Is this specific to Lithium battery UPS units? For home use I bought a lead acid UPS specifically to avoid a fire. For a 5 hour power outage it makes no differ

Is this specific to Lithium battery UPS units? For home use I bought a lead acid UPS specifically to avoid a fire. For a 5 hour power outage it makes no difference to me if the UPS powers my machine for 5 minutes or 20 minutes; as long as I can save my stuff and shut down it works for me.