How about your belt tensioner? If thats going you may not be getting quite enough out of your alternator. if you have a volt meter you can check the voltage at the battery yourself, when everything is off your battery should be around 12.6-12.8. When the engine is running you should be around 13.6-14.0. The battery light will also come on if you are over or over a normal voltage range. If you are under your abs light, and brake light will sometimes come on. If you are way over your check engine light will come on.