[Milestone XT720 General] sohrab.naushad:
Hey guys,

So after many months with the XT720 and alot of flashing and trying to get the most out of my battery, i've come up with a few conclusions about battery life in general and how to extend it. I thought I'd share here. This is mostly aimed at people who are new to android and have not experimented like some of the more advanced users we have on this forum. Hope you find this helpful and please feel free to make additions.

General Battery Info

The XT720 was my first android phone, and I came from a long line of typical nokia phones whose batteries would last for ages. I had no idea the kind of power an android device would use. When I started out using it, i was surprised at how quickly the battery would die. You'd think with advancing software we'd have better batteries but sadly batteries are lagging behind in technology. Generally speaking you can expect the following battery life from your XT720.

Heavy use: 10-14 hours

Moderate use: 16-20 hours

Light use: 1 day - 1 day 12 hrs.

Note: New batteries improve with each charge cycle. It is recommended to go through a few complete charge cycles when you buy a new phone. After that, complete discharges are not recommended and its smart to start charging your phone when it hits the 20-25% mark.

How to improve battery life

1: Battery Calibration

If you've ever flashed a new ROM, you must have noticed a sharp decline in battery performance. This is partly due to old battery statistics left behind from your old ROM. Android is a smart OS and collects information over time. The more you use it, the more accurate it gets. In the same way it collects information from your battery usage and reports your battery percentages according to that. When you flash a new ROM, sometimes android thinks that your battery is 100% when its really lower than that and that causes relative reduced battery performance. To deal with that it is recommended that you use a nifty free app called Battery Calibration from the android market. What this does it removes the old battery stats and allows your new ROM to create its own battery stats. Charge your battery to full, use the battery calibration. Drain once till phone turns off by itself and charge to full again. You will notice a sharp increase in battery life.

2. Battery Managment

We all know that android has its own battery management built in but it usually doesnt give complete information about the phone. For that you need to dive deeper into the settings. Usually if you experience battery drain its because of a rogue app and believe it or not some common apps you wont think off drain unnecessary battery. To see your complete Battery Stats input this code into the dialer.

*#*#4636#*#*

This will take you to a bunch of options. What you're interested in is Battery History. When you tap that it will show you two drop down menu's.

1) Other Usage

2) Since last unplugged

Other usage shows you how long your phone has been running and how long it has been asleep. Also shows you how long your wifi has been on and running and how long your screen has been on. It is important to see how long your phone has been running. For example if your phone has an uptime of 20 hours and its been running 5 hours out of that. Your run time is 25%. Which is very good. Sometimes an app can run even when your phone screen is off. This will represent a longer run time even when you have your phone lying on a desk or something. See this setting and correlate with the amount you have used your phone. Does it seem normal? If no then use the first drop down menu and select

Partial Wake:

Partial wake is basically, any app which takes your phone out of sleep mode to use the CPU even when youre screen is off. These are apps which need to sync or use the phone resources. In this you will see a list of apps and how much they have caused a partial wake lock. See anything unsual? For me one app that caused unsual drainage was latitute. Yes, i had simply signed into it and i didnt know it was updating my location every 5 minutes. Extreme battery drain for me even when my phone was idle. See which app was draining your battery and either tweak the settings or remove altogether.

GPS, Sensors, CPU:

You can also see these in the first drop down menu. Certain apps like screeble use the sensors alot, and hence cause drain. Obviously games, camera, will stress the CPU. See if anything is causing drain in that and adjust accordingly.

Miscellaneous Information

After you have dealt with rogue apps that you don't use that drain youre battery your battery life will depend on how you use your phone. But hopefull these tips will help you with increasing your battery life. I do have some more information on different settings and supposed battery saving applications.

Autosync: When you enable auto sync, you allow google and other accounts to sync on a regular basis. This is important for people who need to use push email etc. It does not drain battery IF you tweak what you need synced. In google for example you can have your contacts, calendar, google+, google reader, gmail all to sync by default. If you just need email, please untick the rest. This will help you save battery life. Increase your update times for facebook and google+ if you dont recieve many updates all the time or turn them off altogether. If you have many services syncing at the same time you will get battery drain.

Wifi Sleep Policy: This is sort of a hidden menu. If you go into wireless & networks >> Wifi settings >> settings key >> advanced >> wifi sleep policy. This has three settings. Never close down wifi, never close when charging, or close with screen off. If you choose never your wifi will always be on, which will in turn crunch the **** out of your battery. If you use it off with screen off, remember it takes about 5 minutes to turn the wifi off. I personally use the never with plugged in. Its an intermediate. So when im plugged in wifi always stays on and when im not it follows the screen off protocol.

Wifi Vs Mobile Data: Having mobile data on all the time, does not drain battery. The only time the battery gets drained is when the data connection is active i.e you have many apps on autosync youll see your battery going down. If you arent doing anything and your phone is connected to Edge or 3G your battery will drain regularly. 2G networks drain less than 3G keep that in mind. If you are actively using your connection, wifi will take less battery because speeds are faster and you will be using it for a little time. Also your signal strength has alot of effect on battery. If you have crappy 3G signals your radio will actively be searching for a connection the same goes for wifi. That is important to keep in mind.

Control Background data: By selecting this option you can allow or disallow apps to connect to data without any permission. Some apps require this like the android market. If you uncheck this apps wont be able to sync automatically in the background.

Milestone Overclocking: This is fairly obvious. The higher you overclock with higher vsel the more battery drain you will have. Some use set cpu with profiles but I found that if i set the setcpu too low while idle It takes time for the cpu to charge up when i recieve a call or turn the screen on. Ringtones lag etc etc. I let android do my CPU management and its fine. and comfortable setting would be 850 MHZ, 56 vsel but you can change according to your phone usage.

Juice Defender/ Screebl / Task killers:

In my personal experience with juice defender ultimate I found that with the above precautions juice defender didnt make much of a difference and actually used more battery. First off theres an extra process going on in the back. Second activating and deactivating the connection everytime the screen goes off uses more juice because your radio has to search for the signal hundreds of times as compared to not having it in the first place. Screebl is good if you dont want your screen to annoyingly turn off while youre doing something but it surely doesnt save battery life. Task killers are a no no for android. They kill tasks which start up anyways, its better to use autokiller memory optimizer which tweaks androids internal memory settings and allows for more free ram without killing processes without reason.

System Apps:

Some system apps run uselessly in the background specially with stock ROM's this is called bloatware. Remove all unused system apps with titanium backup to stop them from running in the background for no reason at all.

A final word

Finally after all this tweaking, just use your phone as normal. Dont worry about the battery all the time checking how much its drained, itll mess your head up and make you enjoy your phone less. Battery temperature also changes battery life. Keep your phone out of the sun or in hot places.