OK - Safety First This hack involves working with batteries and electrical equipment. Batteries are full of acid and can produce currents of hundreds of amps which can lead to burns, fires, explosions, and generally unpleasant outcomes. Electrical equipment can kill you. Plus this most definitely voids your warranty. Don't try this at home kids. So here is the donor patient, a Socomec NETYS 2000VA/1200W Home UPS that comes standard with 2 Internal 12V 9Ah batteries connected in series. At 50% load, which is about what I will have on it most of the time, that will give you about 20mins runtime. It has an inbuilt cooling fan that runs when the inverter is supplying 240V from the batteries. It is now going to have a pair of 18Ah deep cycle batteries to double my run time to ~40 mins. As you can see the new batteries will not fit inside so the cables have to come outside. This was easy enough to achieve with this model by drilling a hole in the side of the case and pulling it through. Other models of UPS will require you to solder in additional cable. The new batteries also have different terminals than the originals so the old connectors have to go. Crimp on some new ones that are compatible with the batteries. Connect the new batteries in series just like the old pack View attachment 20161223_135659.jpg Then hook the whole thing up and turn it on. From reading the results of other UPS hacks around the web it generally isn't a good idea to load up a franken UPS beyond about 50% of it's rated power. Often the cooling in them is only rated to provide full power for the standard run time, and attempting to keep full power up beyond the standard runtime can result in meltdown. Also consider the battery size vs the charger in the UPS. Sure you can hook up 1000Ah of batteries to your little UPS but it will not be able to recharge them when they have been run down.