Possibly a battery problem, or it could be an issue with the alternator not charging it properly. Worth getting them both checked.

You don’t want to be like me and have the alternator completely die suddenly while you are driving home from work and end up stranded on the side of the road for hours on a stupidly hot and humid day in the middle of a thunderstorm, on a Friday evening so that nothing can be fixed until the next week and you have to wait hours longer for a tow truck.