I have a 2005 Dodge stratus R/T and about month ago when driving to work i noticed the brake light, battery light on dashboard and the headlights blink faintly fast for couple seconds then goes off. Car starts fine and only notice it once a day but happens everyday on way to work, or best i can tell since it is a faint light and i can see it when dark out. I drive 45 minutes to work in dark so notice it only once per day and not always same time into drive. I had charging system checked and the wires to altenator checked. No loss of power or hard starting but just annoying and wonder if going to just die on me some morning.
Make sure all connections are clean and tight, including the grounds. Sounds as if the regultator in the alternator is going bad.
@kfenimore: There is no regulator in the alternator. Charging is managed by the ECU on this car and pretty much every car since the early 90s. But I agree that the battery connections should be checked for tightness and corrosion.