Your last statement is true for home users. In a corporate environment UPS's are used to carry the load of our equipment until our generator starts up. There is a 5 second delay between the power going out and our generator coming online, the UPS will keep our equipment up and running during this switch over to avoid any data corruption or hardware failure.
Likewise this statement should stand true for home users. Knock on wood I live in a newly developed neighborhood all of our transmissions are ran underground, this does help in the event of a disaster but we still have experienced power outages. In the 5 years I have been in my new neighborhood we've lost power a few times with the longest outage being 10 minutes. The various battery backups I have around the house can easily handle the load for 10 minutes. This means that none of my tank equipment, PC or networking equipment along with my tv's never see the power go down or come back online. Now with that being said next year once my tank is stocked I will be investing in a generator. The UPS will allow me enough time to get the generator online if there is a potential long term outage.
Ecotech does make a battery backup that according to their specs will run a pump for 36 hours with 1 MP40 and 18 hours with 2 MP40's per their documentation. You can also daisy chain their backups to one another to double the run time. This is very well a viable solution if anyone is running vortech pumps.