External Li-ion battery pack with up to 10 years of service life For APC Smart-UPS SRT Li-ion 1 U SRTL2K2RM1UIC or SRTL3K2RM1UIC Incl. feet and rack-mount kit Weight: approx. 12 kg A total of max. 5 battery packs can be connected Additional runtime: 3000 W load: + 15 Minutes 2500 W load: + 18 Minutes 2000 W load: + 21 Minutes 1500 W load: + 27 Minutes 1000 W load: + 40 Minutes