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Help How hot is too hot?

Nick33

Member
Aug 28, 2013
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Hey fellas, i know this topic has been beat to death, but my s4 gets hot, i mean really hot. I had an external thermometer to the back of the phone (granted, i was only browsing the Web with a few apps open in the background) and it was 110 degrees... I KNOW it was much hotter than that due to the method i was using lol.
I know phones heat up, it's fact i suppose, but to this extent? It's so random too. Sometimes its fine, but like right now, it's heating up all around the camera, and all im doing is typing in here... Wtf?! :mad:

Can u guys recommend a good app to monitor my cpu temp? Im rooted so
 
I do not recall the app, but when my s4 was getting hot I called tech support, and they told me wat app to download to get he temp. Mine was at 119 degrees. I was told the batter was defective, and they sent a replacement battery. Since they replacement came I have not had an issue with it getting hot.
 
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The phone's temperature sensor shows the temperature of the phone's battery. Because it's the phone's most sensitive component.

The Li-Ion battery's temperature upper limits are
for discharging up to +60C (+140F)
for charging up to +45C (+113F).

The processors operating temperature upper limit is a lot of higher than the battery's.

You'd use Battery Monitor Widget for monitoring the battery's temperature, even at a graph by time.

Harry
 
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My S2 used occasionally to get very hot to the extent that it actually started to feel painful if I held my finger to the hottest part. I don't think that should happen with a phone so each time it did, I rebooted and that worked every time. I have only had to do this once with my S4 and it definitely wasn't as hot as my S2 used to get.

In answer to your question, I'd say that too hot is when it gets uncomfortable to touch. If that happens regularly, something is definitely wrong.
 
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It actually does get uncomfortable. I mean i don't even want to hold the phone to my face to make a call...
U know, I've been having more than a few issues with this device. Im thinking about trying to get a new one sent to me, but i have verizon and do not want a refurb... Ive had the phone 2 months exactly today.
 
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The phone's temperature sensor shows the temperature of the phone's battery. Because it's the phone's most sensitive component.

The Li-Ion battery's temperature upper limits are
for discharging up to +60C (+140F)
for charging up to +45C (+113F).

The processors operating temperature upper limit is a lot of higher than the battery's.

You'd use Battery Monitor Widget for monitoring the battery's temperature, even at a graph by time.

Harry

Harry, the battery is the most sensitive component? Wouldn't you think it'd be the cpu?
Also, just for info sake, the part of the phone that gets hot is right around the camera. It starts there until the whole upper half of the device, including screen, is burning up.
If it were the battery, wouldn't i expect the heat to be lower?
 
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Harry, the battery is the most sensitive component? Wouldn't you think it'd be the cpu?
The battery is a block of compound with an electrochemistry that's unstable enough that it can absorb and release energy easily. The cpu is a silicon crystal with a precise pattern of impurities etched into it's structure. It's a lot more heat resistant than the battery.
Also, just for info sake, the part of the phone that gets hot is right around the camera. It starts there until the whole upper half of the device, including screen, is burning up.
If it were the battery, wouldn't i expect the heat to be lower?
The battery is the most sensitive component. Doesn't mean it's the one which generates the most heat, just the one you need to be most careful about getting too hot.
 
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If your battery is getting that hot, it is very likely that it is not functioning properly.

Unless you were driving the phone pretty hard during that time (lots of apps in the background, streaming video, etc) it may be a good idea to try using a different battery for a short period of time and see if you experience the same issues with heat.
 
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The battery is a block of compound with an electrochemistry that's unstable enough that it can absorb and release energy easily. The cpu is a silicon crystal with a precise pattern of impurities etched into it's structure. It's a lot more heat resistant than the battery.

The battery is the most sensitive component. Doesn't mean it's the one which generates the most heat, just the one you need to be most careful about getting too hot.

Thank u hadron and harry. I understand what was meant by that now. So the cpu can handle a lot of heat? I'd still really like to know HOW hot it's actually getting.
The set cpu app is a few bucks in the play store, but some people say it's not reliable. Also heard that juice defender is a good app and can actually help with overheating.
Anyone have any experience with these apps?
Ughhh i just wish i didnt have the stupid verizon variant of this phone so i could just use a custom ROM! :mad:
 
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My S4 get hot really quickly too, usually within 2 minutes of use. Never used to heat up during charging but it just started. I just ordered a new battery to see if mine came with a faulty one. Phone's only 2 months old...

