I had purchased Luminous Eco Watt 700 VA invertor and Luminous tublar battery in March 2013.
It's being more than 4 years now.It's working fine n gives same backup.In my area there are lot of fluctuation in electriciity but with the auto cut features it will automatically switch to battery mode which saves my electric appliances which are connected through invertor.
No heating issue, no sound while charging, no sound in Fan while on invertor mode.
You don't need UPS for your desktop computer.Invertor UPS mode available when you require just on it from back of invertor pannel.
For better performance you just need to make sure to check water level within 2 months because it impacting invertor.
During 4 years I spend only Rs 150 for fuse exchange of invertor that's it.
Customer service is good .They will take 24 hrs to process request.
Overall there was nice expierence with this product.
