Hi - new here but need some advice. My mother is on an oxygen 24hrs a day - the oxygen concentrator is a 700W unit. To date i have been through 2 systems - the first was a deltec inverter with a Deltec 12V 200Ah AGM battery - this lasted less than a year and cost us about R10k - the place i bought it from, MAL Batteries then told us there was only a 3 month warranty and tried to sell me a small mobile system for R15k. I then bought a new inverter from Rubicion and a Mecer LiFePO4 12.8v 200Ahbattery. this has lasted just over a year and the battery doesn't last a half hour during load shedding - of course the battery has a 1 year warranty - which expired last month!! I really need to get a proper reliable setup that could possibly also run her DSTV and TV while the electricity is down. If there are any experts out there that could point me in the right direction it will be greatly appreciated