Develop Bugs

[Q] So switch to wifi when I'm at work or not?

What saves more battery? Leaving my phone on wifi at work, or just letting it run on the hspa network? The wifi is a little bit faster.

durps said:
What saves more battery? Leaving my phone on wifi at work, or just letting it run on the hspa network? The wifi is a little bit faster.
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WIFI saves battery: Heres a thread just like yours check it out almost the same title too: "Using WiFi in the office instead of 3g for better battery life?"
http://forum.xda-developers.com/showthread.php?t=904033

wifi actually saves battery, but really depending where you are. I am always on wifi and i seem to be fine on battery. The constant data switching between speeds tend to lower battery faster than wifi
sent from my V I S I O N.

Yes I can attest to it also, I've went WELL over 30 hours (I think unplugged on a Saturday at 5pm, and then still had 10% left on Tuesday afternoon) on Wifi whenever possible, and using Edge with no background sync when I was out of a wifi range. I would post a pic but didn't take it, and this seems to doesn't work on CM7 for me, not even after wiping battery stats.

Overheating problem?

When I have my phone plugged in and am tethering 2 worrying things happen.
A. The phone drains battery VERY VERY quickly, (yes even when plugged in). Quickly I mean like 20-30 percent in half an hour.
B. The phone starts to get very very hot. So hot that when I turn it off, it does not let me charge and instead the overheating icon flashes. If I leave it on, the screen and the capacitive touch buttons start to flash erratically and the back gets even hotter.
This kind of frightens me, is it happening to anybody else? If so can you please post. Also I am using Blazer ROM 3.8 if that makes a difference. Please reply thanks!

How are you tethering? Through usb or wireless hotspot? Are you tethered while on 3G or 4G? How is your signal while tethered? All these things are relevent so answer these these questions so we can offer you some advice.

tx_dbs_tx said:
How are you tethering? Through usb or wireless hotspot? Are you tethered while on 3G or 4G? How is your signal while tethered? All these things are relevent so answer these these questions so we can offer you some advice.
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Thanks for the quick reply. I am tethering through the Sprint Wifi Hotspot on 4G. I have 2 bars on 4G when I am doing this.
Need anything else?

rapman543 said:
Thanks for the quick reply. I am tethering through the Sprint Wifi Hotspot on 4G. I have 2 bars on 4G when I am doing this.
Need anything else?
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Check your task manager and see how many apps you have eatting at your CPU.....and are you overclocked?....if yes...don't overclock while teathering
sent from the near past

what rom you on?? When I was on blazer 3.8 it was like you stated. Since I've been on 3.9 it doesn't get nearly as hot or drain as fast.
Sent from my SPH-D710 using Tapatalk

Mine overheats when using Netflix over 4G and charging. I run my phone stock and really clean with nothing extra running. Sometimes I get an image freeze and a short sound loop and I have to force shut down. But usually it just tells me that it isn't charging anymore due to the battery being too hot. The battery is always cold, but the phone is hot.
The phone runs hot. Wot wah.

I'm on 3.8 (the first version) I got really confused when he released another one the same day? I have nothing else running and I have not touched any CPU settings, so I'll just have to conclude the phone runs hot. Can this permanently damage the phone? If so what can I do to prevent that. Thanks again for the replies!

rapman543 said:
I'm on 3.8 (the first version) I got really confused when he released another one the same day? I have nothing else running and I have not touched any CPU settings, so I'll just have to conclude the phone runs hot. Can this permanently damage the phone? If so what can I do to prevent that. Thanks again for the replies!
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Heat is the phone's worst enemy. I love PH and his work but you gotta stay away from heat. It shortens the life span of your phone.
Edit: he updated it today so I'd give that a try.
Sent from my SPH-D710 using Tapatalk

Yeah get off 3.8 as soon as you can, when I did the problems you mentioned went away. BTW I'm on his latest 3.9 and it is far superior in every way...3.8 didn't like our phones too much!
Sent from my SPH-D710 using Tapatalk

i've definitely had this same exact problem.. Phone/Battery heats up (>40C) and drains quickly with 4g and wifi tethering active. I think overheating the battery like this will shorten the life of the battery in the long run.
Maybe tethering over usb is the solution. fwiw my evo used to tether 4g without this issue. im using blazer 3.9 (upgraded from 3.7, wasnt ever on 3.8) stock clocks/kernel.

