Battery power supply time is mainly affected by load, battery capacity, ambient temperature, battery discharge cut-off voltage and other factors. Generally, when calculating the power supply time of UPS battery, the battery discharge current can be calculated, and then the discharge time can be found out according to the battery discharge curve. The battery discharge current can be calculated according to the following empirical formula

Discharge current = UPS capacity (VA) × Power factor / average battery discharge voltage × efficiency

To calculate the actual load discharge time, just replace the ups capacity with the actual load capacity.