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hypno

macrumors regular
Original poster
Oct 30, 2012
181
1
This might be something many of you are already doing, but if you get in areas of low cell signal (i.e. Your office building) and you have WiFi access you can just turn on Airplane mode, which disables everything, and then turn WiFi back on (swipe up, hit airplane, hit wifi). I've done this the last two days at the office and my battery life is significantly better...at least twice as good.

It makes sense after speaking with some folks on the iOS board - T-Mobile WiFi calling no longer disables the cellular modem (it used to with Android) so that you can have seamless transfers from WiFi to LTE. However in areas of low signal where you don't need this feature it can also beat up on your battery.

When you're leaving you can just swipe up and turn airplane mode off.

Anyway just sharing what I learned in case it helps some others like me.
 
Sorry, I don't mean to attack the TC in this case. But the pure lack of common sense on the boards this past week is astonishing.
 
I don't mind that you think I'm an idiot. I'm well paid and highly successful in my IT profession. What is even more astonishing is how holier than thou some people can be on these boards when I'm simply trying to help others who came over from Android like me and were not aware of how WiFi calling has been changed for this platform.

Don't forget you always have the choice to be nice to people, no matter how stupid you think they are.
 
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This might be something many of you are already doing, but if you get in areas of low cell signal (i.e. Your office building) and you have WiFi access you can just turn on Airplane mode, which disables everything, and then turn WiFi back on (swipe up, hit airplane, hit wifi). I've done this the last two days at the office and my battery life is significantly better...at least twice as good.

It makes sense after speaking with some folks on the iOS board - T-Mobile WiFi calling no longer disables the cellular modem (it used to with Android) so that you can have seamless transfers from WiFi to LTE. However in areas of low signal where you don't need this feature it can also beat up on your battery.

When you're leaving you can just swipe up and turn airplane mode off.

Anyway just sharing what I learned in case it helps some others like me.

Yup, I do the same thing sometimes :)
 
I was also curious whether or not going to wifi calling really saves battery or not. So basically, even with that on the cellular modem continues to drain the battery in an equal amount as if wifi calling was off?

I have been disappointed with the battery on my 6 and maybe the signal is the issue, though I usually have a few bars. I'll try this and see if it works.
 
I was also curious whether or not going to wifi calling really saves battery or not. So basically, even with that on the cellular modem continues to drain the battery in an equal amount as if wifi calling was off?

I have been disappointed with the battery on my 6 and maybe the signal is the issue, though I usually have a few bars. I'll try this and see if it works.

Yeah. With the Android version of WiFi calling it always disabled the cellular modem automatically for you whenever you got on WiFi networks. Perhaps this has changed with Android now that they are rolling out new WiFi calling updates to the major phones since Uncarrier 7. I have all my Android phones reloaded and ready to sell. I imagine they had to change it at this point otherwise you cannot have seamless transfer from WiFi to LTE if the cell modem is of course disabled.

It is really a root cause of being on the TMobile network until they get lower band up and operational. At my workplace and even at my home, my signal fights between 1-2 bars of LTE to 4G to even Edge sometimes all day long.

I'm still at 100% with nearly 5 hours of standby and 34 minutes of usage today. Pure standby was draining my battery much faster than this with the cellular modem enabled.
 
Do you need to enable wifi calling anywhere though, or is it just a basic feature that isn't to be toggled?
 
Being a millennial, I don't know what "Calls" are, but once I get my device, I am looking forward to anything that saves my battery! :p
 
This might be something many of you are already doing, but if you get in areas of low cell signal (i.e. Your office building) and you have WiFi access you can just turn on Airplane mode, which disables everything, and then turn WiFi back on (swipe up, hit airplane, hit wifi). I've done this the last two days at the office and my battery life is significantly better...at least twice as good.

It makes sense after speaking with some folks on the iOS board - T-Mobile WiFi calling no longer disables the cellular modem (it used to with Android) so that you can have seamless transfers from WiFi to LTE. However in areas of low signal where you don't need this feature it can also beat up on your battery.

When you're leaving you can just swipe up and turn airplane mode off.

Anyway just sharing what I learned in case it helps some others like me.

I use a Verzion iPhone 6 on t-mobile's network and I agree with your observation. My battery life seems to double when I use airplane mode + wifi calling.
 
Do you need to enable wifi calling anywhere though, or is it just a basic feature that isn't to be toggled?

Settings - Phone - Wi Fi Calls - Allow Wi-Fi Calls

After you toggle this on, you'll see "T-Mobile Wi-Fi" up top when it's working.

----------

Being a millennial, I don't know what "Calls" are, but once I get my device, I am looking forward to anything that saves my battery! :p

Just keep in mind this is a tradeoff. If you forget to take it out of Airplane mode you'll lose out of seamless call transfer from WiFi to LTE of course. Like you, though, I'm just not on the phone as a phone enough to care. I wish we had the option to tell WiFi calling to work this way by default.
 
My battery drains like crazy when in a building. Many parts of my town aren't evenly blanketed by T-Mobile. Some areas are fine, others are total dead zones.

I'll try this when I'm at work and see what happens. I didn't realize than you can even text over wifi. I guess visual voicemail works too?
 
This might be something many of you are already doing, but if you get in areas of low cell signal (i.e. Your office building) and you have WiFi access you can just turn on Airplane mode, which disables everything, and then turn WiFi back on (swipe up, hit airplane, hit wifi). I've done this the last two days at the office and my battery life is significantly better...at least twice as good.

