Why did My battery light come on while I was driving?

My light did the same and I had a nervous moment given the cold weather etc...On my MOPAR vehicle there is a sensor (overheat condition) beneath the battery tray and after tightening the battery holders and driving for a bit, it turned on. My fix was cleaning terminals and tightening connectors.\ You might want to check that sensor if after tightening and checking the condition of the battery doesn't remedy.

Vehicle was not charging the battery like it should. Check battery connections, battery cables and the alternator. Something needs maintenance...

Have the alternator output checked!!!!