If you mean the battery light is on then its possible the alternator is at fault .This means the battery will not be getting charged , but its not a serious problem ! First have the battery & alternator checked at your local garage ( 5min job ) to confirm. If it is the alternator then a new one will be expensive so try a breakers yard for a second hand one , or cheaper still an auto electrician may be able to repair yours . Hope this helps !
Glynn, November 2009
