Intuitive LCD interface Provides clear and accurate information in multiple languages with the ability to configure the UPS locally with easy to use navigation keys. Predictive replace battery date Dynamically provides the month and year when battery replacement is recommended to aide in long term maintenance planning. Audible alarms Provide notification of changing flywheel conditions InfraStruXure Central compatible Enables centralized management via APC InfraStruXure® Central. SmartSlot Customize UPS capabilities with management cards. Cold-start capable Provides temporary battery power when the utility power is out. Serial Connectivity Use any Home Automation network to monitor and control the S20 through its RS-232 serial port. For information on how to communicate with the S20, see APC's Application Note #102. Crestron and AMX installers should visit their respective websites for information on how to integrate the S20 into those networks. Resettable circuit breakers Enables a quick recovery from overload events. Hot-swappable batteries Ensures clean, uninterrupted power to protected equipment while batteries are being replaced Disconnected battery notification Warns when a battery is not available to provide backup power. Automatic self-test Periodic battery self-test ensures early detection of a battery that needs to be replaced. Automatic restart of loads after UPS shutdown Automatically starts up the connected equipment upon the return of utility power. Adjustable voltage-transfer points Maximizes useful battery life by widening the input voltage window or tightening the output voltage regulation. Adjustable voltage sensitivity Provides the ability to adapt the UPS for optimal performance in specific power environments or generator applications. Audible alarms Provides notification of changing utility power and UPS conditions. User-replaceable batteries Increases availability by allowing a trained user to perform upgrades and replacements of the batteries reducing Mean Time to Repair (MTTR) USB connectivity Provides management of the UPS via a USB port (not available on all models). Serial Connectivity Provides management of the UPS via a serial port.