A UPS contains batteries.

A UPS, or Uninterruptible Power Supply, is designed to provide backup power to electronic devices during power outages or fluctuations. A critical component of a UPS is its internal battery system, which stores electrical energy. When the main power supply fails or experiences disturbances, the UPS draws power from its batteries to continue supplying energy to connected devices. This capability ensures that equipment such as computers and critical infrastructure can keep running uninterrupted, preventing data loss and potential damage. Therefore, claiming that a UPS contains batteries is accurate, as the batteries are essential for its operation and primary purpose.