APC ES 350 u (2001 model) 200 watt 350 va ups with a huge battery upgrade. The stock 3.4 amp hour battery in my ups could only run my small office setup for a pathetic single minute. This did not work well for me, since my windows computer takes more than 1 min to shutdown (thanks to random updates and constant errors) and since I lost the usb data cord to communicate with the ups over 5 years ago. Typical replacement batteries for this unit ranged from $30 - $40 depending on where you buy them. Since these batteries were never designed to handle the type of load that a desktop computer throws at them, they usually breakdown within a year or so and so on. I decided after watching many youtube videos on solar setups and a few on people that also decided on a bigger ups battery, to do the same. I now have a ups that is capable of running my desktop for 7.5 hours if I deep cycle the battery or 4.5 hours if I leave 40% reserve. The battery I selected was a walmart brand everstart maxx 125 ah deep cycle battery, which is heavy but will save me money in the long run on replacement apc batteries. I expect this battery to last anywhere between 4-8 years before I have to replace it. Just some extras on the battery, it is capable of running 1500 watts for one hour, but the most I will probably ever pull out of it is 400 watts, via an external power inverter. In order to connect the battery to my ups, I had to modify the ups’s battery door to run some extra wiring and place the …