https://www.eaton.com/au/en-gb/products/backup-power-ups-surge-it-power-distribution/backup-power-ups/different-types-of-ups.html#:~:text=Differing%20from%20an%20offline%20UPS,power%20and%20the%20backup%20battery.
Line-interactive UPS
The line-interactive UPS combines features of both the offline and online UPS. It is designed for power conditioning and to manage under and over-voltages of 20% from the standard voltage. It involves AC power being passed through a regulator: this corrects any abnormally low or high voltages. During these abnormal voltage occurrences, the battery is not in use and is being charged until it needs to back up the power source. Line-interactive UPS systems are suited to areas where there are rare occurrences of outages but voltage fluctuations are common.
View Eaton’s Line-interactive UPS range which includes the 5E, 5S, 5P, 5SC, 5PX, 5SX models.