In that case you would need about 100kWh of battery capacity! Modern lithium batteries cost around $750 per kWh so just the battery alone would cost around $75K. Then you would need the multi-mode inverters and other equipment.
Basically you would need a powerful off-grid inverter to be able to charge battery of that size and enable backup power. These inverters can be used without solar and setup for backup power. In Australia Selectronic is the best option, but in the US, the high-performance inverters from Outback Power or SMA would be a good choice.
As for batteries, the best options are the same as those used for off-grid systems. Simpliphi is a well known, high-end battery made in the US.