my phone trun off itself and the battery become empty itself

[Android Central Question]

my phone model is samsung galaxy A7 2016.for few day ago when my phone battery reach at percant of 30, it turn off itself and the battery become empty...n sometime when i charge it before reaching to 30 percent, i plug in the charger but instead of charging the battery become to go less till 1 percent and charge itself...why is this happening and what should i do?
PLEASE HELP ME...

 

[belodion]

One possibility is that the battery needs replacing.