Android Battery Life

[Salty Wagyu]

Location services (especially GPS radio) are only used if an app. needs it. Otherwise, it really won't consume much battery.

That's true, but Google Now uses it a lot in 4.1+

[Richteralan]

Thanks, I'm going to keep that in mind if my I find my N4's battery life to not be acceptable. Any quantitative information on how much difference running a custom UV Kernel like that will make?

The only quantifiable thing is the amount of voltage you decreased from the default one.

And you have to experiment with the battery life from there.

Not everything revolves around numbers.

[Growled Member]

Such sad-face to people recommending apps like Advanced Task Killer and Juice Defender. The folks at XDA have said these are useless since 2.2 and in some cases even have a negative impact.

I don't consider them the absolute last authority on Android. I know what works on my phone better than they.

[patseguin Global Moderator]

Specifically, I am using my new Nexus 10 alot. I can't go half a day without having to recharge it. My iPad on the other hand can go several days. SO my main things to think about are lowering the screen brightness and disabling Bluetooth? My nexus 7 is about the same, about half a day's usage and I have to recharge it. I am using the default screen brightness on both devices and both have bluetooth turned on. Are those my main factors do you think? I haven't really done any serious gaming other than Badur's Gate just a little bit.

[Detection]

Such sad-face to people recommending apps like Advanced Task Killer and Juice Defender. The folks at XDA have said these are useless since 2.2 and in some cases even have a negative impact.

I disagree completely, I think Androids memory management sucks, at least up to ICS, JellyBean seems better

Many times I would watch as my ram was sucked to near nothing and using a task killer sorted it

Yes it could be rogue apps but even still, if you don't have a way to manually stop them and Android does nothing to help, you end up having to reboot

JellyBean I haven't needed to use it very much and just leave the widget on the homescreen to show how much ram is available, plus the recent apps button now hsa a "stop all" feature added in the rom I use and that works fine

[DomZ]

Having to disable features that contributed to people choosing android and reducing screen brightness to prolong battery life is crazy. I'm hoping that manufacturers start investing in battery r&d rather than trying to up the processing specs all the time.

Having recently bought a Nexus 4 (mainly for development purposes but it is now my main phone) the biggest let down with Android has been it's battery life. Having previously used iPhones since the 3G days, and a WP 7.5 for a few months I'm shocked by how many people simply suggest turning the screen brightness right down, turning off wifi when you are not home ,etc.

This is crazy! I don't want to have to constantly baby sit my phone so it lasts a full day charge. With the iPhone I just left everything on and I had plenty of battery left at the end of the night.

Now that my slight rant is over I've turned off live wallpapers and tweaked a few of the advanced settings in the wireless settings, like turned off NFC etc and removed any apps that were running in the background that I weren't really using.The battery is lasting a day now but the hit and miss nature of it in the past means I am always conscious of it..

[patseguin Global Moderator]

Yeah I tend top agree Dom. A user shouldn't have to babysit their device to save battery. I did turn down screen brightness by 25% and turned off Bluetooth. I could probably disable NFC too. Does NFC suck batter just having it enabled?

[Detection]

Having recently bought a Nexus 4 (mainly for development purposes but it is now my main phone) the biggest let down with Android has been it's battery life. Having previously used iPhones since the 3G days, and a WP 7.5 for a few months I'm shocked by how many people simply suggest turning the screen brightness right down, turning off wifi when you are not home ,etc.

This is crazy! I don't want to have to constantly baby sit my phone so it lasts a full day charge. With the iPhone I just left everything on and I had plenty of battery left at the end of the night.

Now that my slight rant is over I've turned off live wallpapers and tweaked a few of the advanced settings in the wireless settings, like turned off NFC etc and removed any apps that were running in the background that I weren't really using.The battery is lasting a day now but the hit and miss nature of it in the past means I am always conscious of it..

