Need Advice - Turn Mobile Data Off when on Wifi?

[Vitiator]

Quick question for the GS3 Power Users out there. When you are on Wifi, do you turn off mobile data? For example, let's say I want to stream music from the Wifi connection in the office, and have Sync turned on. Would it be better for battery life to turn off mobile data, and make everything requiring data on the phone to use only the Wifi connection?

I saw this thread as well, but I am on Wifi and there is still tons of 4G icon activity, so I want to see if the Android pros actually turn off mobile data:
http://androidforums.com/samsung-galaxy-indulge/417112-does-mobile-data-turn-off-when-wifi.html

I can't do what is recommended in this thread because I still want to receive phone calls and text messages:
http://androidforums.com/samsung-galaxy-s/178680-turn-off-phone-mobile-data-but-keep-wifi.html

 

[question729]

On my Incredible I would turn off the mobile data whenever I had a wifi connection. I do that now on the S3 and connection problems occur. I can't download mms messages from people because it's off. I can't even just turn 4G back on to get the mms because it just hangs when I click download. Only way I've found to bring it back is to reset the phone. All that is too much of a hassle so I've just been leaving it on despite being interested in how much battery it would save. I'm interested to see what others have to say about it though. Is the 4G costing any battery at all when a wifi connection is live?

 

[ylexot]

I found that turning off mobile data helped my battery a lot. So, I set up a Tasker profile to turn off mobile data whenever I'm connected to wifi.

 

[Vitiator]

Good to know about the potential issues, question729, and thank you, ylexot, for confirming that turning off mobile data does in fact save battery. So I am clear, is MMS the only thing that will not work with Wifi On and Mobile Data off, or are there other things that no longer work?

 

[jaymf]

I thought that once connected to wifi, mobile data is already disabled unless it is absolutely needed (MMS). From what I recall on my Incredible, if wifi was on, I never saw the 3G symbol unless I was receiving MMS. On my S3, I believe that when I'm connected to wifi, it shows the mobile network as not connected (or something like that).

Edit: Wanted to mention, I don't think I've seen the 4G pop on while I'm on wifi with the S3.

 

[rehpyc]

I've noticed on multiple occasions that my battery will drop a lot quicker keeping mobile data on compared to not. Luckily I use GV for text and not native texting, so I don't have to worry about not getting texts.