Lenovo IdeaPad Z410 Battery Suddenly Drops From 100% to 0%?

Have been using Ideapad Z410 from past 6 months. From past week the Laptop shuts down without warning, and the battery level is at 99% or 100%. Only when the unit shutdown suddenly, and when I start up again, that the battery indicator starts from 0 and goes to 99% or 100% and stays there.
What is the problem, and what should I do?

Hi time to consult with a tech about this it could be a variety of reasons.