yashsingh1/xdaforums huggingface dataset:
[Galaxy S II Q&A, Help & Troubleshooting] xinfinityoO:
u do understand that.. the only router/wifi u can modify is ur own .. :rolleyes:

and i bet many of us use wifi out of home..free ones etc and even at work.. coperate organisations..i dont think they will modify their settings just for your mobile

yeah if ur just using ur home wifi then play around with the channels.. btw 2.3.4 update has a new option under advanced settings.. u can select the range of channels the mobile will use :)
[Galaxy S II Q&A, Help & Troubleshooting] JFSG:
Couldn't figure out how to do this with my router. This problems occurs for me even when I'm just right in front of my router :(
[Galaxy S II Q&A, Help & Troubleshooting] JFSG:
This issue is history since installing the latest version of Lite'ning ROM! :)

*Don't forget to set your Wifi sleep policy to never.
[Galaxy S II Q&A, Help & Troubleshooting] Athavan:
same problem

Im having the same problem...when wifi is turned on it scans fro network and detects nothing... it worked superfine fro more than 2 months.. im encountering this problem for three days.. tried fw upgrade,factory reset,etc... no use..

any suggestions frnds??:confused:
[Galaxy S II Q&A, Help & Troubleshooting] JFSG:
Root + Latest Lite'Ning ROM. :D
[Galaxy S II Q&A, Help & Troubleshooting] juanitolol:
Best answer. this works for me.
[Galaxy S II Q&A, Help & Troubleshooting] rammkp:
Wifi problem fixed

Hi All

I had this problem for couple of months. Wifi connects but data transfer does not happen. Tried different modems/kernels/roms etc. Nothing seemed to work. In the end the problem was to do with Wifi mode in the router.

I have a Netgear DGN1000 router and Wifi mode was set to "Upto 150 MBps". I remember changing that when I bought a new personal laptop. I changed the mode back to "g&b" and voila, wifi in SGS2 started working fine.

Regards

Ram
[Galaxy S II Q&A, Help & Troubleshooting] PacStealer:
hi guys, i have the same problem in my 2.3.6 sgs2

randomly it loses wifi connection(but wifi icon still there and ok)... after some tries it restart the connection but when i for ex play zyngapoker i had to get out from the app...

i had the same problem on my iphone 2g... what now? do i have to use only one radio channel in my router?
[Streak 5 Q&A, Help & Troubleshooting] jm5503:
Where's the best and quickest site to get an unlock code for my AT&T Streak??? I wanna use it with T-Mobile .......
[Streak 5 Q&A, Help & Troubleshooting] Dsmwookie:
http://xdaforums.com/showthread.php?t=697462

Search.
[Streak 5 Q&A, Help & Troubleshooting] marvin02:
If you have been an AT&T customer for a while (I believe 90 days is enough) call them and ask.
[Streak 5 Q&A, Help & Troubleshooting] jm5503:
I haven't.....I'm a sprint customer who really wants a streak w/ T-Mobile.....I'm buying one today but it's locked to at&t.....anyone know a good quick website???
[Streak 5 Q&A, Help & Troubleshooting] marvin02:
try this?

I have not used it.
[Streak 5 Q&A, Help & Troubleshooting] Dsmwookie:
You do know the ATT version will not get 3G signal right?
[Streak 5 Q&A, Help & Troubleshooting] jm5503:
Yes I know
[Streak 5 Q&A, Help & Troubleshooting] Dsmwookie:
Have you considered a Cincy Bell version?
[Streak 5 Q&A, Help & Troubleshooting] Alahdal:
Since you are ATT customer try this: http://xdaforums.com/showthread.php?t=1153449

It worked for me.
[Galaxy 3 General] Mohit12:
Thank you for it, but your "this" does not link to any thread. However, I'm assuming you mean for it to be the link that the "here" for the 'ultimate android app' links to. Might want to change that. Thanks for the tips, though.
[Galaxy 3 General] neo1691:
Thanks a lot for that!! Fixed the link!!

Yes its the ultimate app!! :D
[Galaxy 3 General] rudolf895:
Idk why keep higher minimum CPU frequency your battery should have drained faster even when your phone would be idle..

For me this worked :

*Not using set CPU for short time profiles.(not using different frequency while phone is on standby)

*Exiting apps using the back key, home key put the apps to background task.

*using 2g when needed..

*use wifi for bigger than 10mb download as it woudl be fast n easy.

*least brightness

Hope this helps some one. ;-)

Tapatalked from my super smooth, ultra fast samsung galaxy s2.
[Galaxy 3 General] ka'cipeder:
this doesn't make sense, if you set governor to performance your phone will be running at 1366 mhz at all times regardless of minimum frequency and that will murder your battery. Make a profile for screen off and set it to 83 or166min and 222 or 333 max and ondemand governor, that will save you some battery. When you use the phone set the max frequency to 667 or 800 with conservative or ondemand. Use high freq only when needed - for playing heavy games
[Galaxy 3 General] neo1691:
I was excepting this post from someone.. Yes you might say why keep governor to performance with 1366 max.. well thats how we tackle lag!!! :D

@rudolf!

