One of my friend has been installed this kten marathon inverter. I am sharing his experience in this review which makes me to take right decision. he told me that he bought this inverter and installed in his house. he told that the average battery backup time is two to three hours which is different from the paper side mentioned four hours. also some time the inverter did not maintain the voltage supply and bulbs got fused. he recommend me to not to use this inverter. so I had decided to buy luminous inverter which is trusted and efficient as well.