery are used to calculate its capacity.

Traditional capacity testing has the following disadvantages:

(1) The battery pack must be removed from the system to increase the risk of system crashes;

(2) The discharge time is long, manual test records are required, and the workload is large. In addition, the UPS battery is generally installed in a box cabinet, and the test work is not easy;

(3) The resistance wire is bulky and has red heat, which is unsafe and the work intensity is great.

Domestic UPS battery maintenance status

The maintenance of the UPS battery is similar to the maintenance of the general low-voltage system battery. When a new battery is introduced, it is required to be accepted by the project, and the internal resistance and voltage of the battery are tested simultaneously to ensure the consistency of internal resistance; when the new battery is put into use, it is required to maintain Appropriate battery operating ambient temperature requires periodic measurement of each battery terminal voltage and internal resistance. When the internal resistance or differential pressure of each battery is too large, uniform charging is required, and the battery is deeply discharged periodically to check the performance of the battery pack. Bad and keep battery activity.

However, in practical applications, due to the limitations of various conditions, the maintenance of UPS batteries is rarely performed exactly as described above. First, new batteries are accepted. Since there is a long time, there is no convenient tool to use, and quite a few people do not have them at all. Doing this work will put the battery into use. According to statistics, about 95% of the UPS batteries in the Chinese mainland lack the necessary maintenance, which lays a hidden danger for the future UPS power supply failure; secondly, after the new battery is put into use, due to the general UPS battery Is installed in the cabinet, measurement, from the inconvenience, rarely measure the internal resistance and terminal voltage; according to the existing conditions (98% of the UPS battery is not installed monitoring equipment), the majority of maintenance personnel can only perform every other period At the time, shutting down the mains power to allow the UPS battery to discharge to the actual system for a period of time. At best, it only activates the battery pack to maintain the battery's activity. However, it is not possible to know important data such as the battery performance and the remaining capacity of each battery.

UPS battery maintenance comprehensive solution

Smart battery status test analysis system

How to establish an effective maintenance and management method for valve-regulated lead-acid batteries has always been a concern for maintenance personnel. Recently, Shenzhen Proke Intelligent Detection Equipment Co., Ltd. has launched a comprehensive solution for battery maintenance, which solves the current lack of necessary maintenance tools and tools for UPS batteries. It can not only test the battery performance, but also look for backward monomers, as well as batteries. Early forecasting is effective to prevent failures and has good results. This is especially recommended to users to help establish an effective battery maintenance method.