An uninterruptible power supply (UPS) is very useful in ensuring continuous power supply to electronic devices when the main power source goes out. A UPS features a battery where power, used to protect against power failures, is stored. While there are several factors affecting battery life, the lifespan of most UPS batteries ranges from three to five years. When it becomes necessary to replace the battery, the “replace the battery” light normally comes on.
But, there are instances when the light would come on unexpectedly even though the battery has not yet reached the end of its lifespan. These situations normally happen when the self-test fails. A self-test checks the attached load of a UPS by switching its power source to the battery.
To check whether the battery is still good or not, the UPS should be unplugged from the external power source and the UPS is allowed to run on the battery. If the voltage of the battery goes down drastically, the battery will have to be replaced.
But, if the voltage remains constant, the UPS should be turned off completely. This can be done by removing the attached load, unplugging the UPS and disconnecting the battery. Then the “on” button of the UPS is held down for five seconds before the battery is reconnected. The UPS is then plugged into an external power source. After this, the UPS can be switched on.
There are also instances when the light turns on after the battery of the UPS is replaced. To clear this status, it is necessary to ensure the battery is fully-charged before running a valid self-test.
To make sure the battery of a UPS reaches its optimum life span, the UPS should be positioned in a cool and dry location. It is also important to keep the load on the UPS under 80 percent of the rated capacity of the battery to increase its lifespan.