I've got something similar, from Trust (bought in Makro in Palma). It can't support the computer, modem and screen together for nearly so long as it claimed. It will support the computer on its own for over half an hour but that's not much use if the power is off for longer as you can't see to close everything down before the battery goes flat.
It uses a little 7.2ah sealed lead-acid 12v battery which ceases to function after a year or so because of the very crude charger in the machine. I opened it up and removed the little internal battery and made a connection to a golf trolley battery which I sit beside the thing. That worked quite well for a while until the crummy charger stuffed the new battery as well.
I quite like that the machine protects the power supply AND the incoming comms. line from surges which might damage all my kit and the router as well so I'm thinking about cutting out the built-in charger and using a fancier golf trolley charger(!). God knows what my insurer would say if he knew!
Mine came with no software whatsoever - one just has to connect the incoming leads to the box and then connect the box on to the computer kit. Simples!