Which Uses More Battery: 3G or Wifi?

Discussion in 'iPhone' started by jmo1116, Feb 9, 2011.

  1. jmo1116 macrumors regular

    May 27, 2010
    Just wondering if 3G or Wifi uses more battery life on a regular basis?
  2. JRoDDz macrumors 68000


    Jul 2, 2009
    Per apple, battery is better with Wifi than with 3G. So 3G uses more power.
  3. Eleonardo macrumors newbie

    Feb 29, 2008
    Definitely 3G uses more battery, but my question is then, why does WiFi go to sleep some time after you lock the phone?

    Is it because as long as no data is actively flowing, then 3G doesn't drain the battery and there is no sense in having two data oriented radios on if no data is actually being used? I guess that's the only thing that would make sense, but I'm no expert.
  4. BlackViper macrumors member

    Mar 2, 2010
    Depends on usage

    Wi-Fi uses less power but it will draw some power when it is on whether you use it or not. It is my experience that you may get better battery life leaving Wi-Fi off and only using 3G. This will depend on how much data you are using at a time and how good your cellular signal is.
  5. aldo82 macrumors regular

    Feb 8, 2011
    Because its a mobile phone maybe? You want celular connection to remain active at all times but wifi is only used when you need it. I think it is sensible for wifi to disconnect when the phone is asleep to save power if its not actually doing anything
  6. Eleonardo macrumors newbie

    Feb 29, 2008
    Ya, I guess it's a GSM thing. I know for CDMA phones running Android, it is better to leave WiFi on even if not in use as long as you have a known/reliable WiFi connection nearby because it then turns off the battery eating 3G (EvDO) radio and specifically uses WiFi for data. When WiFi becomes disconnected and/or turned off the 3G radio resumes it's role seamlessly.

    But oh well, I use the jailbroken app called iControl to help a bit with this. Still can't fix the WiFi going to sleep thing, but at least I can set a rule that when WiFi connects up, 3G turns off and Edge is used instead for cellular functions.

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