Modern cars absolutely hate a battery that is not holding charge properly or not fully charging in the first place. If the computer and the various sensors around the car aren’t getting the correct voltage form the battery, they can decide to shut down or go slightly crazy, causing rough running, poor fuel consumption and hard starting (to name just a few symptoms).
A radio playing on a job site really shouldn’t flatten a battery in a few hours, but are you leaving the doors open and, therefore, the interior light on at the same time? That could definitely flatten the battery. The rule of thumb is that you should expect about five years from a battery, so on that basis, yours is definitely a chance to be ready for replacement. Test the battery under load (when cranking the engine) to see how much current it’s delivering under stress.
