Re: Battery Life - Tips and Mythbusting
Signal Strength
There isn’t a whole lot you can do about this, other than move to another location, but a weak signal causes the phone to amp up the gain (amplification to the radio) which plain and simple eats power. At home, I’ve got a strong cellular signal and strong WiFi, and can get a good 24 or more hours of light usage out of my OEM battery. At work, I have strong WiFi, but weak cellular. Even with WiFi in use for data, I’d get at best about 15 hours. Turn off WiFi, and rely on that weak cellular, and I might get 8. Life in a weak signal area sucks: complain to your carrier, buy an extra battery, or move.
1. Things you can do that have relatively low impact to phone functionality
Radio Usage
Turn radios off when you’re not using them
Radios use some power even when not actively being used. Read on for specifics
WiFi is better than 3G which is better than 4G
In general, that’s true. But, signal strength plays a big role. A very weak WiFi signal may, in fact, force the phone to use more power than a strong cellular signal.
If you have weak WiFi, but strong cellular coverage, consider turning WiFi off, and relying on cellular
Consider using VOIP if you’re in a weak cellular area but have strong WiFi
A program like GrooVe IP will let you make and receive calls over WiFi. You can turn on Airplane mode, turn WiFi back on, and get and make calls, receive emails, surf the web, etc. Drawback: no SMS or MMS, which rely on the cellular network. I believe there are apps that claim to allow texting over WiFi, or via email, but I haven’t tried any.
If you have a good WiFi connection, set “Keep Wi-Fi on during sleep” to Always
Go to Settings /Wi-Fi / Menu / Advanced and make sure this is set. If you have weak WiFi, you might want to set it to “Only when plugged in.”
Turn WiFi off when you don’t have a WiFi connection to use
If WiFi is on, and not connected, the S3 will scan pretty much continuously looking for a connection. This will eat battery.
Turn off Sprint’s Connection Optimizer
It’s a great idea: use the more efficient, faster WiFi connection when it’s available. The problem is that this has the phone searching for WiFi even when it doesn’t exist, which eats battery. And since most of the Wifi connections it does find are private, you can’t connect to them anyway.
If you’re not in an LTE area, turn off 4G LTE
There’s a little bit of controversy about this, but my non-scientific testing indicates better battery with LTE off. On the S3, there’s no simple way to turn LTE on and off. If your area doesn’t have LTE yet, you should probably turn it off and leave it off.
If you’re in an LTE area, you’ll need to decide between speed and battery life, or reboot a lot. To turn LTE off, go to Settings / (Wireless and network) More settings /Mobile networks / Network mode, and choose an option without LTE. (On Sprint, this says CDMA, please let me know what the options are on other carriers.) Your phone will reboot. To turn LTE on, do it again but choose the options with LTE.
Turn Bluetooth off when not in use
This doesn’t seem to eat as much battery as WiFi, but it will scan for connections periodically.
What about GPS?
This isn’t quite as clear cut as it used to be. From ICS forward, turning the GPS radio on in settings doesn’t mean the GPS radio is on all the time. The OS now controls this pretty effectively, and only turns the GPS radio on when an application is requesting location services. Controlling those applications is more important than turning the GPS radio itself off, but if you want absolutely maximum battery life turning GPS off, and preventing programs from using it for location services will help. USING the GPS, for navigation or location services, will use lots of battery. If you’re using your phone as a GPS in your car, invest in a car charger. More about location services later.
What about NFC?
The Android implementation of NFC is pretty smart. If the screen is off, the NFC radio is off. If the screen is on but locked, NFC is on but not actively polling for connections. But if you keep the screen on playing games, you might want to turn the NFC radio off.
Update (11/13/2013) If you use NFC, check this: Under Settings / Wireless & network / More settings, if NFC is switch on, tap NFC (not the on/off toggle), and turn Android Beam off. Android Beam, it appears, keeps the NFC radio on a much greater percentage of the time. I've not verified this, but it seems to be reasonable.
