APPLE iPhone 4S, ios 7.1 update, battery issues?

Last night my daughter installed the ios 7.1 update on her iPhone 4S. Prior to that, it worked just fine, or as normal as other iPhone 4S's batteries go. But this morning we noticed the battery was at 12%. When she put it on the charger before bed, it was sitting at 87%. It's a new charger cord & plug that has also worked just fine, in a wall outlet that works fine as well. Does the new ios 7.1 have some kind of battery draining issue for 4S? Any ideas out there?

Nothing At All. There Are Many Ways That Drains Battery Fast, Helps:
Low Brightness
On Reduce Motion
Get Away From Low Signals
Remove MultiTasks
Use Airplane Mode

Any new OS update on IOS, Android, Windows, Blackberry on an older model phone will drain the battery faster and OS runs slower simply cause the new OS was not made for the hardware (CPU and RAM) in the older model phone… That's just a fact of like… See IOS7 on a iphone 5s versus a 4s. Shoot, even the Iphone 4 original…

But 87% to 12% in 8 hours of sleep (idle) time… 87 to 67 is more believable… Either 1) she was awake at night explorer the new update on her phone and is lieing her but off to you… Or… 2) Sounds like a bad update, which is rare on Apple… Worse case scenario the update broke the phone, in which case you call Apple right now… Or… 3) do an itunes restoral. And if she drops 70% battery in idle mode in 8 hours again-call Apple… Or wait, 4) she really was truthful and really was sleeping at night, but she kept the phone on and she has a lot of background processes going on in her phone that made the CPU continuous cycle (CPU usage = battery usage on any computer device)… Maybe she was playing music to help her sleep or has A LOT of social network/email push notifications happening. Like Android, the more you make IOS do, the more battery it uses.

I would personally do #3 and maybe #1. Knowing Teens, aka "The Millennials" or Generation Y (WHY) lmao… It wouldn't pass my mind… Lmao

My iPhone 5 has been losing one percent every few minutes on standby unplugged since the update.

https://twitter.com/...6135383042

It is happening other phones.

I have an iphone 4s that updated to 7.1 also. For about 24 hours everything was working fine. Then suddenly my phone just went dead. It went from 76% to dead. Like black screen of death dead. It still connected to iTunes fine but would not do a hard restart. When plugged into the wall charger or my laptop it made the "I'm charging ding" repeatedly. It also felt really hot to the touch. I let it sit over night then tried a hard restart, which worked. When it turned on it had an 8% battery. I was checking email with a 76% battery before it went brick. It went to 8% sitting on the counter overnight in blackout mode.