Q: iPhone 5s crashing with plenty of battery and have to reset to turn back on.

hi guys,

for or the last 6 months or so my 5s has been randomly crashing and in order to turn the phone back on I have to reset it. It happens most days and happens no matter how much battery life is left. Will sometimes happen repetedly, one after another. It only happens when the screen is locked (never happens while I am actually using the phone). I have checked the serial number for the faulty thing but it didnt come back with anything. Have also been through multiple ios updates and still no different! Any help you can give is appreciated- as it is starting to drive me crazy- the phone isn't even a year old!