Review on 🔌 Reliable and Versatile Liebert PSI5 UPS - 1500VA 1350W 120V 1U: Rack Mount Line Interactive AVR Sine Wave UPS with Surge Protection and 0.9 Power Factor by Chris Hunt

I have a couple of old Liebert UPSs that use VRLA (gel cells) batteries, but they don't last long and never seem to have enough charge when I need them for work. Just a day after installing this new lithium-ion pack, there was a momentary power outage of about 10-15 minutes and my computer and networking gear continued to run fine. I will never go back to lead acid batteries! Another nice feature is that the lithium block is noticeably lighter.