Alright. I have a droid razr. This update has royally screwed me over. My phone can't live more than like 5-6 hours now. I used to have problems with gingerbread but they released an update for gingerbread a while back that doubled my battery life to about 16-20 hours of regular use. Now that I got the ICS update it's back down to like 5. I don't understand why. I use a battery saving app called juice defender. My phone also charges REALLY slow, and gets REALLY hot. I was using a 5 amp charger to charge it and it soaked up ALL 5 amps in a few hours and still wasn't fully charged. I just don't understand how it can be this much worse. It's making my life much more difficult when my phone can't even stay charged when all it does is sit in my pocket...
Take a look at Settings > Battery
It will look something like this:
From here you can see which apps are using the most of your battery. Touching each will let you know the amount of time the screen is on or how long your voice calls have been along with other information.
You can see the app Sleepy Time on mine and that it used 4% of my battery power so far. That is because I had it running for about 4 hours last night when I went to bed. Anything that is using a lot of your battery will show up here. This area can help you figure out what is killing the battery.
If you touch the top part with the graph it will give you a better view of it:
From here you can see the quality of your cell reception (green is good, yellow is ok and red it bad), GPS, Wifi and screen usage. You can also see the times you have been on the charger. This should be able to help you see when during the day your battery started to be used more.
I have not had a lot of experience with juice defender, but I do remember it giving some people grief on the Galaxy Nexus with ICS. You may want to poke around in that forum and see what the problems were.
You also have to remember that things run a bit differently with ICS overall. You have the recently used app list and some of those may not shut down properly so it is always a good idea to swipe them off the screen when you are done. Long press on the home key brings up this list.
Another place to look is in Settings > Data Usage.
This may give you an idea of any apps that are using a large amount of data. Large amounts of data being used may also lead to larger uses of the battery.
In the end, overall battery consumption is caused by the normal things most of the time. The screen, cell network and reception (bad reception uses more battery), leaving apps running (always use the back button to exit apps), etc.
There are also things that will help you conserve battery life like using wifi when available, setting the screen brightness lower (around 30 or 40 is good), turning off data when not in use or in a bad signal area, switching to 3G only when there is no 4G in your area, etc.
Hope that helps.
..congrats