Zambeezi, unfortunately im just starting to think its just the nature of this phone... :(
The more i search, the more i see people saying the same thing. I just keep wondering at what point is it faulty?
For instance, the ONLY thing I'm doing right now is searching and posting on this forum and my phone is heating up... Not nearly as bad as it gets, but getting warm nonetheless. Why? (that's rhetorical)
 
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Ok, so I've seen on this forum and other about the S4 heating up for some people. I have to say that I don't have this problem. On average my phone stays around 84 to 99 degrees at all times. (When not in direct sun light.) I can play 3D games and be on the net for 30 min or so and only get to around 104 degrees. (I have an Outterbox Commuter case on as well.) What I have noticed is when the screen brightness goes up, so does the temp.

I use a 3rd party battery monitor app for the temp. Its very useful and worth looking into.
 
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... So the cpu can handle a lot of heat? I'd still really like to know HOW hot it's actually getting.
The set cpu app is a few bucks in the play store, but some people say it's not reliable...
Honestly, I don't know if the CPU's temperature is directly reachable for the OS. The CPU might monitoring its temperature by its own and acting to control it too, not needing the OS for this job.

The OS can read the battery's temperature for to take care of the battery.
So if the battery's temperature rising up -caused by CPU's heat and ambient temperature and its own warming- the phone's/battery's control takes action for to protect the battery.
If the battery's temperature rises above 45C (113F) while charging, the control will shut down charging until the battery will meet the allowed temperature range for charging ... the charging LED might flashing red&green for to indicates that.
Discharging now, the battery should be safe because it would be below its discharging temperature limit of 60C (140F).
But if the battery's temperature would increase further and rises above the battery's discharging temperature limit of 60C (140F), the phone should shut off (restarts).

As said before, the area near the CPU could have higher temperatures caused by the CPU's heat.
Actual phones' CPUs have temperature limits up to 90C (194F).

BTW, another question is the battery's life span which will be reduced by high temperatures.

Harry
 
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Zambeezi, unfortunately im just starting to think its just the nature of this phone... :(
The more i search, the more i see people saying the same thing. I just keep wondering at what point is it faulty?
For instance, the ONLY thing I'm doing right now is searching and posting on this forum and my phone is heating up... Not nearly as bad as it gets, but getting warm nonetheless. Why? (that's rhetorical)

I really hope not because I'm actually using mine less because it gets so hot. After using it I have to let it cool down before I can even have it in a pocket.

What gets me is that some phones get really hot and others don't...
 
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Honestly, I don't know if the CPU's temperature is directly reachable for the OS. The CPU might monitoring its temperature by its own and acting to control it too, not needing the OS for this job.

The OS can read the battery's temperature for to take care of the battery.
So if the battery's temperature rising up -caused by CPU's heat and ambient temperature and its own warming- the phone's/battery's control takes action for to protect the battery.
If the battery's temperature rises above 45C (113F) while charging, the control will shut down charging until the battery will meet the allowed temperature range for charging ... the charging LED might flashing red&green for to indicates that.
Discharging now, the battery should be safe because it would be below its discharging temperature limit of 60C (140F).
But if the battery's temperature would increase further and rises above the battery's discharging temperature limit of 60C (140F), the phone should shut off (restarts).

As said before, the area near the CPU could have higher temperatures caused by the CPU's heat.
Actual phones' CPUs have temperature limits up to 90C (194F).

BTW, another question is the battery's life span which will be reduced by high temperatures.

Harry

Harry and everyone, thank you so much for explaining and trying to help me out with this issue. This isn't the only problem I've been having with this device so I'm wondering if it's just plain faulty. I have sort of an "advantage" so to speak, because i have 2 brothers who also have S4's. So i have a standard to measure by. I've messed around with both their phones and neither of them are having this issue. Do their phones get warm, yes, but not nearly to the extent of mine.
I've been thinking about trying to get a new device, but I'm with Verizon and i def dont want a refurb... I mean as i said, the device is barely two months old... Like the dumbass that i am tho, i rooted. :(
So I'm not sure what I'm gonna do yet.

Harry i will def look into that app. Thank you.
If anyone has any more input, im all ears.
 
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I'm running the app on a HTC One X and a Xperia tablet, both with Tegra3 CPU. So no info about the S4, sorry.

CPU temperature isn't shown by default, you have to set it on TempMonitor's settings.
But it's done quickly and the CPU temperature is shown immediately, so you'd install and try out it easily in that 15 minutes Google Play time.
For to try out the (simple) user interface you'd install the free version. It has an other icon (look for the dev's name) and doesn't support all of of these CPUs that the paid version supports. But maybe it supports the S4 :)

Harry
 
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