Join Date: Aug 2011
Carrier: EE UK (4G)
Thanked 1,819 Times in 1,121 Posts
In addition to Simes great pointers above, I would like to add the following.
There are basically 2 areas to focus your attentions to on battery life.
1. For when your screen is on
2. When your screen is off.
Obvious eh? But just think about this for just a second...
* The screen is THE biggest battery drainer there is. Full stop. Its one of the pitfalls of having such a good one!
* The most used state of your phone is when its on idle.
Therefore, if you can make inroads into improving the efficiency of your phone in one or ideally both of these states, then you will be enjoying your phone for much longer periods between charges.
Screen-on battery saving tips:
1. Turn off live wallpaper.
2. Use the auto-brightness setting for your display. (menu>settings>display>brightness>automatic brightness)
3. turn off dynamic screen mode. Use movie or standard (menu>settings>display>screen mode)
4. set your screen timeout to as short as possible without it becoming annoying. I set mine to 30 seconds.
5. menu>settings>display>touch key light duration. Set to 1.5 seconds. Believe it or not, these LEDs use a LOT of power. Some people say they do not, but they really DO. If you have BLN, send yourself a message so the LEDs stay on, and look at the battery usage graph a few hours later and see how it plummets.
Screen off battery saving tips
1. Scrutinize the applications you have installed. Think about what they actually do. Do they need to grab information periodically? If so, do you need the app in the first place? If not remove it. If you do, find out if you can define the period/frequency at which it grabs its data, and set it to as long a period as possible without spoiling the usefulness of the app itself.
2. Dont clutter you homescreens with scores of widgets. Only keep what you actually need. If you have a widget on there that you dont really use, remove it.
3. Almost everyone seems to have a weather widget. I use Fancy Widgets for this. I set this to update once per hour, but this can be turned off completely overnight. Many other weather widgets do not have this switch-off feature. It DOES make a difference!
4. Check your battery useage with betterbatterystats. Look for any Partial Wakelocks. Are there any processes that are taking a lot of CPU that perhaps shouldnt be? If so, identify the app and if you dont really want it, remove it.
5. Check your CPU states using CPU Spy. Overnight you should get around 97% deep sleep barring too much internet-based apps requiring data.
6. I dont bother switching data/wifi/gps off overnight. As long as you dont have too many of these wakelocks overnight, there wont be much of a hit battery wise
7. Dont turn your router off overnight!!!! You will use far more battery when your handset cannot find your wifi as it attempts to reconnect. Also, data battery drain is more than wifi battery drain, so therefore any overnight data downloads due to no wifi connection would make a big impact on both your data usage allowance, AND battery. If your insist on turning off your router, then I would advise you switch off wifi AND data on your handset.
8. Make sure you are on the latest Google Maps. Some older versions have a NetworkLocatorPassiveCollector wakelock bug.
9. Check your running services for any you dont need. Settings>applications>running services. Apps like NoLED will drain your battery, not only when its displaying an "LED" on the screen, but just by running in the background. If your rooted, then BLN will use battery, but not as much as NoLED (just to run). Remember, anything running on your hanset needs power, whether it is something you see running on your screen, of if it's running hidden in the background. So for this reason, be aware of applications such as JuiceDefender and similar. If your phone is already in an optimal state, then such apps will have a negative impact on your battery.
10. Before you leave your handset overnight, go into Task Manager and exit all running apps. Reason being, for example, you may have an internet session open that automatically updates, and this will take a big hit on your overnight drain.
Tips for rooted users
1. Use Voltage Control to tweak your CPU+GPU voltages. These settings will be almost unique to your particular handset in a way, so it can be very much a trail and error thing. Tweak as much as you can out of it without the dreaded screen freeze.
2. If you use BLN and are on the paid app, disable BLN overnight (for reasons stated in point 5 in the first section above. If your on the free app, limit the LEDs to stay on for a max of 1 or 2 hours.
3. Try different kernels. Find out which one suits you best. Siyah and NEAK are the best for me by a country mile. Both are extremely smooth. However, for me (and I stress me!) I find NEAK to be almost twice as good as Siyah with regard to overnight battery drain. I strive to get approx 0.5% battery drain per hour overnight. This is my yardstick. Overnight drain is the only way I can accurately see how my battery is coping, as this overnight state is pretty much a constant, unlike the randomness of battery drain during actual use. I used to get 0.5% per hour with older version of Siyah, but the more recent ones, although super smooth compared to the older versions, I get more like 0.8% - 1%.
People tend to dismiss the GS2 too quickly with regards to battery, writing it off as a resource hog. Its just not true. As long as your sensible you can keep your battery going for far longer than the doom and gloom merchants claim.