Based on the specs, the line-interactive battery backup can correct for “brownouts and overvoltages from 83V to 147V.” So How will you estimate the power requirements with the system? The initial step is examining the core system and peripherals you want to carry on inside the function of power loss. https://sergioeeavr.blogminds.com/not-known-details-about-dc-power-supply-backup-31235227