I've rooted it and changed a file so if it's run out of power as soon as a power source is detected it turns on. If it's still got battery erobot handles it. So if power detected power on screen, wifi, bluetooth and gps. If power source is lost its runs an application called screen of as well as powering down the wifi,gps and bluetooth.
I was using this fine but I've changed to a bluetooth version so I can hook my pad up to my phones hot spot
Old worked fine - http://www.amazon.co.uk/gp/product/B011O69946?psc=1&redirect=true&ref_=oh_aui_search_detailpage
New - http://www.amazon.co.uk/gp/product/B00UR5BRZU?psc=1&redirect=true&ref_=oh_aui_search_detailpage