That would make it about three years old -- and that's nearing time lifespan of an original battery. You can run a report to determine the design and remaining charge capacity of the battery -- open a command prompt with administrator privilege and type powercfg /batteryreport If it's less than about 70% of the design capacity remaining, start budgeting for a replacement battery.  
a just bought a second hand laptop, its dell inspiron 15 7000gaming, and i checked that it has 38.99% battery wear level, last night my city had a maintenance so they have to cut electricity for 8 hours.   my laptop battery was drained, and i had to recharge it again, when i check the battery level, its around 42.39%   is there any way to prevent such a thing to happen again?
Battery wear level significantly increase