Turning these radios on and off all the time is a pain in the ****. Isn’t there a better way?
Since you asked, yes. If you have a Samsung phone, you can use TecTiles to easily switch various radios (and other settings) on and off when you get home, get to work, are in your car, etc. Alternately, use a profile manager that can turn various radios on and off depending on your location or other conditions. Here’s an example: I have a home profile that turns off Bluetooth and turns on WiFi (and more, but we’re just talking radios right now). When I leave the house, it switches to a default profile that turns BT and WiFi on, until I get in my car, where connecting to the car BT turns WiFi off. At work, WiFi gets turned back on, and BT off.
I use an app called Setting Profiles, which works well for the most part, but seems to be unsupported these days. The free version will do almost everything the pay version does. Another program is Llama, which many people seem to like but I’ve not used. Tasker is the King Kong of profile apps, and will control things nothing else will, but the user interface is awful, the program complex, and the learning curve steep.
Control background syncing
While having the radios on uses power, actually using the radios eats even more. Checking email, uploading pictures, sending texts, notifications from Facebook, location check-ins, and more, all have the potential to eat up battery.
It’s simple: the more often apps sync, the more battery they use. And there are dozens of apps that sync: email, calendars, contacts, dropbox, Weather widgets, Facebook, Twitter, Skype, Google Talk, and more. Worse (and this is something Google needs to fix), each app syncs completely independently of every other app. So you might have everything set to sync once an hour, but still have sync events 15 times an hour. If you’ve got email set to sync every 5 minutes, Facebook every 30 minutes, Twitter continuously, etc., you’re going to use a lot more battery than if email syncs once an hour, Facebook only when you open the app, and Twitter once an hour. Each app has its own settings, so go into each one and set the sync interval for the longest you can stand, or to manual / never for ones that don’t really matter very much. Check the settings in every app: some you might never have suspected of syncing at all may surprise you. And recheck once in a while. Facebook, in particular, seems to ignore what I’ve set and turn automatic syncing back on all by itself. Skype and GTlalk like to keep connections open and sync behind your back. Sign out of them when not in use.
(update 11/13/13) Control Google Account syncing
When you set up a google account, Android defaults to syncing almost everything associated with that account, email and calendar, which are important, Drive, Play Books and Play Music, which might not be, Internet, which isn't if you don't use Chrome on your computer, and Google Photos and Picasa Web Albums. These last two can use a lot of data, and a lot of battery. Go to Settings / Accounts / Google, choose your account(s), and uncheck thinks you don't need to sync all the time.
Turn off automatic updates in the Play Store
This is another kind of sync, and it’s one that can download huge amounts of data for some updates. Control them manually, and update when you have plenty of juice, and preferably when connected to WiFi.
Push email vs. regular sync intervals
This can be a tricky one if you need to check your email frequently. Let’s look at the simple situations first, though. If you don’t need to see your email frequently, set a long sync interval, like an hour or more. That will almost always use less power than push email.
But supposed you want to be notified about an email more or less as soon as it’s received? Is push better than a short sync interval? The answer really depends a lot on your email patterns. If you get lots of emails spread out fairly evenly, push can use a lot of battery. With push email, for each email received, the server notifies the phone there’s an email available; the phone’s email app connects to the server and pulls down the email. If it does this 200 times a day, getting only 1 email each time, that’s a lot of battery. Using a 15 minute interval polling interval and getting 10 messages at once is probably more efficient. But if you get 10 emails a day, waiting for the server to notify your phone will be much more efficient than polling every 15 minutes.
Control Location Services
By default, Android wants to keep track of where you are. You can control how it does this, and what it does with the data it collects. Depending on your settings, this can have a huge impact.
Go to Maps / menu / Settings / Location settings. Unless you have a real need for these services, uncheck “Report from this device,” “Enable location sharing,” Automatic Check-ins,” and “Check-in notifications.” Location reporting and Enable location history don’t seem to have as big an impact, but if you want maximum life turn those off, too.
