Originally Posted by Kie
My S4 is getting quite hot without gaming. I'm guessing it's the downloading/installing apps that's doing it. Waiting for my case so I can ignore the issue
Probably, you're fine, but you reminded me that I wanted to give this little...
This post is especially for everyone new to Android, or new to a phone with multiple cores, like this SGS4.
On occasion, your phone can run hot, caused by -
- Something expected:
- an app that really pushes it all to the limit, like an intense game
- some short term combination of apps that can get things very busy
- Or - a mysterious abnormal case that seems to come and go - please click the Show button for a quick explanation of that -
From a similar thread in another forum, where the phone (HTC One) was observed to get hot, battery drain quickly, and then not happen again - a mystery.
That can happen to you with an SGS4 (or SGS3 or whatever), here's why -
Originally Posted by EarlyMon
Probably a runaway app, most likely what we call a race condition. Apps naturally parallelize using constructs that we call threads. Think of it this way - for listening to music, the app may have a thread for the display updates, a thread to sense inputs and one for actually playing music. (That's an insanely simplified fictional example, but good enough for the idea - threads can run in parallel.)
And quite often, threads will rendezvous with one another for control purposes.
Every so often, you get a bug where they won't, they just hang waiting for each other.
Or, you can get the condition where they spin out of control missing the rendezvous at top speed - and Android will automagically distribute threads across CPU cores. And spinning threads racing each other can and will do that across multiple cores at top speed. Drawing max power and dissipating it as heat.
If it comes back, you have a flakey app somewhere.
If it doesn't, you could have just had a single bit in ram stuck for a while, and coincidentally at the point that would induce the race condition.
If your phone persists in running hot and there seems to be no reason for it - you're not pushing it hard or running a hard app - please consider immediate service or replacement if new.
Heat is usually caused by the main processor or the radio transceivers.
The place where you need to worry about heat is your battery.
Batteries can heat from -
- rapid power dissipation (fancy word for - battery losing power quickly)
- common Android example - using GPS navigation with the typical other goodies at the same time, especially on a summer day
- forcing your phone back on when it wants go off from low power and running it anyway (related to the first bullet)
- heat transfer from the motherboard goodies (processor, etc etc)
Reliable reports say your battery should be ok up to around 50 degC, aka 122 degF.
This handy app will tell your battery temperature, if there isn't a way on-board this particular phone to tell - Elixer 2, it's free
- just tap the information button in the upper left when it launches.
Prolonged high heat to your battery, especially near its upper limit, will cause the internal metal structures to deform. The more a battery is pushed that way, the sooner it dies and needs replacing.
Pro Tips On That:
Safety Tip On That:
- If you're enjoying the replaceable battery feature on your SGS4 and find you have to swap it a few times per day (and that's more than normal for those of us who travel in and out of - or work in - areas with lousy coverage) then don't wait until your first battery is drained to do the swap. Head it off at the pass. Swap when it's at 20% or so if that's convenient.
Cool down Do's and Don't's -
- A seriously overworked or abused battery will actually swell up - it will bloat, you can see it.
- A lot of people don't believe this.
- A lot of people believe it's some weird myth.
- It's true.
- Remember above I mentioned the metal structures deforming? Left to the extreme, they'll get so out of whack that the battery will physically swell up to accommodate the weird reshaping of the metal bits, along with whatever strange chemistry is going on inside to accompany that.
- Never use a swollen battery.
- When using a swollen battery - don't!
- They're dangerous.
- No kidding, actually dangerous.
- Don't charge it.
- Don't use it.
- Replace it immediately.
Ok, I didn't see the article mentioned where a reviewer put the phone in the freezer for testing.
put your phone in the freezer.
- The rapid transition to a sealed cold environment can very easily cause rapid condensation of normal air moisture, trapped in your phone, to go to water and even ice crystals.
- What happens when you put a bit of water on a powered-up little motherboard?
- If you're lucky, nothing.
- If you're like the rest of us - an electrical short.
- If you're lucky, nothing is damaged.
- If you're like the rest of us, your phone is damaged.
consider safe ways to rapidly cool down an overheated phone -
- At home:
- Bag of frozen peas or similar
- Kitchen towel on top of that, doesn't need to be thick
- Phone on top of that
- In the car:
And on that note, you'll find that many car holders come either with articulating arms so you can get some air flow on your phone, or actually mount your phone to an air vent. Handy for those driving in and out of cell service (working the battery) and using GPS (working the battery some more) on those hot summer days.
To many of you, this is all old hat and (jeez Early, why the freaking wall o' text
) - but for our many newcomers to the Samsung Galaxy S4 and the world of Android super-powered phones, I hope this helps.
Cheers and thanks for reading.