Worked OK while it worked, but no warning that battery was dying or dead. Tripp Lite website has nothing about replacement batteries, what to get, how to get it, or how to replace it. The manuals available for download on the Tripp Lite website are generic, apparently applicable to all Tripp Lite UPS units, with no photos or specific instructions about the OMNI1000LCD, nor, as I said, ANY info re: battery replacement.My recommendation: LOOK ELSEWHERE. (My replacement for the TrippLite OMNI1000LCD, with which I am very happy, is a CyberPower CP1350PFCLCD UPS 1350VA 810W PFC Compatible Pure Sine Wave, comparable price, better performance, pure sine wave.)