What actually uses more battery power - WiFi or 3G ?

Question

Level 1

5 points

What actually uses more battery power - WiFi or 3G ?

I've read conflicting thoughts, so I wanted to ask which actually uses more battery power - WiFi or 3G ?

Does anyone leave WiFi disabled all the time?

MacPro 1.1, 3GHz, 2 Dual Cores, Mac OS X (10.5.8), MacBook Pro, iPhone 3GS (3.1.2)

Posted on Oct 30, 2009 10:03 AM

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Answer 1

Oct 30, 2009 10:08 AM in response to smilingdog

In my experience with everything being equal - full or a strong wi-fi connection/reception and full or strong 3G reception, actively accessing the internet via 3G will consume more battery than actively accessing the internet via wi-fi. When 3G reception is low or lower, more battery will be used.

I rarely turn wi-fi access off.

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Answer 2

prk60091

Level 1

40 points

Oct 30, 2009 10:44 AM in response to smilingdog

without a doubt 3g burns more battery than wifi

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Answer 3

Oct 30, 2009 10:47 AM in response to smilingdog

If you try something like "Battery Magic" or any one of the dozen or so battery tracking apps in the app store, they will predict about twice as much wifi internet time as 3g internet time for any given charge remaining.

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Answer 4

Oct 30, 2009 11:25 AM in response to smilingdog

I've had the same experience (3g using more battery than wifi) I've noticed that persistent programs, such as instant messaging programs, tend to use about equally regardless of connection type, but maybe this has to do with the bulk of said battery usage being program and not internet.

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Answer 5

Oct 30, 2009 11:31 AM in response to SwerdMurd

Be nice if an engineering type would give some specific figures. But I seem to remember that a wifi transceiver is running in the couple-of-hundred milliwatt power range, while a 3G cell phone is something like 0.5-1.0 watts, so it only makes sense that using the cell phone radio would drain the battery much faster.

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Answer 6

smilingdog Author

Level 1

5 points

Oct 30, 2009 4:28 PM in response to Michael Black

Thanks for all your responses. I suspected WiFi used more power and you guys confirmed that.

BTW - Michael, 0.5 watts is 500 milliwatts... so you're off base with the comparison of the couple-of-hundred milliwatts for wifi vs. 0.5-1.0 watts for 3G. Excuse me... I used to be an engineer 😉

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Answer 7

Oct 30, 2009 4:38 PM in response to smilingdog

Actively accessing the internet via 3G will consume more battery than when actively accessing the internet via wi-fi - in my experience anyway using a 3G for over a year now.

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Answer 8

Oct 30, 2009 5:29 PM in response to smilingdog

Yes, I know. Googlin' for it, I found reports that a typical wifi transceiver is in the 100-200 millliwatt range, and a cell phone radio can be up to 1.0 watts (500 to 1000 milliwatts), so the 3g radio is using 2.5x - 5x as much power as the wifi.

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Answer 9

Sandman

Level 4

3,274 points

Oct 30, 2009 8:38 PM in response to smilingdog

it's the opposite.. WiFi uses LESS power.. as the above posts suggest..

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Answer 10

Oct 31, 2009 2:41 PM in response to smilingdog

Quoted from http://www.apple.com/iphone/specs.html

+Internet use:+
+* Up to 5 hours on 3G+
+* Up to 9 hours on Wi-Fi+

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