Extended-runtime lithium-ion battery pack provides much higher energy density and scalable runtime to Smart-UPS applications. The APC Smart-UPS On-Line Lithium-ion Extended Runtime Battery Pack offers flexible rack and tower installation options and provides 3X the battery life when compared with a VRLA battery. Compatible with SRTL 1-3kVA systems, this versatile 2U long runtime battery is perfect for critical long runtime applications in network IT and other applications.