Surprisingly battery drain is very less for me (and some others too) with these tweaks.. otherwise why would i share them!! :P
[Galaxy 3 General] rai_tushar:
1 more solution:-gallery 3d uses more battery

u can use quickpic as a replacement
[Galaxy 3 General] neo1691:
exactly.. Thank you. will update the op as soon as I find a laptop., I always use quick pic but never really considered it a battery saver..
[Galaxy 3 General] ron_gangte:
Disabling SNS is also a good way to save battery.

Not applying the RAM optimization script provided in the Dev section will also save battery 'cus I have faced increased battery drain with it.

And does reducing the voltage save battery? If so.. can you please provide some info about it..??

Enviado desde mi Galaxy 3
[Galaxy 3 General] danveer:
thanks for the info as i was just about to install the ram optimization tool but considering that it sucks more battery, i wont do it
[Galaxy 3 General] neo1691:
Try the above . Of that still don't help you, then you are can try ram optimization
[Galaxy 3 General] kyrillos13:
"-Flash Fugumod ultra kernal (this worked for me, havent tried G3mod kernals)<link>

Flash this kernal and use set minimum frequency for 780 hz and Maximum frequency to 1366 hz.

Set the governor to Performance"

with this, the battery will last a full day maximum (with normal-low usage)!
[Galaxy 3 General] neo1691:
agreed.. theoretically it should last not more than one day!! but seriously i have tried that and my phone practically lasts for more than 35 hours..

And that's y i am sharing the info!!

EDIT: setcpu v 2.1.3
[Galaxy 3 General] nrk_2k:
Reducing the voltage to the CPU may cause problems and will not save any battery. You can think of it like a simple circuit, with the CPU effective being a "resistor". so you have just a battery, voltage regulator, and CPU, as you reduce voltage, amperage will increase (and battery drain will actually increase!!!) Amperage is what drains your battery, not voltage.

My recommendations (I have tertiary electrical engineer qualifications to back me up)

- Stick with the stock voltages for the different frequencies you use.

- To save battery, turn off wifi & bluetooth when you are not using them.

- Install APNDroid, to easily switch 3G/EDGE data off when not needed (still allows you to receive MMS messages when data is off, and has a widget)

- Set your screen to the minimum brightness that you can (but so that the display is still bright enough to use)

- Turn of "Power Saving" in display settings (actually uses more power than it saves 9 times out of 10)

- Use task manager, or a ram management tool to kill apps that don't need to be running in the background, and always use the back button to go out of apps, the home button will leave the app running in the background (sucking battery and slowing the phone down)

- If using a CPU management tool set minimum to 83MHz (or lowest your phone is happy with, or that you are happy with to kill lag), set maximum to whatever you like (that phone can handle) and use a governor like "on demand". Set up profiles to lower maximum frequency when screen is off, or temp is high (higher temperatures will result in faster discharge off battery)

I do all of this, and I can get up to 3 days use without charging (depending on usage)

Things that will drain your battery the most (highest power usage):

- Wifi

- Bluetooth

- 3G/EDGE

- Screen

- Phone calls
[Galaxy 3 General] sharukins:
sry, but this is completely wrong.

if it was true what you said increasing the voltage would save power...

decreasing the voltage DOES save power, but unless the CPU isn't running at maximum load the whole time you won't see a big difference.

the frequency of the CPU raises the consumed wattage linearly while voltage goes into the calculation by square. so decreasing the voltage is the best option to lower the consumed power of the CPU as the speed isn't affected. problem is of course that the CPU won't run below a certain limit. the CPU in my G3 is running 800MHz @ 1.125V which is 75mV below stock (667MHz).

the amperage does not change while undervolting.
[Galaxy 3 General] nrk_2k:
First off, I never said anything about saving power, as power is the resulting work of voltage vs. amps, I was talking about battery drain, not power (they are totally different things). The voltage of a battery will not change greatly until it is nearly empty (if it did, it would be pointless rating a battery to a certain voltage), where as the amperage will lower as the battery gets drained. The amount of time a battery lasts is determined by its amperage, not voltage (hence why a 2100mAh battery will last longer, doing the same amount of work as an 1800mAh battery). So if what you claim (amperage not changing while undervolting) were true, then you would see NO change in battery drain due to undervolting. Voltage NEVER drains a battery, it's the amount of amps being drawn that drain the battery. P=IV is the power equation for a closed DC circuit. If we assume P is a constant (which it has to be, to be getting the same output from a CPU) then when you lower V, I must therefore increase. and Likewise, if you raise V, I will decrease.
[Galaxy 3 General] neo1691:
well i am having just perfect battery without undervoltage..!! :

but ya definitely learned many new things from the above discussions
[Galaxy 3 General] sharukins:
I didn't want to start a discussion about this...

the wattage isn't constant as you calculate it.

calculation power is not equal to electrical power.

voltage itself of course does not drain battery, but what drains battery is wattage, and wattage is reduced due to lower voltage.