I know when I bought my WP7.5, my battery life was horrendous, I remember a full charge > playing a game for 30mins>1 hour and getting the low battery alarm appearing, I almost took it back

But after a few searches on XDA etc, I read people saying after a couple of weeks their battery seemed to suddenly hold a much longer charge,

2 weeks later and exactly the same, it must take quite a few cycles for the battery to reach maximum capacity

But we do not have the technology for decent batteries yet, so the 2 main drains are screen brightness and wifi, until someone invents a nuclear fuel cell, we have to turn stuff off on these power hungry devices despite what we expect and demand from the manufacturers

Put one of these smartphone batteries into an old black&white / no screened mobile phone and that thing will probably last a month :)

[patseguin Global Moderator]

I lowered the display brightness to 50% on al my devices and it's amazing how good they still look. Battery life seems to be moderately better. Still though, if I spend a night of web browsing, emailing, and gaming, my battery is gone. The same activity on my iPad barely puts a dent in the battery and I can usually go a week before recharging.

[dancedar]

Pretty sure that like Apple's laptops, it's tablets have larger batteries. I remember seeing a MBP stipped down and seeing 5 if not 6 cells. My laptop has two.

Open an iPad and it's all battery inside, perhaps that's why.

[patseguin Global Moderator]

I only ask because you've been posting here a lot lately about your new toys. It's possible you are just using these devices more than you normally would because of the excitement of a new toy and trying to learn more about them.

You might be onto something lol.

[dnast]

You might be onto something lol.

Haha maybe. But after reading some of the above comments I just looked up the battery capacity of the 3rd-gen iPad and it's an impressive 11,666 mAh compared to the Nexus 10's 9,000 mAh. That means the iPad has almost 30% more capacity, which is[/] pretty significant.

[patseguin Global Moderator]

I went back to using my iPhone for a few days and it's highly noticeable how much more battery life I get. My Nexus 4 barely through a day before dying.

[AJerman]

I disagree completely, I think Androids memory management sucks, at least up to ICS, JellyBean seems better

Many times I would watch as my ram was sucked to near nothing and using a task killer sorted it

Yes it could be rogue apps but even still, if you don't have a way to manually stop them and Android does nothing to help, you end up having to reboot

JellyBean I haven't needed to use it very much and just leave the widget on the homescreen to show how much ram is available, plus the recent apps button now hsa a "stop all" feature added in the rom I use and that works fine

See, this is the thing. Your RAM SHOULD be used, otherwise it's wasted. Just because your RAM is in use doesn't mean you need more. It means the system is keeping recent apps in memory in case you switch back to them. Once you need that memory, it will close something older that it had open and free it up. This is why it has been repeated again and again that task killers are useless, and it's 100% correct.

That said, Juice Defender is not a task manager and does offer some potential benefits. It allows you to turn on and off features of your phone to save battery. A well tweaked Juice Defender config theoretically could save you some extra battery.

You might be onto something lol.

This is a very definite effect when getting a new phone. Most people will deny this, but I've seen it be true 90% of the time. When you get a new phone, you play with it more. You turn it on to show people, you turn it on to check something, you download all kinds of new apps, etc. This adds up and reduces battery life quite a bit in the first few days of owning a device. There's really no such thing as battery calibration with lithium based batteries, so don't worry about any kind of battery conditioning or completely charging and completely discharging or anything like that. Constantly turning it on and off will make it turn on and off stuff like wifi constantly and keep it out of deep sleep for longer, which will affect battery.

I went back to using my iPhone for a few days and it's highly noticeable how much more battery life I get. My Nexus 4 barely through a day before dying.

See, maybe we're seeing this different, but how long exactly do you need your phone to last? I'm not sure how the battery life is on the N4 in general, but with my One X I get 24 hours pretty easily, but if I were to play a bunch of games or use it heavily, it would be less. I have a charger at work and at home, most of the time I'm no more than a few hours from a charger, so I don't really see the huge deal about battery life as long as you can last around a day.

[Detection]

See, this is the thing. Your RAM SHOULD be used, otherwise it's wasted. Just because your RAM is in use doesn't mean you need more. It means the system is keeping recent apps in memory in case you switch back to them. Once you need that memory, it will close something older that it had open and free it up. This is why it has been repeated again and again that task killers are useless, and it's 100% correct.

That said, Juice Defender is not a task manager and does offer some potential benefits. It allows you to turn on and off features of your phone to save battery. A well tweaked Juice Defender config theoretically could save you some extra battery.

