Orison units have a maximum discharge rate of ~1.8kW (15A @ 120V, 7.5A @ 240V), at this rate a single unit would be depleted in less than 1.25 hours. It is very rare for this level of demand to occur in real life, below this maximum discharge rate Orison will operate to meet demand. For instance, if a modern refrigerator is the only appliance drawing on a unit it will take approximately three days before the Panel or Tower is depleted.
Also note that the units are expandable with the Tower+ and Panel+ units — up to five expansion units paired with a single master Panel or master Tower unit — so you could extend the discharge time at maximum rate to over seven hours if your needs required it.
Irrespective of whether it is a single master unit or a set that includes the expansion units, the Orison Panel and Orison Tower on a single circuit discharge at a maximum continuous total rate of 1.8kW (15A-120V). On a single circuit, you can combine a main unit with five expandable units for a maximum storage capacity of 13.2kWh, or additional main/expansion unit sets for more, albeit with the total 1.8 kW maximum output. If additional output is required, it is recommended that additional Orison units be installed on different circuits.