[Samsung Galaxy Nexus] littlewierdo:
Battery life issues:

Again, I dont have a Nexus but I do have alot of experience with Android.

Two quick points.

1. Battery life is mostly software learning nowadays. You cant make a judgement call in less than a few days. Depending on how this update works, it might wipe your battery stats which would make Android behave differently and report inaccurately. The rule of thumb is that Android takes 3-5 complete charges to completely 'learn' and report accurately. A complete charge means, use the phone til it dies, then charge the phone (once a week, the phone should be charged with the phone powered off for best results, the other 6 days the phone should be on). If you charge the phone starting from 50% battery life left, that is only a half charge so it will take longer for the phone to 'learn' (meaning if you charge the phone at 50% battery left every time you charge it, it will take 6-10 charges for the phone to accurately 'learn' or predict usage patterns and battery left).

This update may also cause 'spikes' in power usage that the phone hasnt yet seen. Battery reporting is also prediction based so this may cause inaccuracies initially.

The point here is, give it at least 5-7 days AFTER installing the update (or a factory reset/manual battery stat wipe) before making any assumptions on battery life. If you can do it, consider wiping the battery stats manually so that your phone can begin to rebuild the battery data based on whatever this new update is doing, rather than mixing the way the old firmware behaves with the way the new version does.

2. If you are having 'ANY' issues, try a factory reset. Try as they might, sometimes non-wipe updates create wonky issues. If I recall correctly, in ICS, its under Settings->Privacy. I know its a bit of a pain but you'll keep root (if you have it) and you can use Titanium Backup (requires root) to backup your installed apps. FYI, a factory reset also wipes the battery stats. After wiping the battery stats manually OR doing a factory reset, give it at least a few days before making a judgement call on battery life.

I highly recommend purchasing Battery Monitor Widget Pro by 3C (make sure you look for the one by 3C!!, there are are others with the same name) on the Play Store - absolutely the best battery monitor out there with tons of settings, graphs/charts, and data logging to determine exactly what is using the battery. Trust me, just look at the screen shots, its more data than even I know what to do with and I love statistics and data analysis (and has a 5 star rating, something very few Android apps have). FYI, he does another app called System Tuner Pro which is awesome as well. Just search for '3C' on the Play Store and they both should be near the top.

Battery Monitor Widget Pro

https://play.google.com/store/apps/...ult#?t=W251bGwsMSwxLDEsImNjYzcxLmJtdy5wcm8iXQ..

System Tuner Pro

https://play.google.com/store/apps/...r#?t=W251bGwsMSwxLDEwMiwiY2NjNzEucG13LnBybyJd

---------- Post added at 05:31 AM ---------- Previous post was at 04:54 AM ----------

One other quick thing (I promise), dont be fooled by the 'improved signal strength', I read an article that Google artificially boosted the signal strength with this 4.04 update that is based on a logarithmic scale now instead of a linear scale. Meaning that, instead of each 'bar' in the signal strength indicating a certain amount of db (lets say 'X' db so if 4 bars were highlighted it would mean db = x * 4 (because four bars are lit)). After this update, each bar means an increasing amount of db (for every bar lit means an exponential amount more) meaning that 1 bar might be X, 2 bars might be X * 5, 3 might be X * 8, 4 might be x * 10. I hope this makes sense.

http://en.wikipedia.org/wiki/File:Logarithmic_Scales.svg

The top left graph shows an example of a linear scale, each vertical axis in the graph equals a set amount (ie. 0,2,4,6,8,10), the top right graph shows an example of a logarithmic scale where each vertical axis equals an exponential amount (in this example, each vertical axis equals 10 times more than the amount of the previous vertical axis ie. 0.1,1,10,100,1000).