Why mi iphone turned off when take photo even if have more than 50 of battery

Hi everybody, I have a little problem with my iphone 4s 32gb, whe I try to take a photo, the cell phone turns off without any previos message, It just put the black screen, and when I try to turned on again, the cellphone is completely uncharged; but, when I connect the cell phone with the charger, it appears with charged battery. Is it a problem with my battery? or is it a software problem? Thank and sorry for ortographic and grammar mistakes. I live in Mexico : )