Hello everyone
When I'm going to sleep I'm used to turn off Wi-Fi, 4G and everything except cellular network, and when I got my iPhone 5S (about 15 days ago) I did the exact same thing at bedtime.
Since the first day I noticed that on stand-by, the battery ran out about 15-20% per hour, so I called to tech support but they told me to restore the phone, to deactivate everything and stop enjoying my 1,000 USD cellphone, and actually made fun of me, telling me "Yeah, I would like my cellphone to be alive all day long, too, but we're not God", so I went to the store a few days after.
They told me to leave the iPhone and they would check if there was something wrong and replace it in case it did. As I had some important things on my cellphone, I told them I would go back the next day, so I could backup my things.
Next day I fully charged the iPhone, quit the nanoSIM and put it into my iPhone 4 (whose battery lasts for more than 4 days on stand-by) and then I went to school. That wast at 7AM. 9 hours later, I went out of school and went to the store. "At this time the phone must be death" I thought. I took it out of my pocket and I found that it battery was at 98%. Only 2% less than 9 hours before!!!
Although that, I decided to leave the phone and supplicate to the technician to check it as soon as possible.
The next day he called me and told me that he had restored the phone and in 12 hours id only consumed 4% of battery, so I went back to the store to pick it up.
I got to my house, put the SIM on the phone left the phone on the desk. I went back 4 hours after I put the SIM and the battery was at 15%! so I guessed the problem was happening when I put the SIM on it. Yesterday I put the SIM and left the iPhone without any usage and yes, eight hours later, it was dead. Then I fully charged it, quit the SIM and waited again. Nothing. Battery almost full even after 12 hours.
On monday I'm totally going to the store and ask them for a new iPhone. The bad new is that I would have to wait 2 weeks to receive the new one, but I don't care, I want it to be perfectly fine, it costs a lot of money as to be suffering with things like that.
If you can, check yours without the sim card, and check if the problem is still there. Regards.