Woot offers Refurbished  CyberPower CST135XLU Battery Backup for $79.99. Free shipping for Prime Members.

Product Description:
A mini-tower UPS with line interactive topology, the CyberPower Intelligent LCD CST135XLU provides battery backup (using simulated sine wave output) and surge protection for desktop computers, workstations, networking devices, and home entertainment systems. The CST135XLU uses Automatic Voltage Regulation (AVR) to correct minor power fluctuations without switching to battery power, which extends battery life. AVR is essential in areas where power fluctuations occur frequently.
Two USB charge ports (2.1 Amp shared) rapidly power portable devices such as mobile phones, MP3 players, and cameras.
Product Features

• Battery Backup: Supplies power long enough for equipment to properly shut down when utility power fails. Helps prevent loss of data and minimizes the component stress caused by a hard shutdown.
• Surge Protection: Diverts excess voltage away from sensitive electronic equipment during an AC power surge or power spike to prevent damage.
• Data Line Protection: Prevents power surges that travel through telephone, coaxial, and Ethernet lines from causing damage to electronics.
• Line Interactive Topology: Exists when a line interactive UPS has an autotransformer that regulates low voltages (e.g., brownouts) and over voltages (e.g., spikes) without having to switch to battery.
• Automatic Voltage Regulation (AVR): Provides clean, consistent AC power by automatically regulating low voltages and over voltages, within defined tolerances, when incoming utility power has minor fluctuations.
• Simulated Sine Wave Output: Uses pulse wave modulation to generate a stepped, approximated sine wave to supply cost-effective battery backup power for equipment that does not require sine wave output.
• USB Charge Ports: Rapidly charge and power USB devices such as tablets (including iPad), smartphones, MP3 players, and other mobile accessories.
• GreenPower UPS™ Bypass Design: Is a patented design that allows utility power to bypass the UPS transformer, when AC power is stable, which reduces energy consumption, noise, and heat buildup.
• Multifunction LCD Panel: Displays immediate, detailed information on the battery backup and power conditions, alerting users to potential problems before they can affect critical equipment and cause downtime.
• Ultra Quiet Design: Minimizes noise during operation for a quieter work environment.
• PowerPanel® Personal Edition Software: Provides a user-friendly dashboard interface for controlling and monitoring the UPS. Free software download available. See the Resources tab.
• ENERGY STAR: This model is an ENERGY STAR® certified Uninterruptible Power Supply (UPS) system. ENERGY STAR is the trusted, government-backed symbol for energy-efficient products and practices that help save money and protect the environment.
• Connected Equipment Guarantee: CyberPower will repair or replace properly connected equipment if it is damaged by a power surge

Typical Applications:

• Desktop Computers
• Workstations
• Home Theater Equipment
• Personal Electronics
• Home Networking
• VoIP Phone Systems
• Automatic Voltage Regulation