There has been a lot of talk about the battery life of the Apple iPhone 4S and the iPhone 5 following an update to iOS 7 beta. It seems that iOS 7 gives the battery life of the iPhone 4S hell, while that of the iPhone 5 comes out ok.
The Apple iPhone 5 manages to get away without any issues with battery life, while the iPhone 4S battery drains down fast. People talked about this last year when they updated and then started seeing their battery drain down. We took a look into it and you can install without seeing issues with battery drain.
This appears not be associated with hardware but more about with how you install the OS.
When we made tests they showed that the battery life of the Apple iPhone 5 got away with issues, while that of the iPhone 4S drained down in hours. This may be luck more than anything else and it seems to be how you install the update. You can install it without suffering from battery drain.
First you need to back up in iTunes in DFU mode. To do this you have to hold down the Sleep/Wake button along with the Home button. When you see the logo of Apple you then just hold down the Home button and you will get into recovery mode.
When you have gone ahead and installed iOS 6, you can then install iOS 7 and restore your data. You can also downgrade if you backed up in iTunes.
It seems that the problem with the battery drain of the iPhone 4S was huge. But if you do a clean installation first you can get away without any issues.