Please perform the following steps to resolve the issue:
For battery drainage issue follow the given link: http://www.samsung.com/in/support/skp/faq/1101689
1- Camera > Settings of camera > Reset of camera settings.2- Settings > apps > tap on 3 dots > show system apps > camera > storage > clear cache and clear data.
For further assistance, register your concern in Samsung Members Application (Open Samsung Members Application > click on “+“icon > send feedback > error report/ask questions).
Team Samsung Members