I agree to a point, RAM is there to be used, but when your device becomes sluggish / freezing and RAM use is 99%, there is a problem with memory management

Personally I see absolutely no need to have any 3rd party apps running in the background, for example, why do I need Angry Birds running in the background when I boot up and have not even opened that app for a month?

Using an app killer and then launching an app that is not running takes exactly the same length of time as opening an app that is running in the background

Can you imagine if Windows started opening PS or IE or Messenger whenever it liked, and your RAM use was constantly at 99%.... everyone would be scanning for malware

Android says it closes apps as more memory is needed, it would be quicker if that memory was free to begin with

[typu]

my next phone will be primarily be a decision of battery life and screen size.

i want a phone that is 4.3 inch (4.5 max!)

i want a phone with a battery lasting 24 hours without taking care of what i turn off/on

i dont care if its an iphone or android. my using pattern allows both of them equally well. it can even be the next RIM phone (preferably not a windows phone, lacking in too many things)

so ill see whats coming next. my wallet is ready, but i dont see the perfect phone yet.

[AJerman]

I agree to a point, RAM is there to be used, but when your device becomes sluggish / freezing and RAM use is 99%, there is a problem with memory management

Personally I see absolutely no need to have any 3rd party apps running in the background, for example, why do I need Angry Birds running in the background when I boot up and have not even opened that app for a month?

Using an app killer and then launching an app that is not running takes exactly the same length of time as opening an app that is running in the background

Can you imagine if Windows started opening PS or IE or Messenger whenever it liked, and your RAM use was constantly at 99%.... everyone would be scanning for malware

Android says it closes apps as more memory is needed, it would be quicker if that memory was free to begin with

When you use an app killer and kill that service that is running, it just starts the service right back up, thus wasting cpu cycles and battery. The solution is to not use apps that force a service to run for no reason. I don't like that so many apps do that either, but that's exactly where a task killer wastes your battery.

As for Windows, Windows DOES precache your RAM. Look at your free RAM on your computer right now. I have 109 MB free of 3980 right now because It's precaching things I may use frequently to make it faster. A lot of apps like messenger DO preload a service in the background to launch faster.

Android will run faster and smoother if left alone. Task managers should NOT be used.

[Detection]

When you use an app killer and kill that service that is running, it just starts the service right back up, thus wasting cpu cycles and battery. The solution is to not use apps that force a service to run for no reason. I don't like that so many apps do that either, but that's exactly where a task killer wastes your battery.

As for Windows, Windows DOES precache your RAM. Look at your free RAM on your computer right now. I have 109 MB free of 3980 right now because It's precaching things I may use frequently to make it faster. A lot of apps like messenger DO preload a service in the background to launch faster.

Android will run faster and smoother if left alone. Task managers should NOT be used.

Something is wrong with your system if you only have 109MB free, unless you have some huge programs running

And theres a difference between services and applications, yes some services start with windows, but applications, no, unless specifically told to

[bjoswald]

Other than disabling some of the usual suspects (syncing, WiFI/GPS, etc), another app that may help is Autostarts. If you can't already tell, it allows you to "pause" programs from booting up with Android, which will save battery. Of course it will probably require root access (and common sense), but the savings will be worth it if you have a ton of apps.

I use to be a big advocate of Juice Defender, but these days I don't need it. I am very mindful of what I download and I run a custom ROM/kernel that are updated frequently. I like my phone neat, clean, minimal and only use apps that enhance the phone's current functionality (unless a new feature is too good to pass up). Although my phone is 2 years old, it's very quick and has never failed me.

Also, for those of you who root, I suggest v6 Supercharger script by zeppelinrox @ XDA. I have used it for ages and it's amazing.

[AJerman]

Something is wrong with your system if you only have 109MB free, unless you have some huge programs running

And theres a difference between services and applications, yes some services start with windows, but applications, no, unless specifically told to

Haha, my computer is running just fine. It's perfectly normal. Granted I do have a couple of large apps in memory (Lotus Notes, ugh), but aside from that it's just fine. That's how it's supposed to run just the same as every other modern OS. As a friend of mine said, sometimes people just shouldn't see numbers because a lot of times they don't understand them. A small amount of free memory tells me my machine is efficiently using my RAM and not wasting it. As you can see with the "Available" number, there is a plentiful amount of RAM available to be cleared if something needs it. And the number of cpu cycles it takes to knock something old out of cache is nearly nothing, so no, I don't think it would be noticeably faster if the memory wasn't in use before.

