I am using this invereter and battery since 1 year.it is not working properly now and has backup till only one hour and this for only 4 bulbs and 3 fans when I bought this product they told me that it can last up to 8 hours but that was false and has only back up less than 2hrs. and it is not user friendly and it give backup for very less time and totally waste of my money and I contacted service centre also and they also not responding.