http://www.amazon.in/gp/aw/d/B00WG7GS56/
Features

• 5MP primary camera with auto focus, flash and front facing camera
• 4-inch (10.16 centimeters) WVGA capacitive touchscreen with 800 x 400 pixels resolution
• Windows v8.1 operating system with 1.2GHz quad core processor, 4GB internal memory expandable up to 32GB and Dual SIM
• 1950mAH lithium-ion battery providing talk-time of 8 hours and standby time of 240 hours
• 1 year manufacturer warranty for device and 6 months manufacturer warranty for in-box accessories including batteries from the date of purchase

Snapdeal also selling at Rs.2999
http://m.snapdeal.com/product/karbonn-titanium-wind-w4-4gb/652183976915

worst battery backup