Does having Wifi toggled on, but not in use waste battery?

michael31986

macrumors 68040
Original poster
Jul 11, 2008
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i always keep my wifi toggle on, but its not connected to any wifi at work...does this still waste battery?

also i keep my phone at 80/85 percent brightness that would def. decrease battery life right?
 

admanimal

macrumors 68040
Apr 22, 2005
3,531
2
The best thing to do, short of turning off WiFi completely, is to turn off Ask To Join Networks. This way it will automatically connect to known networks, but won't waste power trying to find one to connect to otherwise.
 

michael31986

macrumors 68040
Original poster
Jul 11, 2008
3,803
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I have ask to join networks off. But even with that toggled off it wastes battery? I thought haven't wifi on but the automatic ask to join off was the same as havoc wifi off.
 

admanimal

macrumors 68040
Apr 22, 2005
3,531
2
I have ask to join networks off. But even with that toggled off it wastes battery? I thought haven't wifi on but the automatic ask to join off was the same as havoc wifi off.
Not quite, because it still has to power the WiFi chip in order to search for your known networks. The difference is that it doesn't waste power trying to negotiate a connection with unknown networks.
 

tzag

macrumors member
Jun 22, 2010
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0
In all of the tests that Apple does to determine battery life, they leave WiFi on but not connected to a network. It of course does take a bit of juice but not a significant amount.
 

michael31986

macrumors 68040
Original poster
Jul 11, 2008
3,803
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so far i have 3 hours and half and 18 hours stand by. i charged mine at night and unplugged it, so basically it hasnt' been charged since last night at around 12midnight. i watched a full movie at work and i browsed a bit talked only a little and texted.

i stil have 34% left on my battery. is this normal for iphone 4? my brightness is at. 55/60
 

jdong

macrumors member
Nov 24, 2008
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0
Nobody's pointed out how much more power transferring some data over 3G takes compared to wifi. Sure, you might lose some battery from a couple wifi scans now and then, but comparing that to firing up the 3G data connection for downloading an email, you'll probably break even.
 

-aggie-

macrumors P6
Jun 19, 2009
16,795
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Where bunnies are welcome.
In all of the tests that Apple does to determine battery life, they leave WiFi on but not connected to a network. It of course does take a bit of juice but not a significant amount.
This. Better to leave it off, if you don’t need it, but if you forget it’s not going to be a big deal.

Nobody's pointed out how much more power transferring some data over 3G takes compared to wifi. Sure, you might lose some battery from a couple wifi scans now and then, but comparing that to firing up the 3G data connection for downloading an email, you'll probably break even.
No, using 3G will almost double you battery loss over time.
 

Megalobyte

macrumors 6502a
Dec 30, 2007
690
119
Florida
How about the reverse? let's say you're home, connected to your network, but you leave 3G on, even though you're not actively using it, ie. your surfing is wifi, and you're not using the phone?

I usually leave wifi on and 3G off at home, when I get in my car I switch, and turn 3G on and wifi off.

Still curious about having 3g on but using wifi, is simply having 3G on draining your battery?
 
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