Yes, you should. Turning on the ignition without your car starting can be quite a frustrating experience. This is what you get most times waiting until your battery dies. You don't have to leave the battery until it eventually dies before getting a replacement. Batteries usually show some telltale signs once they begin to decline. Whenever you notice any of these symptoms, it is best to get a replacement. A general rule is to consider replacing your battery once it exceeds three years.