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If I have WiFi enabled and 3G data disabled, does it save any battery relative to having both WiFi and 3G enabled? With WiFi enabled, I didn't know if 3G enabled would make any difference since it wouldn't be used.

2 Answers 2

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Short answer: yes.

It depends on the currently enabled Wi-Fi sleep mode. By default, Android disables Wi-Fi when your device goes into a sleep. In this case, 3G is the remaining mode of network communication, and it gets used by Gmail/Gtalk push notifications, etc. Obviously, this network communication takes its toll on your battery time. If you disable 3G you'll save some battery, but your device will be completely offline while in sleep.

However, if your Wi-Fi is "always on", your 3G will never be used, so it doesn't really matter if it is on or off. However, "always on" Wi-Fi is a big battery drain by itself...

Update: Note that sleep modes and sub-system energy consumption differ from phone to phone. Moreover, 3G energy consumption varies greatly, depends on which background services are enabled, proximity of the cellular tower, etc. I haven't seen any "authoritative" documentation on this subject.

I suggest you check your battery stats (in Settings -> Battery) and see how cellular communication affects your battery time overall. Usually, it is a very small percentage, so in general dialing your screen brightness a down a notch will have much greater effect on your battery life.

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  • Is there any official documentation to support this fact? I ask because it was not the reality with my phone, and I would like to improve my knowledge on this subject if my conclusions are wrong!
    – Zuul
    Jun 26, 2012 at 18:57
  • Go into Settings > Wireless & networks > Wi-fi settings , hit menu, tap on Advanced, it is in there where you can set the policy of the Wifi-Sleep. By setting the policy, some claim it can increase battery life, others say, it can cause the wifi to not properly reconnect on waking up, again, this is factoring into account of wifi chipset, kernel and drivers involved.
    – t0mm13b
    Jun 26, 2012 at 19:13
  • @Zuul: I updated my answer a bit. There is no official documentation on this subject, because it is very device-dependent...
    – haimg
    Jun 26, 2012 at 19:17
  • Yap, I was reading it :) So, my answer still stands, it does improve, at the very least for Huawei devices! Tks. +'d yours!
    – Zuul
    Jun 26, 2012 at 19:19
  • Crucially, if you're in a area where cellular signal is weak, then that's the sucker-punch, as the telephony is trying to find the nearest mast/cell tower by "hopping about over the airwaves" to get at a stable frequency and nice juice drained from the battery :)
    – t0mm13b
    Jun 26, 2012 at 19:21
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I have a Huawei U8510-1 (Android 2.3.4 Gingerbread) and when I got it my battery was having a low duration between recharges.

After some tests, by disabling and enabling stuff, the battery cycle started to last more, about 2x more, with the 3G disabled. For me was great since I always use WiFi.

But this was not enough, the battery cycle still given me a short period of time, forcing me to recharge the phone more or less every two days.

The best solution that saved my day and allowed me to really save the battery, thus increasing each battery charge cycle was this APP:

Easy Battery Saver free

It works and really makes a difference. Now I charge my phone one, max two times a week, depending on the usage. :)

So, by my personal experience, disabling 3G even if it is not being used, helps saving the battery life, but doesn't make that much of a difference compared to an APP solution.


Related reading on this subject:

what drains more my battery? wifi, dataconnection(3g) or gps. ANDROID

How to Improve Battery Life on Your Android

How to Save Battery Life on Your Android Phone by Disabling 3G

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  • I really don't think having battery monitors/widgets running, as they are counter-productive! Especially if they are badly written such as resource leaks which in turn can cause the dalvikvm to be running garbage collection a bit more than often... just saying :)
    – t0mm13b
    Jun 26, 2012 at 19:33
  • I could agree with you, but as mentioned on my answer, I've disabled the 3G and was able to double the battery life between charges, with Easy Battery Saver I've got a full week or more of battery between charges. This for me was wonderful since I talk a lot. Plus I haven't found any downsides to it!
    – Zuul
    Jun 26, 2012 at 19:37
  • Of course :) One man's treasure is another man's trash :) It all depends on the handset device, rom used, and kernel. Glad it worked for you :)
    – t0mm13b
    Jun 26, 2012 at 19:39
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    Actually, it worked on four smart Phones from my office :), I'll update the answer with their manufacturers names, current kernel, etc to help future readers.
    – Zuul
    Jun 26, 2012 at 19:43
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    Good idea :) That will help in fact, why not set up a wiki question so that the community can put in their replies?
    – t0mm13b
    Jun 26, 2012 at 19:48

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