A man builds a robot to be his teen or pre-teen son. The robot needs to have his 'battery' changed at night. I think eventually the robot starts to feel emotions. I think it would have been in the 70s or 80s.

Not Quite Human (http://www.imdb.com/title/tt0093649/)?

I Robot

Could you be thinking of; A. I. Artificial Intelligence?

Artificial Intelligence: AI (2001) (http://www.imdb.com/title/tt0212720/) Spielberg