UPS Power
Hi,
This may be due to damaged battery or damaged parts. If it is due to the battery, then you can change the battery, and you need to ensure that your UPS has high and low cuts, which means charging is cut off or battery is float-charged after it reaches a specific voltage, and the inverter is switched off before it is totally discharged (at a specific battery voltage).
If it is due to damaged parts, then you need to locate the faulty parts and replace them. This however could get complex.
Hope this helps.
Tahmid.
Added after 45 seconds:
And you need to make sure the battery is charged within a specific voltage range (not too high voltage or too low).