It makes sense after speaking with some folks on the iOS board - T-Mobile WiFi calling no longer disables the cellular modem (it used to with Android) so that you can have seamless transfers from WiFi to LTE. However in areas of low signal where you don't need this feature it can also beat up on your battery.

When you're leaving you can just swipe up and turn airplane mode off.

Anyway just sharing what I learned in case it helps some others like me.

Didn't think about trying that. I'm usually in a building underground for half the day during the week and it drains battery quickly. I'll try this out tomorrow thanks.
 
Do you always have the "T-Mobile Wifi" signal on when it is in the wifi mode? I realized somethings when the phone is off, the wifi signal is also off.
 
That's a good question. I wonder if you have wifi calling on, but the phone is in airplane mode, after a while, will the wifi radio automatically go into sleep mode? Ugh, if so, we're screwed if we try this idea.
 
That's a good question. I wonder if you have wifi calling on, but the phone is in airplane mode, after a while, will the wifi radio automatically go into sleep mode? Ugh, if so, we're screwed if we try this idea.

WiFi connection in sleep mode appears to be persistent (presumably in a low power state) when cellular is turned off this way. Just tested it, call from our landline went right through and the iPhone's screen woke up.

I typically only have one bar in most of the house unless I'm right next to a window, which was part of why I upgraded from an iPhone 5... WiFi calling is pretty much a necessity in this place. This trick should definitely help my battery life!
 
Thanks for the tip OP! Half my classes are in basements where no one gets signal so I've been using wifi calling since it became available. Had no idea it would still work with airplane mode turned on before toggling on wifi.
 
Actually, this makes me think of something. Would this same technique work outside the US? As in I could visits another country, enable airplane mode, connect to WiFi, and use my iPhone like I'm still here in the US?


(apologies for the thread hijack, op. The thought only occurred to me after seeing your post)
 
That's a good question. I wonder if you have wifi calling on, but the phone is in airplane mode, after a while, will the wifi radio automatically go into sleep mode? Ugh, if so, we're screwed if we try this idea.

I put my phone in airplane mode all the time and I haven't noticed that the WiFi turns off after extended periods. I can still get calls & texts like normal.

----------

Actually, this makes me think of something. Would this same technique work outside the US? As in I could visits another country, enable airplane mode, connect to WiFi, and use my iPhone like I'm still here in the US?


(apologies for the thread hijack, op. The thought only occurred to me after seeing your post)

The short answer is yes you can if you're a TMO subscriber. More details here.
 
I'm astounded that people are amazed turning off the cellular modem saves battery...

Yes enabling airplane mode and only using WiFi with WiFi calling will save battery, but you won't have a seamless transition between the GSM and WiFi networks until you turn off airplane mode. You need to remember to toggle this every time you go in and out of WiFi range.

As for Android, no it does not disable your cellular modem. You'd have to do that manually.
 
I'm astounded that people are amazed turning off the cellular modem saves battery...

Yes enabling airplane mode and only using WiFi with WiFi calling will save battery, but you won't have a seamless transition between the GSM and WiFi networks until you turn off airplane mode. You need to remember to toggle this every time you go in and out of WiFi range.

As for Android, no it does not disable your cellular modem. You'd have to do that manually.

I think most of us knew that. It's just that many didn't know Wi-Fi Calling was fully usable while in Airplane Mode.

Thanks again to the OP. I tried this today and got home with 7 hours of usage, 9 hours standby with 40% battery life remaining. Regular iPhone 6 not the Plus.
 
I think most of us knew that. It's just that many didn't know Wi-Fi Calling was fully usable while in Airplane Mode.

Thanks again to the OP. I tried this today and got home with 7 hours of usage, 9 hours standby with 40% battery life remaining. Regular iPhone 6 not the Plus.

I tested it today. Worked like a charm.

Went to work at 7:30am with 100%, came back from work at 5:30pm with 83%. This saved so much battery. Judging from the drop in battery, I don't even need to charge my phone tonight and it will last the whole day tomorrow. I am going to try that.
 
This is toward the end of day number 2, 8:48pm, and I still didn't charge my phone, I am still having 8% battery. Wifi calling really save battery.
 
Just to note, if you originate a wi-fi call on a 5s, it will NOT seamlessly transition over to the cellular network like it will on the 6/6 Plus.

I have a 5s and anecdotally noticed some battery life improvement after enabling wi-fi calling. However, I still see the signal strength dots for the celluar network, so I don't know if it's the wi-fi calling or something happening with an iOS 8 update or just my imagination. When the OP noted that wi-fi calling used to shut off the cellular modem, I wondered if that's what Apple did with the 5s. Who knows.
 
Just to note, if you originate a wi-fi call on a 5s, it will NOT seamlessly transition over to the cellular network like it will on the 6/6 Plus.

I have a 5s and anecdotally noticed some battery life improvement after enabling wi-fi calling. However, I still see the signal strength dots for the celluar network, so I don't know if it's the wi-fi calling or something happening with an iOS 8 update or just my imagination. When the OP noted that wi-fi calling used to shut off the cellular modem, I wondered if that's what Apple did with the 5s. Who knows.
Voice over LTE is not enabled on the 5S, so there will not be seamless transition. This is enabled by Apple in the baseband firmware. Only Apple can enable this.
 
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