Look at your apps, and figure out which ones have location dependent activities. Google’s “Field trip,” for example, is cool, but needs to update your location pretty regularly. Foursquare, Facebook status and check-in, Locale, and any similar app will drain your battery in a hurry. There are thousands of location-based apps in the Play Store, including games.
Screen Usage
Depending on how you use your phone, the screen may be the largest drain on your battery. The OLED screen is big and bright, and we pay for that in power drain every moment it’s on. (Note, you’ll read references in other places to our screen’s “backlight.” OLED screens don’t have backlights. But they still use more power the brighter they’re set.) There are only two things you can control relative to the screen: how much it’s on, and how bright it is. Playing games, surfing the internet or watching videos for 3+ hours a day is going to use a lot of battery. If this is your usage, be prepared to recharge more often, or buy an extended battery or spare batteries. Micro USB chargers and car chargers are cheap and easy to find.
Turn down the brightness
When I first got my S3 I left it on auto-brightness, but I’ve discovered that in most locations I can comfortably view the screen at lower settings than auto chooses. Just like turning radios on and off, though, constantly changing your brightness gets to be a pain. Use TecTags or a profile app (see the section on radio usage, above) to automatically set brightness appropriate to your location.
Turn the screen off
The GS3 will let you set the screen time-out from 15 seconds to 10 minutes. Set it to the shortest value that works for you. This is one place where Smart Stay really helps. You can set the time-out to a short value so you it doesn’t stay on when you set the phone down, and Smart Stay will keep it on while you’re actually looking at it. Profile apps can come in handy here, too. For example, I have my timeout set for 30 seconds normally, but have a profile set to a longer time period if I’m using my Kindle app or am in my car.
Other things
Turn off Haptic Feedback
The little vibration motor seems to use a fair bit of battery. I don’t think haptic feedback really accomplishes much anyway so I have it turned off. If you like it, don’t worry too much. Compared to the radios and the screen, this is pretty minor.
Turn of vibrating alerts
See haptic feedback, above. Personally, having these alerts is more important to me than the slight amount of battery they use up.
2. Things you can do that have a bigger impact on functionality
Turn on Power Saving in settings
This will throttle the CPU, making the phone run slower and use less battery. Some people report it helps, some say it doesn’t do much. Some complain it makes the phone perform very poorly. I think it depends a lot on how you use the device, so give it a try and see.
Turn all radios off except when you want to check something
You’ll find a lot of apps in the Play Store that purport to improve battery life. Some actually work, but generally at the trade-off of functionality. And you can do most of these things manually, but an app makes it easier. For the most part, they work in similar ways, by limiting the on-time and usage of the radios. If you turn off WiFi and Mobile data, and only turn them on a few times a day to check and see if you got any email, check your sports scores, or whatever, you’ll get much better battery life. I didn’t buy a smart phone to turn it into a dumb one, but if battery life is more important to you than connectivity this is a big one. You can automate this process with certain apps.
Juice Defender lets you schedule when the radios are turned on, so you can keep them off most of the time, saving battery, and turn them on briefly once an hour, for example, to let everything that’s been waiting to sync catch up. 2X Battery is a similar app. Snapdragon Battery Guru is similar, but claims to learn the best way to control syncing based on your usage patterns. There are dozens more. (But watch out for those that claim to improve battery life by stopping background processes. That’s almost never a good idea.)
These apps can make a big difference if you have weak signals and if you don’t care about being connected all the time. But when your wife / girlfriend / mother emails you that she’s headed to the hospital with chest pain, and you don’t get the email until 2 hours later because all your data was turned off, you may wish your priorities had been different. Yes, that’s an extreme example. I’m just making the point that there’s a trade-off between real-time access to data and battery life. Everyone has to make up their own mind how to balance that trade-off.
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