Opti UPS ES1500C-RM Enhanced Series 8-Outlet Rackmount Line Interactive Uninterruptible Power Supply Rack Mount, AVR 1400VA / 980W UPS battery backup system, Uninterruptible Power Supply (UPS) 3 year limited warranty / live US support Line interactive  corrects voltage without using battery power, Connectivity - interface Port DB-9 RS-232, (USB optional) 1050 joules surge energy rating to prevent damage from power surges or spikes, simulated sinewave design Internet/LAN (RJ11/RJ45) surge protection, AVR (automatic voltage regulator), 8 battery backup outlets, Scheduled shutdown &amp; reboot Easy battery replacement procedure, 4 hours battery recharge time, Smart power management software (included) Transfer time 4 ms, LED display- shows UPS operating status, history record of power failure events, free OPTI-SAFE sentinel software Advance Warning-Front Panel: AC Mode/Buck/Boost/Battery Mode/ Battery Fault, Extended battery run time  2 internal batteries