I have purchased this to power it via a solar power battery and it worked great for about 7 days. For a 600w unit, on ECO mode, it would make it through the nigh for only 10-30 % of the battery capacity. On the 8th day of my trip, the temperature would not go below 8-9 degrees although it was set on 4 and the inside temp of the fridge was almost freezing and all my battery empty in about 1 hour. I am not sure, but could this be caused by a faulty thermostat? Everything else is great, good build quality and design. Please let me know if there is some way to fix it.