UPS Battery Life: Service life of machine room UPS
UPS
The full English name is Uninterruptible Power System/Uninterruptible Power Supply, which is a kind of uninterruptible power supply with energy storage device and inverter as the main component. It is mainly used to provide uninterrupted power supply for a single computer, computer network system or other power electronic equipment.
working principle
When the mains power input is normal, the UPS is used as a voltage regulator; When the mains power is interrupted (emergency power failure), UPS provides continuous and stable 220V AC power through inverter conversion to maintain the normal operation of computers, computer networks or other power equipment for a period of time.
application
UPS has been widely used in aerospace, industry, communications, national defense, hospitals, computer networks, transportation and other fields, and is an important power supply guarantee equipment for enterprises.
How can such an important UPS improve its working quality and extend its power life?
First, let’s learn about the service life of UPS.
The service life of UPS depends on the operating environment and maintenance. Normally, the service life of the UPS power supply can reach 8-10 years, while the properly maintained UPS power supply can be used for more than 15 years. For example, the data centers in many parts of the United States have been used for about 20 years, and the UPS power supply inside has never been replaced. However, in actual use, the service life of UPS is usually only about 5 years.
So, how to effectively maintain and extend the service life of UPS?
Maintenance UPS
(1) Perfect maintenance conditions (ideal condition)
UPS machine room should be air-conditioned and anti-static floor room, with good lightning protection effect, dust-proof, moisture-proof and sunscreen.
The input voltage is within the design range, and the most reasonable load range is 30% – 60%. Maintain at least once a year.
In reality, it is difficult for us to do so, so we should try our best to master some common sense of maintenance. For example, prevent dust accumulation in the case, and regularly maintain the battery in the power supply.
(2) Maintain appropriate ambient temperature
Generally, the best ambient temperature is 20-25 ℃. According to the test, once the temperature exceeds 25 ℃, the battery life will be shortened by half for every 10 ℃ increase. In addition, the increase of the ambient temperature will lead to the enhancement of the chemical activity inside the battery, generating a lot of heat energy, which in turn will promote the increase of the ambient temperature and enter a vicious cycle.
(3) Periodic charging and discharging
We have known before that the working principle of UPS is energy storage – inverter – AC power supply. We can think of it as a battery. If the battery is in a long-term floating charge or discharge state, its life will be reduced. Therefore, it is better to fully discharge once every 2-3 months, and then charge for more than 8 hours as required after discharge.
(4) Use communication functions
The intelligent communication function can greatly facilitate the use and management of UPS power supply and its battery. Most large and medium-sized UPS have the performance of communication with microcomputer and program control. By installing corresponding software, we can query UPS related information, parameters, setting timing, automatic shutdown and alarm on the PC.
(5) Replace the waste/bad battery in time
The number of batteries equipped for large and medium-sized UPS varies from 3 to 80. Therefore, when individual batteries are damaged, the overall DC power supply of UPS will be affected. Maintenance personnel shall check each battery and replace it with a new one. It is prohibited to use batteries of different amperage and different brands in combination.
Extend UPS life
(1) Use of AC voltage stabilizer
After using UPS power supply, it is unnecessary to add AC voltage stabilizer. If it is necessary to add it, it should be added to the front level of UPS power supply, that is, the mains power first passes through the AC voltage stabilizer, then through the UPS power supply, and then to the load.
(2) Avoid overload and use UPS power supply
When using the UPS power supply, the load should be calculated to avoid too large or too small load. The reasonable load should be controlled between 50% and 80%.
(3) Try not to overload operation
In general, the load of online UPS should be controlled at 70%~80%, and the load of backup UPS should be controlled at 60%~70%. Note that it is not good to overload too lightly, although it is not as serious as overload.
(4) Do not use the diesel generator
UPS power supply should not be powered by diesel generator, because its frequency is often abrupt and unstable, affecting the normal operation of UPS power supply.
(5) Power on and power off sequence when using UPS power supply
The correct startup and shutdown sequence should be to turn on the UPS power supply first, and then turn on each load, so as to avoid the damage to the UPS caused by the transient current impact during startup; The order of shutdown is just the opposite.
(6) Tips for first charging of UPS power supply
The newly purchased UPS power supply shall be plugged into the 220V municipal power grid for charging at least 12 hours to ensure full charging.
(7) UPS power supply cannot be idle for a long time
Excessive discharge of the battery and long-term open circuit idle of the battery will increase the internal resistance of the battery and deteriorate the charging and discharging performance. If the UPS power supply is not used for a long time, it should be turned on for 24 hours every 2-3 months, and the UPS power supply should be kept under inverter operation for 2-3 minutes to ensure the normal life of the battery.
(8) Battery management skills
The batteries (VRLA) used in many UPS power supplies are called maintenance free batteries, which gives users a misunderstanding that such batteries do not need maintenance. In fact, if the terminal voltage is lower than the specified calibration voltage of the battery in the UPS power supply due to excessive discharge, the battery shall be charged evenly.
(9) Real time monitoring
Use the communication function to monitor the UPS power supply in real time on the microcomputer.
(10) Reasonably select the installation position of UPS power supply
The place where the UPS is placed must have good ventilation effect, be far away from water, combustible gas and corrosive agent, and the ambient temperature is between 0~25 ℃. The UPS power supply should not be placed sideways, and the air inlet and outlet should be kept smooth.
epilogue
Regular maintenance of UPS power supply is very important, which can not only keep UPS in good performance and prolong its service life, but also guarantee the safe use of electricity and power supply for enterprises.