why does my battery light keep coming on on 2001 Ford Escape

the battery light seems to come on after driving the vechile for a while with heat on.

Asked by for the 2001 Ford Escape
it could be a few things, your battery needs to be replaced take it to an auto parts store they can check your alt/battery for free and let you know whats going on there, if they are fine take it to a shop to have an electric test ran