Some services start with Windows just like the services that start at boot on Android. The services that task killers kill, and the services that start themselves right back up after being killed, wasting cpu cycles and battery. If you use a task killer and selectively went through and excluded every service so that you wouldn't have wasteful recycling of those services whenever you killed tasks, it wouldn't be as bad, but it still wouldn't be necessary. Android and Windows are not the same thing. Android, and all other mobile platforms, keep applications in memory after you close them because the UI is nearly always a single window UI. You can't multitask and leave multiple applications open like you can on a PC. It's the equivalent of minimizing an app on Windows, however, mobile apps are specifically built to save their state if necessary and be ready to be killed whenever memory is needed.

[Detection]

Haha, my computer is running just fine. It's perfectly normal. Granted I do have a couple of large apps in memory (Lotus Notes, ugh), but aside from that it's just fine. That's how it's supposed to run just the same as every other modern OS. As a friend of mine said, sometimes people just shouldn't see numbers because a lot of times they don't understand them. A small amount of free memory tells me my machine is efficiently using my RAM and not wasting it. As you can see with the "Available" number, there is a plentiful amount of RAM available to be cleared if something needs it. And the number of cpu cycles it takes to knock something old out of cache is nearly nothing, so no, I don't think it would be noticeably faster if the memory wasn't in use before.

Some services start with Windows just like the services that start at boot on Android. The services that task killers kill, and the services that start themselves right back up after being killed, wasting cpu cycles and battery. If you use a task killer and selectively went through and excluded every service so that you wouldn't have wasteful recycling of those services whenever you killed tasks, it wouldn't be as bad, but it still wouldn't be necessary. Android and Windows are not the same thing. Android, and all other mobile platforms, keep applications in memory after you close them because the UI is nearly always a single window UI. You can't multitask and leave multiple applications open like you can on a PC. It's the equivalent of minimizing an app on Windows, however, mobile apps are specifically built to save their state if necessary and be ready to be killed whenever memory is needed.

Well I've been running and repairing windows machines for years and years and the only time I see 99% RAM use is either when they have a malware infection or a shed load of high RAM use programs/games open

What is using all of your RAM? Look in processes and click the RAM column to move highest to top

[Joshie]

The important thing to remember is that anyone who recommends installing an application to improve battery life by managing memory/CPU is wrong >95% of the time. There's little to no evidence that third party battery savers make any real impact, and many of them are so detrimental to user experience that any increase in battery life at all will be at the expense of your enjoyment of the device.

Not to mention the risk of the Windows Effect: whatever crap is caused by third party tools is blamed on the OS instead.

Like security, your best shot at keeping your battery life at its best is getting to know your device and developing good habits.

My own personal Android tip: for the love of all things holy, disable automatic brightness in favor of a notification bar control, be it a toggle, slider, or the status bar swipe feature of CM. If nothing else, put a widget somewhere. Why automatic brightness is on by default for practically every Android device is beyond me--it isn't even an enjoyable feature if it worked.

[Detection]

The important thing to remember is that anyone who recommends installing an application to improve battery life by managing memory/CPU is wrong >95% of the time. There's little to no evidence that third party battery savers make any real impact, and many of them are so detrimental to user experience that any increase in battery life at all will be at the expense of your enjoyment of the device.

Not to mention the risk of the Windows Effect: whatever crap is caused by third party tools is blamed on the OS instead.

Like security, your best shot at keeping your battery life at its best is getting to know your device and developing good habits.

Yea I don't think task killers help with battery, just with Androids poor memory management (Prior to JellyBean)

And I'm not ruling out badly coded apps being the problem a lot of the time too

Same with Firefox, poor browser gets a load of grief because of buggy addons

[dnast]

^ Yeah, I've had to use task killers in the past when I've had a phone/ROM that would randomly slow down to a crawl at times. I'd do the task-killing manually, though. I wouldn't recommend it for saving power.

Like you mentioned earlier, I've also seen a few games (quite a while ago) that weren't running as services, but would show up in my "Running Apps" list soon after a reboot. I never figured out why that was happening so I just uninstalled them.