shut down at 50 percent

Hi my name is Tasia Hester

My Hewlett Packard computer shut down at 50 percent at 9:37 p.m. tonight on Friday August 18 2017,

Can somebody please help me with this problem. I had this computer since December of 2015 with the low battery notification until Wednesday June 7 2017 my computer turned off which was the start of my problems which never happened before all last year until this year for some reason.

I tried device manager tonight to try to fix the problem but it did not work and I tried multiple times to change the battery to show low battery notification but that didn't work,

I just want somebody professional to help me because this is annoying