Here is how to build my Uber UPS Backup System on the cheap. First you will need to obtain a suitable UPS unit to start with, I recommend at least a 350 watt unit. I picked up mine at the Goodwill store for $6.00. After that it’s quite simple. Remove the stock battery, that is usually bad if you get one at a 2nd hand store like I did, and crimp on two quick release connectors to the red (+) and black (-) battery connection wires. Then do the same with the wires going to your new batteries. The wire size for the battery connection should be no smaller than 12 gauge for this project. I suggest that you always go male/female to the UPS unit and also on the battery cables so you won’t be able to accidentally reverse polarity. If you are using more than one battery like I am it’s also a good idea to put a in-line 10 amp fuse between the batteries for overload protection. For the batteries I use two AGM 35 amp sealed lead acid batteries. You should be able to get these from your local battery speciality store or if you live in the St. Petersburg, FL area go to Electro Battery where you can pick up a refurbished battery for around $25.00. I also recommend that you use your soldering iron and tin all of the wire connections for circuit reliability. When you are finished, put a load on the system and test it by unplugging the UPS unit from its electrical source. As always if you have any questions on this build you can contact me for assistance.