My Lenovo IdeaPad Z510 is having charging problems?

My Lenovo IdeaPad Z510 is having charging problems. This started just around 3 days ago. My charger will be plugged in for a long time and my laptop will tell me that I have 99 percent or 100 percent but not even a minute after I unplug it from the charger, it will shut down and the battery life light will start to blink. I don't understand what is going on.

Dead/dying battery (not in power, I mean its actually dying)