Charge mode: 25V input/ 20~30.6V @3A Discharge mode: 21~30.6V input/ 24.3V @16A When system voltage drops down below the preset output voltage (24.3V nominal), the UPS is required to switch into discharge mode immediately to take over and drive the load, making sure its output voltage is within regulation. The discharge shall stop driving the load once the output voltage is above the preset 24.3 V UPS output voltage and go back to standby mode or charge mode.