Hot LIPOs are less efficient in their discharging and will drain more amp-hours than if they were cold and doing the same things. Running them hot will also shorten their life, correct.
If you battery runs hot, swap it for a cold one* and wait until your battery is cold to charge it off a wall charger or something. These low C rated batteries we use don't really get toasty from just charging, but you are wasting energy trying to charge a hot battery over a cold battery.
*Beer does not supply the minimum 3.7v

This is gonna sound super ghetto, but it's what I do and it works. When your are running your tether, have the phone plugged in, take an ice pack and a couple paper towels. Put the paper towels on top of the ice pack and your phone on top of that and you're golden for about an hour. Keeps it at a nice 25°c
Sent from my SPH-D710 using XDA App

Freeroot said:
This is gonna sound super ghetto, but it's what I do and it works. When your are running your tether, have the phone plugged in, take an ice pack and a couple paper towels. Put the paper towels on top of the ice pack and your phone on top of that and you're golden for about an hour. Keeps it at a nice 25°c
Sent from my SPH-D710 using XDA App
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sounds like it would work... but there has to be a better way. I tether at work a lot (to get around pages i use like netflix/facebook and whatnot being blocked) what i've been doing is limiting my tethering based on how warm the phone is, when it heats up past 40 i give it a rest (and get back to work).
Helping me find a lasting fix to this problem will allow me to be less productive, and hopefully extend the life of my s2.

I have been meaning to make a thread on this. It happens when tethering only, that the phone overheats.
The reason being is the power management for tether I think got bonkered with the addition of 4g tether. Something is not optimized. The battery level literally deplete 10% within minutes
I've overheated to the point where my vibration motor makes noise, and got corrupt data twice. So now I have to tether with a glass of ice on my phone, ice pack would be better.
I appreciate the tether, but the trade off is ridiculous.
.: sent from my Samsung Galaxy S II Epic 4G Touch :.

See, this is weird... I've been wondering why my phone DOESN'T heat up appreciably while tethering, w or without 4g. My og epic always would for sure. I do the same type of browsing on tether with this phone (not super intense, just browsing, but it always heated up the og epic) and the phone stays cool to the touch, or maybe just barely perceptibly warmer. Not even enough to make me check batt temp.
I'm running stock rooted, using sprint hotspot hack. No overclock. FWIW.
Sent from my SPH-D710 using XDA App

I would just take the back off the phone and have a small fan blow into it. Also I heard underclocking to 800 MHz while tethering will keep your phone cooler.

Thanks for the amazing replies people! I recently switched onto 3.9 and to calibrate my battery I charged to 100% and tethered on 4G for about 2 hours no problem. So I suppose it was just some problem with 3.8 then?

Ditto
Same thing happens to me but from daily use. I'm on the web a lot. I'm rooted but running stock rom. It's been really bad the last few days, especially after I changed the 4G idle speed. So that may be one issue for me. Oh well

I experienced the same problem , but I think it's due to tethering as the CPU is processing and forwarding more traffic . I fixed this by limiting the tethering download speed . I used an app called bandwidth ruler for that . and my samsung SIII is relaxed while tethering
APP:
Bandwidth ruler free on goolge Store
XDA thread :
http://forum.xda-developers.com/android/apps-games/app-bandwidth-manager-android-t2972889

Battery Life suggestion please

I get AMAZING battery life when I'm on wifi but terrible battery when I'm not. I send/receive about 300 texts a day easily and so I have the screen on frequently. I also use web a lot. On wifi my battery will last about 20-24 hours probably. Currently I'm at 67% on 6 hours. Without wifi, I will get about 8-10 hours with the same kind of usage.
I just want to know why there is such a large discrepancy. Im in NYC so my signal is pretty strong.
I used to think it was the screen that used up so much of my battery life but now I'm thinking it's the radio.
I'm on Juggernaut. If anyone has a suggestion I'm all for it. Should I try a different kernel? If so, which one?
Sent from my SGH-T989 using XDA

Jugs with dark x kernel works very well with me i use faux clock to clock it at 1.7 and 384 gettin 16-17 hours of battery life with lots if texting and browsing hope it works
Sent from my SGH-T989 using xda premium

So when you use your phone, do you not expect the battery life to go down? It can't stay at 100% after everything your doing..

