Have Mercedes Questions? Ask a Mechanic for Answers ASAP
Hello, my name is ***** ***** I am a professional here at Just Answer. I have noticed that your question was not getting a response and thought I would see if you still need help with this.I apologize for the delay and I hope I can still assist you with this here.The battery light in most cases come on due to a problem with the charging system and not the battery. In order to determine the cause you are going to need to do some test which includes the alternator. I have enclosed the things to check in the link below, copy and past the link to your browser to open and view them.https://dl.dropboxusercontent.com/u/104923897/ALt%20test%20Oct%2013.pdf
The battery light is controlled by the alternator so yes, have the charging system tested .