The Samsung Galaxy S24
mseibel's profile

Teacher

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15 Messages

Wednesday, October 5th, 2016 7:01 PM

S7 Edge 4G LTE Icon Blinks and Battery Life Plummets

I have owned my AT&T S7 Edge (6.0.1, Build MMB29M.G935AUCS4API2) for many months now, and love the phone. It is better than my previous Samsung AT&T phones in all aspects: Captivate S, S3, S5. The battery life is great.

 

But.... many weeks ago, I noticed that my battery life decreased significantly, for no apparent reason. The main culprit, according to the Battery Status app, is "Cell standby". It seems to be some mode that the phone gets into, for unexplained reasons. When it is in this mode, the icon display at the top of the phone will flash the "4G LTE" icon briefly about once every 4 seconds.


Rebooting and cache clearing doesn't seem to get it out of this mode.

 

However, I did determine that this returns the normal operation:

-- Turn off Mobile Data (temporarily)

-- Restart the phone

-- Turn ON Moble Data

 

After the above, the battery life returns to normal, the Cell standby drops way down on the list of battery usage, and life is good. It often remains in this fine state for weeks at a time. 

 

While I still do not know for sure what triggers this behavior, I have a theory. I just now got a phone call and the phone is back into the "bad" mode. I can tell that some phone calls sound remarkably better than others -- and this was one of them. It came from another phone on my account (a Samsung S6), and I suspect it was VoLTE or HD voice. In any case, it was much clearer than normal.

 

But after that call ended, the flashing 4G/LTE icon and the Cell standby returned.

 

 

Any idea what the problem is? 

Master

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3.5K Messages

7 years ago

Try disabling VoLTE calling, and I bet your battery issue will go away, at least mostly.

Without debugging fully, I'd say your data off/on is temporarily interrupting VoLTE, until it recieves a valid VoLTE call, at which point it re-enables this mode.

ACE - Expert

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23.9K Messages

7 years ago

what is your signal look like where your at?  Turn off enhanced LTE services and see if that fixes the problem.  If you have 1 bar or even 2 bars of service hdvoice will drain a battery dry.

Teacher

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15 Messages

7 years ago

Turning it off may work, but is that really how this is intended to function?

 

Remember -- I go WEEKS without a problem, then it seems like the drain (and flashing icon) begins once I receive a phone call. That is bizarre. It isn't like I turned on Enhanced LTE and suddenly had problems.

 

Right now I have a 2 bars (not great, but I do have a signal) and "Enhanced LTE Services" disabled but the 4G/LTE icon is flashing once per 4 second. If I have a stronger signal, full-bars, it doesn't change this icon behavior.

 

I think this problem began either with an Android update or else my local AT& network changed features.

 

 

Master

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3.5K Messages

7 years ago

 Without making any "evidence backed" claims, I'd venture to day that "Enhanced LTE Services", or VoLTE isn't exactly ultra-stable, at this point.

 

I agree, it should "just work", and ideally it would disable Enhanced mode, if the signal got low, or similar, but I don't think it's been very well "tuned", on most devices, yet.

 

In terms the 1-2 bars comment that @GLIMMERMAN76 made, that has more to do with the fact it's still negotiating and pushing packets through, and on a weak signal (low dBM), it can have to retry a LOT, in order to keep things in sync.  This will undoubtedly be very battery-intensive.

Contributor

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2 Messages

7 years ago

I am finding the same issue and it has cut my battery life nearly in half. I have tried disabling the Enhanced LTE and rebooting the phone to find that the same issue persists and the battery life has had no significant reduction in the amount of drain. This is a huge issue in that I do not have access to a charger throughout the day.

Teacher

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15 Messages

7 years ago

If this is indeed the same issue, something I read about elsewhere and stated above get the phone back into a healthy mode, at least until another HD call occurs (my theory).

 

Are you seeing the 4G/LTE icon blink once per 4 seconds? That seems to be correlated perfectly with the "bad" mode and the excessive battery drain here.

 

The fix, repeated here:

 

However, I did determine that this returns the normal operation:

-- Turn off Mobile Data (temporarily)

-- Restart the phone

-- Turn ON Mobile Data

Master

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3.5K Messages

7 years ago


@mseibel wrote:

If this is indeed the same issue, something I read about elsewhere and stated above get the phone back into a healthy mode, at least until another HD call occurs (my theory).

 

Are you seeing the 4G/LTE icon blink once per 4 seconds? That seems to be correlated perfectly with the "bad" mode and the excessive battery drain here.

 

The fix, repeated here:

 

However, I did determine that this returns the normal operation:

-- Turn off Mobile Data (temporarily)

-- Restart the phone

-- Turn ON Mobile Data


@mseibel@wiccandragon, Even if this is true (turning off Enhanced LTE isn't sufficient in-of-itself), you still will want to disable Enhanced LTE, as part of the process:

-- Turn off Enhanced LTE

-- Turn off Mobile Data (temporarily)

-- Restart the phone

-- Turn ON Mobile Data

 

 

If you don't do this first, and you simply enable/reboot/re-enable data, then at some point (sooner than later, as VoLTE gets more pervasive), you'll simply fall back into the same high-drain mode.

 

Hopefully there will be some algorithmic changes coming in this area, clearly there is work to be done, to properly handle VoLTE switching.

Contributor

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2 Messages

7 years ago

As a matter of happenstance, through some additional testing of my own, I am finding that by disabling the WiFi Calling feature that this has posed some resolution for me as well. The network to which I am attached while at work does not provide me the ability to connect to WiFi Calling and that seems to coordinate to the issue that I am having. I noticed this first when WiFi Calling stopped connecting at home and the "flicker" returned, the battery rapidly began to drain again. In disabling WiFi Calling I have prolonged my battery life once again.

Teacher

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15 Messages

7 years ago

Well it seems like there are several triggers and workarounds to this problem. I do not have WiFi Calling enabled, yet I still had this problem.

 

But the common denominator of the flickering 4G/LTE icon and greatly increased battery life sure seems like the same root cause, whatever that might be.

Teacher

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15 Messages

7 years ago

> you still will want to disable Enhanced LTE, as part of the process:

 

Forcing us to pick between clear phone calls and recharging by noon is an sad choice.

 

Hopefully the AT&T|Samsung|Google|4G-Committee or whoever in the food chain that is responsible will get this working better soon. Or maybe they are they all busy working on 5G.

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