I recommend Juice Defender. It turns off data when your screen is off. Sounds like you're getting a lot of screen off drain.

cashyftw said:
So when you use your phone, do you not expect the battery life to go down? It can't stay at 100% after everything your doing..
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I do expect it to go down. Hence I thought it was normal until I noticed a huge difference in battery between being on 4g v. wifi and getting double the battery life while doing the same things.
I'm just wondering why the 4g takes that much more than my wifi and if a kernel would be an issue
Sent from my SGH-T989 using XDA

disturkis4u said:
I do expect it to go down. Hence I thought it was normal until I noticed a huge difference in battery between being on 4g v. wifi and getting double the battery life while doing the same things.
I'm just wondering why the 4g takes that much more than my wifi and if a kernel would be an issue
Sent from my SGH-T989 using XDA
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The simplest explanation that I can come up with is twofold.
First 4G requires a MIMO type of connection, even on T-Mobile. So for the really high speed connection it actually uses more than 1 antenna and powering more than one antenna takes up more power.
The second part is that 4G connections are not as prevalent as 3G connections so your phone has to search for the closest 4G network more often to maintain the fastest connection and the network searching takes up even more data then than the MIMO style connection the phone uses for 4G.
The combination of these two will drain your battery much faster than a single antenna connection to your home wi-fi that does not have to pass as many syn/ack packets to maintain the connection as the 4G network and thus uses less energy.
(MIMO stands for multiple in, multiple out which means it uses more than one antenna for incoming and outgoing transmissions)
(Wirless-N is MIMO based as well but does need to use as many "discovery or syn/ack packets" to maintain the connection)

I second juice defender. You can configure it to turn off data while the screen is off which will not effect your ability to receive phone calls or text messages.
Sent from my SGH-T989 using XDA

Just gotta email from sprint

They were sayn that wifi saves batt up to 50%. Ive always been told the exact oppisite. Wifi kills batt life. Wtf
Sent from my SPH-D710 using xda premium

harley1rocker said:
They were sayn that wifi saves batt up to 50%. Ive always been told the exact oppisite. Wifi kills batt life. Wtf
Sent from my SPH-D710 using xda premium
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Depends on distance/strength of wifi signal...
It's a good way for them convince you to not use your data connection for a while and slow down the network.
Sent from my Super Galaxy'd SPH-D710

I got an email/text or statement insert saying the exact same thing. Funny thing is ever since that statement I have always made sure to have wifi on when home.
I know it sorta turns off when disconnected but then it scans and picks up wifi networks so I just turn it off when I leave the house.
On my OG Evo I did not notice any change in battery life with wifi on.

Searching for WiFi is what really kills the battery which is why I turn mine off and on manually rather than leaving it on. If I'm in an area with WiFi available and my 3G signal is low, then I'll turn on my WiFi, also when I'm at work or home my WiFi is always on but if I'm out and about then I keep WiFi off rather than have it drain my battery constantly looking for signal.

Technically, I think Wifi takes up less battery than, say 3G when actively used.
Just a guess o-0

MochaCharok said:
Technically, I think Wifi takes up less battery than, say 3G when actively used.
Just a guess o-0
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I would think this is true, especially if you're sitting close to the router like at home or work rather than pinging off a cell tower however far away.

It goes both way guys. When idle, wifi consumes more battery than an active cellular data connection.
By virtue of simply being more efficient, wifi consumes "less" when actively using it. This is, however, because of the generally increased data speeds: it takes less time to accomplish a task (I.e. downloading a file), thus providing battery savings. In this regards, even 4g consumes less battery, even though it technically takes more juice to run 4g.
The way to really look at it so it becomes clear is say, hypothetically, you had a wifi connection whose internet side connection was very slow. In this regards, wifi doesn't save you any battery, and will probably end up consuming more, simply because its gain in efficiency is now gone.
Of course sprint wants us to get off cell data as much as possible, but in a lot of real world situations, it will save someone battery. Take my typical work day for example:
I wake up at home, drive to work, stay at work all day, then go home and probably stay there. I have good wifi connections both at home and work. Now, if I was the kind of user that didn't auto sync anything, I would probably end up using more battery life than I need to if I left wifi on all day, simply because I'm pumping juice into a radio that isn't being used.
However, I DO use a lot of auto sync functions, which means that my phone is actively using data a lot throughout the day. In this case, the battery drain due to the time in which wifi is left idle is out-weighed by the gain in battery life I get by the times my wifi is now being used instead a cell connection.
In a nutshell, as I said at the beginning, cellular data connection is more efficient at being idle than wifi (provided it's a good connection), and wifi is more efficient at being actively used (again, provided it's a good connection and the internet-side speed is sufficient).
Sent from my SPH-D710 using xda premium

My battery last far longer on wifi than 4g, not even close in my book.

