The "XS 1500" refers to the APC Back-UPS XS 1500, an uninterruptible power supply (UPS) designed to protect electronic equipment from power surges and outages. 

Key Features and Specifications:

• Capacity: 1500VA / 865W, providing reliable power backup. 

• Automatic Voltage Regulation (AVR): Helps maintain stable power output during voltage fluctuations. 

• Outlets: Typically includes multiple NEMA 5-15R outlets for connecting devices. 

• Data Line Surge Protection: Offers protection for modem, fax, and DSL connections. 

• ENERGY STAR Certified: Indicates energy efficiency. 

• Battery: Uses a user-replaceable lead-acid battery, with a typical recharge time of 8 hours. 

• Runtime: Provides estimated backup time (e.g., 13 minutes at half load, 3 minutes at full load). 

• Model Number: Often associated with the model number BX1500G. 

It turns on and I can charge devices but I don't really know what to test for so I'm selling it as is for parts.