Battery drain due to Mobile Data

[rimz808]

So I have been struggling to find out what is causing my battery to drain so quickly, especially once it gets off the charger in the morning after being charged over night.

I decided to manually turn off Mobile Data and I've noticed that my battery hasn't drained as quickly as it has been with it on. It's now been about 1 h and 30 mins on battery, and it only has drained 9%. Usually after the 1 hour mark, I would be in the 80s percent.

My question is, isn't Android suppose to use the Wi-FI connection over Mobile data if a wi-fi connection is present? Why would manually turning off mobile data cause the battery drain? Is there a setting I'm not seeing to allow wi-fi over mobile data?

Thank you for your help,

 

[B. Diddy]

How is your cell signal overall? If it's poor, the phone will still eat up battery even if you're on wi-fi, because the cell radio is still trying to latch onto signal. This happens to me as well in my workplace. If you're able to use wi-fi calling with the cell radio off, you could consider turning on Airplane Mode while you're in the area of poor signal, and then turning wi-fi back on.

 

[rimz808]

How is your cell signal overall? If it's poor, the phone will still eat up battery even if you're on wi-fi, because the cell radio is still trying to latch onto signal. This happens to me as well in my workplace. If you're able to use wi-fi calling with the cell radio off, you could consider turning on Airplane Mode while you're in the area of poor signal, and then turning wi-fi back on.

Correct me if I am wrong in finding out my cell signal, but do I go into Settings > About Phone > Status SIM card Status > Signal strength? If so. the signal that I see when at both at work and at home, it's around -100dBM, which after looking it up, is NOT a good number to see. I am on ATT. I asked my co-worker who has a S8 phone, but on Verizon, and he gets -70.

I am using an unlocked phone and because of that, I cannot use Wi-Fi calling, which is fine because I can still get calls and text when I turn off my Mobile data.

However, why am I getting such a weak signal? Is this something I need to contact ATT about?

 

[B. Diddy]

Android devices used to have a decent cell signal strength indicator in the Battery menu, but for whatever reason, most manufacturers got rid of it. GSam Battery Monitor is the next best thing, so try installing that and show us the cell signal strength graph over the course of a whole battery charge. -100 dBm isn't great, but it's important to see what the signal is over time.

There are a number of reasons for poor signal. The main one would be how good the carrier's coverage is in your area, which directly correlates to the concentration of their cell towers. Other factors include which network bands those towers use and what frequency they're at (higher frequencies don't penetrate into buildings as well as lower frequencies). Even certain cases can interfere with reception, especially those that have any metal in them.

 

[claykin]

-100dbm is a weak signal. Phone is racheting up the transmitter power to keep you connected. at&t won't do anything for you. They'll recommend switching to wifi calling, which your unlocked phone doesn't seem to support.

check out Tmobile and compare signal.

 

[srinathp1988]

I checked signal strength in settings/about/status/sim card status and it says -115dbm 24 Asu. From what I googled, this seems to be a poor signal strength. I am on at&t and i think i had poor signal on my note 5 too. probably it has to do with att and not the phone

 

[rimz808]

-100dbm is a weak signal. Phone is racheting up the transmitter power to keep you connected. at&t won't do anything for you. They'll recommend switching to wifi calling, which your unlocked phone doesn't seem to support.

check out Tmobile and compare signal.

So it is a phone issue? I am going to test my cell signal on my old Huawei phone and see what results I get. If less than -100, then I am thinking it's a phone issue?

Also, help me understand what turning off Mobile data does, because when I have mobile data off, I am still able to call and get calls, as well as send and receive text. From what I understand, I just cannot be on their LTE data, which I am on wi-fi anyways at home or office. I will just then have to turn it on when in the car or out in public areas.

What is the purpose of Wi-Fi calling then?

 

[rimz808]

I checked signal strength in settings/about/status/sim card status and it says -115dbm 24 Asu. From what I googled, this seems to be a poor signal strength. I am on at&t and i think i had poor signal on my note 5 too. probably it has to do with att and not the phone

I will go to my local AT&T store to see what they say. Maybe I will request a new SIM card.

 

[rimz808]

And BTW - I am now 8 hours on battery and I have about 53% of battery left! To me that is amazing as at this hour I would be near 20% by now.

So definitely turning Mobile Data off has improve my battery life significantly, but now just trying to figure out why my signal is so weak.

 

[B. Diddy]

So it is a phone issue? I am going to test my cell signal on my old Huawei phone and see what results I get. If less than -100, then I am thinking it's a phone issue?

Also, help me understand what turning off Mobile data does, because when I have mobile data off, I am still able to call and get calls, as well as send and receive text. From what I understand, I just cannot be on their LTE data, which I am on wi-fi anyways at home or office. I will just then have to turn it on when in the car or out in public areas.

What is the purpose of Wi-Fi calling then?

It can be a combination of AT&T coverage in your area and your phone. It's hard to tell unless you can compare with someone else on AT&T on a different phone standing right next to you.

Turning Mobile Data off means the phone can't access the web using its cell radio -- it would have to rely on wi-fi. But turning off Mobile Data doesn't turn off the cell radio completely, so the phone can still make and receive phone calls and SMS texts (but not MMS, which requires mobile data).

 

[claykin]

So it is a phone issue? I am going to test my cell signal on my old Huawei phone and see what results I get. If less than -100, then I am thinking it's a phone issue?

Also, help me understand what turning off Mobile data does, because when I have mobile data off, I am still able to call and get calls, as well as send and receive text. From what I understand, I just cannot be on their LTE data, which I am on wi-fi anyways at home or office. I will just then have to turn it on when in the car or out in public areas.

What is the purpose of Wi-Fi calling then?

Unlikely a phone issue. Probably distance from cell tower and/or construction of building possibly blocking signal. How is signal outside?

Reason turning off mobile data helps battery is because radio only sends pings to keep connected while idle. If it has to send data then radio stays on full power in a sustained fashion to complete your data transaction. This burns battery. Very likely if you sat on a long phone call, you'd also see the battery deplete quickly just like you had mobile data enabled. Or worse!

Wifi calling allows you to push both voice and data to your local wifi, thereby idling the cell radio.