Hello Kaushikvatsal,
I would suggest few steps would which would help us in isolating the issue further:
- Check the Battery Health in the BIOS. To enter BIOS Setup, restart the computer and keep tapping F8 key at the Dell logo screen. Check the battery health and make a note of the message. If anything other than your battery is "performing normally", the battery should be replaced.
- Dell offers a free Battery Diagnostic test, to run the test refer to the Dell Battery Diagnostics site.
- Also try the suggestions mentioned in article on How to improve your laptop battery’s performance.
For more details, see Laptop Battery FAQs.
Hope this helps!