Friday, 29 April 2011

Samsung Galaxy S II (2): Battery Life - Moderate Usage

Note: This post is about "Moderate" usage and battery life. I've done a similar test for battery life under "Heavy Usage" which you can find here: Heavy Usage Battery Life 
Well this is a rather pleasant surprise! I've had the Galaxy S II for a little over a week now so I feel it is far enough into its charge cycle to comment on the battery life...

This first picture is the phone's battery on around 60% charge on what for me is "moderate" usage after 15 hours. There are periods of inactivity, but over the course of the 15 hours I played a few quick games, browsed a lot over HSDPA, had constant gmail twitter + facebook push updates, watched a couple of YouTube videos and listened to a small amount of music. A couple of quick phone calls in there, too. I didn't have wifi turned on here because my HSDPA connection is around 4Mbps.

I think this probably represents fairly typical usage of a phone. Heavy usage such as transferring large amounts of data over wifi / uploading a video to YouTube obviously drains battery life a lot faster than normal. 

This second picture shows the phone on the same charge as the first one, but you can see the battery drain is somewhat faster as I am watching more YouTube videos, making calls over skype and in general using a lot more data content (again no wifi). You can see this as the second, slightly steeper, downwards slope that goes in to the yellow.

The third "section" of the battery is the red section, near the end of the battery's life on this charge. I left the phone "awake" for a good chunk of that time, with several applications running idly in the background. This drains the battery somewhat faster than closing background applications but the drain on the battery is still looking pretty good. In case anyone is still asking if the Galaxy S II's battery can outlast a day, I thought I should include one final photograph, now with a "critically low" battery, having just outlasted the two day mark...!

[watch this space for updates]

I thought that battery life might be a chink in the armour of this mighty phone. I expected the the large display and the 2 x 1.2Ghz processors would eat the battery in a few hours but ... it turns out that the Galaxy S II can easily keep up with, if not outstrip, any competition in terms of battery life, whilst providing one of the smoothest and fastest user experiences I have ever encountered.

I look forward to the time when phone batteries will outlast a week. Battery-life has taken a huge hit since the start of the smartphone, but I do see the Galaxy S 2 as a step in the right direction. Samsung have not filled up a box full of magic and squashed it down into such a small package at the expense of anything: I really thought that battery life would be compromised but it just continues to amaze me. Wow!


  1. real nice to see that it has a nice battery life

  2. Hi,

    When you mention it's charge cycle what would that be like? I have a tendency to leave my phone synced to my laptop during office hours which charges it. Would you recommend a full discharge between charges?

  3. Hi @Jonathan! by "charge cycle" I mean totally depleting the battery and charging it back up to 100%. I think good practice, certainly with a new device, is to fully charge it and run it down to 0 a few times to get the most out of your battery. This optimizes the battery's capacity and allows you to use it to it's full potential. I think that's why the first thing most usermanuals will tell you to do is charge your phone to 100% before turning it on. I'm not a battery expert so I'm not sure! I think leaving it on charge all the time is less bad for a lithium-ion battery than one of the old nickel ones!

  4. Hi, thanks for the tests so far.

    Could you test the App JuiceDefender on the Galaxy S2 and post the results.

    Thanks in advance

  5. Hi Dom .TnX For Your Great Blog.Sorry For My Bad English
    i have some Question
    1. In this test brightness was on which level?
    2. was the motion sensors on in whole 2 days?
    3. If i just use this phone for 5 min call,50 SmS,30 min Game,and 30 min playing with setting (wifi off, Gps off, blu off,sensors off,2G network,10% brightness)per day,can phone lives for 3 Days?


  6. Can you tell me what is the name of the application you use to log the battery activity?

  7. 1) for this test the brightness was on "Automatic".
    2) The motion sensors were not turned off.
    3) I think you might be able to get 3 days out of it: yes!

    To get battery usage data from the phone there is an application/facility pre-installed. If you go into the main phone "settings", scroll down to the bottom to the "About Phone" page then there should be an option named "Battery Usage". If you press on that you should be able to see the battery statistics, and if you press on the graph at the top it will give you a larger version of it: as I've been using in these posts!

  8. Hi mate, Thanks for the post. I've owned the phone for a week now too and i've had much less success than you. I did manage to get 21 hours off of one charge but now it is much more like 8 or 9 hours. I would like to know much more about the settings you have used to get such results.

    Are you still getting such decent life or does it vary charge to charge?

    1) do you kill any Apps through the task manager?

    2) what mail app are you using?

    3) how often have you set facebook and twitter to poll?

    4) what widgets do you have on your Homescreens

    5) do you have any live wallpaper set?

    6) finally, under your battery usage graph do you have a large percentage of consumption from android os (and the other android entry) and wifi sharing? Lots of people including myself are getting a lot of usage from these two which appears to be a bug

    Can you provide a screen of the page prior to the one you showed after a long discharge?

    Thanks in advance,


  9. Hello, i hope you can do a test with App JuiceDefender?! and see if it works (results) :D.


  10. Hi, could you please state the Firmware version of your the phone? THANKS

  11. i use mine for music and a few phone calls.....brightness is down all the way and all background apps stopped......i got 18hours tops.....not that good...disappointed with the battery life so far

  12. Hi, I think you should be informed about my case. I've just bought my Samsung Galaxy S II yesterday. I consumed battery life till this afternoon when I got notified that the "Battery Is Low". I charged the battery until the battery icon is completely full. Now, I followed your instruction to see the graph. Below the graph read "3h 54m 56s". I was alarmed. Shouldn't there be "d" for days on those words like the ones in your photos?

    Thank you so much for your help.

  13. Hey @lagalag! Don't forget that it takes a few full charge cycles of the phone for it to "warm up" to normal battery usage. Also, you'll probably find that you are using it extremely heavily as you want to play with everything possible. I think as a heavy user you should expect to get about 24h out of the phone, but if you're talking to people for 4Hours solid you should expect it to drop a lot faster! For the first few charges, turn the phone off before you charge it fully overnight. I hope it improves for you over the next few weeks!

  14. Thanks for supplying us with this kind of information. :)
    Cash for cell phones available at

  15. am having a hard time believing this, as my phone wont last the day under moderate usage!

  16. I noticed you took your picture using a camera. You realize you can take a screenshot from your S2 by holding the home button and power button simultaneously, right?

  17. Great post with nice details. I really like this with nice battery life. Thanks for sharing. samusung galaxy