Since I have wi-fi at work and home I can say there is a HUGE difference - especially since at home and work the 3G/4G signals are so weak that the phone burns quite a bit of battery just searching for a signal. Hoping that this will change as NV completes in the area but it might be the frequency that we're on is not too friendly with the newer building materials.

Yes, using wifi will save you more battery life than using your 3g/4g

Pastie13 said:
My battery last far longer on wifi than 4g, not even close in my book.
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4g is a completely different animal than 3g when it comes to battery drain. So far when on 4g your battery life is sucked out of your phone. The email Sprint sends out I would safely say is comparing 3g to wifi.

That same tip is on Sprints website when you log into your account. It is on the right hand side.
As for battery life my findings have been WIFI uses less juice when the signal is good. 3G uses less juice when the throughput is good. So when I am on 3G in an area that has good speeds I can hit near 30 hours of battery.
I can do the same on WIFI when the WIFI signal is good, but if the WIFI signal is on the lower end the throughput slows since the quality has been lowered.
So in essence the better the throughput the better the battery, because when the phone wakes to check on any sync items setup the longer it takes to make that check the longer the CPU is at max and the more battery drain occurs. And I'm not talking signal strength for 3G since you'll get more drain on the battery in lesser areas because the phone is naturally going to have to boost the transmitter power. I'm talking best signal and crappy 3G network throughput. That is where the drain comes from.
I have tested this in my house with my WIFI and my Airave. On WIFI if I go outside my WIFI range is really bad and my battery drains a lot quicker. If I turn off the WIFI and use the Airave, which has a much higher transmitter power, I can get great battery. I have also seen this in over night testing. My WIFI is in the living room which is 5 walls away and the signal is pretty poor. If I leave my WIFI on over night and not charge my phone I loose 50% battery and when trying to use my phone for internet I get super bad throughput since I am on the edge of the signal. But turn off my WIFI and ride on the Airave I only loose 15% over night and the internet is great, but limited to 1.5m since it is 3G. So if you download a 1meg attachment. 3G takes 2 min and WIFI take 4 min then 3G will use less battery. This also goes vis versa. Whoever is maxing the CPU the longest is your battery killer because both are always on and always ready when they are selected.
Hope I didn't go into to much detail, but transmit power is not the big thing here it is throughput quality of the signal. The worst the throughput the more time it takes to transmit and thus more battery as the CPU is maxed till the job is complete.

Hotspot for online games? Requesting advice please.

Hi! Recently my family started watching a lot of youtube in the house and in my area we only have a 1.5mbps <.< So I decided to use my phone as a hotspot to play online games. The issue is, sometimes I would get really high ping. I know in my location i can get a decent 10mbps off Tmobile's 4g but the stability is the issue here since online games constantly transfer data, even though it is very little. I was wondering if anyone knew a trick with SG2 to get a more stable / reliable connection. I searched for it and found another phone to adjust the minimal signal strength or some way to boost the 4g connection power consumption but nothing for the SG2...
I'm using juggernaut v5.0 with dark side kernel for GB.
Also when use hotspot, the battery drains extremely fast. What i've been doing is waiting for phone battery to hit 5% and then plug in the power till 100% and 10 minutes or so. But would it be better for the battery if I just leave it plugged in? this has been bugging me a lot.
Please and thanks :3

yindraad said:
Hi! Recently my family started watching a lot of youtube in the house and in my area we only have a 1.5mbps <.< So I decided to use my phone as a hotspot to play online games. The issue is, sometimes I would get really high ping. I know in my location i can get a decent 10mbps off Tmobile's 4g but the stability is the issue here since online games constantly transfer data, even though it is very little. I was wondering if anyone knew a trick with SG2 to get a more stable / reliable connection. I searched for it and found another phone to adjust the minimal signal strength or some way to boost the 4g connection power consumption but nothing for the SG2...
I'm using juggernaut v5.0 with dark side kernel for GB.
Also when use hotspot, the battery drains extremely fast. What i've been doing is waiting for phone battery to hit 5% and then plug in the power till 100% and 10 minutes or so. But would it be better for the battery if I just leave it plugged in? this has been bugging me a lot.
Please and thanks :3
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Idk about anything to boost the signal but I definitely would advise you to not leave your phone plugged in while you play nor leave it plugged in after its fully charged.
Sent from a Galaxy 3759295 light years away.
Thank me if I helped

http://forum.xda-developers.com/showthread.php?t=1661286&page=2
You can try to get a signal booster from Tmobile, supposedly its free but they restart your contract ($500 retail).