Battery Life

Battery Life
How To Get More Out Of Your Battery
by ceriko


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There is a lot of threads going on about battery life related problems, let's try and keep everything in one place.

First we'll see how to fix some Gingerbread specific problems (JVB & JVK), followed by a bunch of general recommendations to save power on all ROMs (Eclair, Froyo, Gingerbread) and there is a guide to calibrate the battery.

Android OS bug on Gingerbread ROMs

This is the most annoying Samsung/Android bug.

A good few people have been seeing battery drain on Gingerbread. It comes randomly and apparently once it starts the only way to stop it is to reboot... But it comes back after a while :eek:

You can identify this drain by checking the Battery Use in Settings : if Android OS is above 20%, often between 40 and 60% of the battery consumption while your phone has been idle most of the time, then that's it.

The good news is that there is a semi-fix :) found in XDA: 2 system apps are responsible for this leak, here's what to do using Titanium Backup :

Find Software Update & Samsung Account, select them one by one and "Clear Data". Now you need to freeze Software Update (if you have the Pro version of Titanium Backup) or to backup the app and delete it. Since you don't delete the backup, it's like a freeze. (But keep the backup in case you want it back for some obscure reason)

Or simply use the default app manager to clear the data and Root Explorer to backup/delete Software Update.

If the Android OS battery drain comes back after freezing/deleting the 2 apps above then I suggest you read about the app below. You can back it up and delete it as well and see if it improves:

wssyncmlnps.apk (info) - make a backup in case.

But the AOS BUG will probably keep coming because there is no proper fix to it (Google bug fixed on 2.3.4).

Please share your findings posting in this thread so everybody can know.

Tricks for all Android versions

Other important things to improve battery life:

- Set Wifi sleep policy to "never" in Settings > Wireless > Wifi > Menu key > Advanced > Wifi sleep policy.
- Set Settings > Display > Animations to "NO or SOME animations" (thanks to Phazeman for that), you will still have the overglow effect and the CRT screen-off animations is you select "some" :p (on ICS this setting was moved to Developer options - Window Animation Scale)

Now a little bit of magic:

Toggle the airplane mode on/off 3 times in a row, that will reduce your Cell Standby battery usage (thanks to Phazeman for that).

It should only be necessary to do it once after flashing but if you think Cell Standby uses too much power at some stage you could toggle again the airplane mode :)

Usual, basic recommendations :

- The best advice ever is to always flash with 100% battery :cool:
- Avoid having too many widgets,
- Avoid using live wallpapers,
- Avoid using energy saving apps (they actually run non-stop in the background, hence they use battery),
- Set your screen time-out to an acceptable low value, like 30 seconds,
- Brightness: use a low value (between min and 25%) or tick auto-brightness,
- Try different modems (as they are responsible for networks and networks use a lot of power)
- Buy a 10% higher capacity battery (1650mAh) made by Samsung for SGS devices (fits perfectly of course :D)
- Calibrate your battery.

Battery Calibration

(not needed if you flashed with 100% battery and let it deplete/recharge fully 2 or 3 times)

Sometimes the battery isn't being used to its full extent, or it shows wrong values. This is due to some wrong data stored in a file called batterystats.bin stored in /data/system. The steps below will show you how to stretch the battery use and delete the file in CWM (ClockWorkMod) in order to start with a full battery and fresh stats.

- Charge your battery full, bump charge to get the highest level possible ; note that it's not a big deal if it shows 97% when you unplug after bump-charging, more info in this article,
- Drain your battery to 0% until it shuts down by itself (without plugging the charger or connecting the phone to a pc),
- Wait 2 minutes and reboot the phone to ensure the battery is completely flat (it might reboot fully, half way, not at all, don't worry) until it dies again,
- Remove the battery and wait 2 minutes,
- Replace the battery and plug the charger without switching the phone on until it shows 100%,
- When phone shows 100%, boot in recovery (volume up + home + power) and go to > Advanced > Wipe Battery Stats > Confirm (move up/down using the volume keys),
- Reboot the phone and unplug the charger when the "battery full notification" comes (wait for the notification before you unplug the charger!!!!!),
- Now use your phone until the battery is flat again and charge full (no need to have it turned off, unless you want it to charge faster). Repeat 2 or 3 times and your battery will be calibrated,
- Only wipe battery stats once, run a few cycles of full charge / discharge and after that just use your phone as normal (i.e. no need to deplete / charge fully anymore).

Some explanations

The battery calibration tutorial I offer has been elaborated after a lot of reading. By draining the battery flat (completely flat) your Kernel somehow learns from that and charging full while off will teach your phone the full battery range available to your phone once you turn it on.

For example for some people the battery indicates 1% left and they can still play 1hr with it before it shuts-down by itself, that's because the phone didn't know the full range of the battery (I don't know why though) :)

So if they recharged their phone as soon as they reached 10 - 5% then they never used the full potential of their battery. This is where the battery calibration does its work, it will not purely increase the battery lifetime but show accurate percentage left. And it will become more accurate after a few cycles.

Instead of doing this calibration you could also keep charging your phone full and empty the battery fully each time and that would also calibrate your battery after time.

Anyway I repeat that the best thing to do is to Odin-flash with 100% battery and let the phone discharge fully at least once, then let it charge full. I reckon this is enough and painfree.

* People reading this should be aware that leaving the phone completely flat for a while can simply kill the battery (Li-ion batteries can't go below 3.5V or they stop functioning). I reckon a phone left completely discharged for 1 week **could** destroy the battery for good. But I also think that very few of us would live without their phone for too long :D
Jul 5, 2014
T!v@K, comnam90 and Robbie Hood like this.