After more than 1 year of using and testing a 1000VA UPS at my station, I offer the following:
1. The 1000VA UPS is 24VDC, comes with two 12V 6AH batteries, runs 10 minutes max at full load.
2. Remove the internal batteries and install 2 deep cycle marine batteries externally. Install muffin fan to push cool air into the now mostly empty box.
3. Now powers my full station for more than 8 hours at a 50% duty cycle of TX/RX.
Station has Ten-Tec Jupiter and associated equipment powered by 1 MFJ 4225 Switching power supply. 1 Laptop computer, two line phone, 15 inch TV, desk lamp, a second MFJ 4225 switching power supply feeding an Alinco DR 135, DR 435 radio's. More than long enough to get my generator connected to power the Ameritron AL-811H Linear if needed. The UPS just powers the station equipment and is one heck of a Surge Protector on the power line. BTW I use one of the small 300watt units to feed my power supply at Field Day, you know the generators are more problematic at that time.
Good Luck Steve W4CNG