Lenovo — Battery died after 8 months.

I bought Lenovo yog2 11 on August in US at the best buy shop at Pentagon City. Last week the laptop indicated battery is weak and needed a replacement. I did not take it seriously as i rarely use the laptop and use it only for personal matters. Is this normal? was there a problem with the battery? i expected the laptop to serve me for at least three years before the battery life ends. Kindly advice.