the problem is that the unit mAh isn't really the capacity of the battery. the right unit would be Wh or mWh.

so you have to multiply the mAh with the voltage of the batter to get the real capacity.

so decreasing voltage in fact does save you some battery life, but as I said, you wouldn't notice it unless the CPU is under full load the whole time as in smartphones biggest power consumption comes from display and other parts (at least with the slow CPU in the G3).
[Galaxy 3 General] neo1691:
now thats what i call some serious battery saver
[Galaxy 3 General] nrk_2k:
Would have to disagree about a true measure of battery capacity being the Wh, or mWh, as wattage depends on load, and since you never run a battery with 0 load, you cannot represent its capacity using Wh or mWh. I have studied batteries intimately at university level, and know exactly how & why they work. the mAh (Ah) is the industry wide accepted unit for battery capacity, as no matter what the load it is always constant. I am happy to agree that wattage is not always constant for a set frequency on a CPU (as it is possible to over-voltage for that frequency), but for processors such as those which are used in our phones, you very rarely find any substantial over-voltage as due to modern manufacturing techniques there is a much tighter range of voltage acceptance for the core. Hence why most people get only a minute (completely stable) undervoltage. And anyone who would actually gain from undervoltage, would be able to tell that their CPU is using excess energy as ALL this energy would be dispersed as heat. Any extra wattage drawn over what is actually required by the components inside the CPU will be converted to heat as it is not required by the components to run. So unless you see excess heat from your CPU, undervolting will only achieve degraded performance, or CPU stalls. And it is at this point that it will drain the battery more, as there is a minimum wattage that a set frequency requires, if you drop the voltage below what it should be, the amperage will increase to mantain the minimum wattage required (or the CPU will stall and the phone will freeze/switch off). The only real world point to undervolting a CPU is for cooling purposes, the energy savings from doing so are minuscule, to none, and can to a point end up consuming more battery. You would save far more battery by lowering your screen brightness by a few percent.
[Galaxy 3 General] sharukins:
I disagree on the mAh unit being constant. cause it changes when the voltage of the battery is changed.

a battery that has 1600mAh with let's say 12V is far better than one with 2000mAh running on 8V.

why? cause the first one has more Wh :>

the amperage tells you nothing about real power consumption.

undervoltage does not effect CPU performance unless the CPU is undervolted too far so that not all transistors are able to switch anymore.

that's why CPU has a minimum voltage but not a minimum wattage. (it results somewhat in a minimum wattage, but it is not running at this minimum at stock specs)

anyway the point is that everey watt you save on heat coming from the CPU is a watt that is not drawn from battery.
[Galaxy 3 General] neo1691:
again something new learned..!! :D

okay if u can speak in non technical and simple language then i may be able to understand more better :D
[Galaxy 3 General] nrk_2k:
I would normally be more than happy to to explain battery fundamentals in a basic non technical way, but unfortunately I just don't have the spare time at the moment to type it all out (as I have a new born baby) but if you are keen to have a read up about it, maybe google might be able to turn up something for you to read. I would recommend reading up on electrical fundamentals first, like the relationship between volts, amps, and resistance in a basic DC circuit, and try and learn some of the basics there, and it will make it easier to understand how batteries work :D It really is quite interesting, and even though sometimes things don't seem to make sense, when you get to learn a bit more it will all fall into place :D The study I did at university was mainly computer electronics (we got to build our own 8bit CPUs) and then I studied Electrical Engineering at a tech (which is where I learnt all about batteries, AC/DC power, multiphase power, power generation, harmonics & resonance, and much more. If you are really interested in it perhaps check out your local tech/schools and see if they do night courses or learning at home :D or even just get some books from your local library and have fun reading up!!
[Galaxy 3 General] neo1691:
Heyy.. Congrats man.. Give my love to your new born child..feel Special.. :)
[Galaxy 3 General] sharukins:
so under the circumstance that our curcuit is fitted to the voltage of our hypthetical batteries with the same mAh the battery with the higher voltage will last longer, we're both of the same oppinion here aren't we?

I don't get why the amperagehour should be constant while the wattagehour is changing as you are able to convert voltage and amperage outside the battery and with this Wattage is constant while voltage and amperage change.
[Galaxy 3 General] sharukins:
sry just tried to understand with my sixth grade knowledge of electric physics.

if you had explained it with an galvanian cell where the amount of molekules which can react is finite and therefore the electrons which can move are finite.

I hadn't thought of that being absolutely incremental for DC voltage. (as it is not for AC voltage)

sry for that, I'm looking more at the chemical side of life :D

but thank you, now I think I understood it.
[Galaxy 3 General] rudolf895:
why would some one rate this thread 2 stars?

Seriously! Lame trolls!

I'm rating it 5 stars to balance it
[Galaxy 3 General] neo1691:
What two stars?? Lol.

Well I am going to quote important posts given by some knowledgeable people in the OP
[Galaxy 3 General] V!KR@M:
ur signature says oc 1377 Mhz. I thnk it is 1366
[Galaxy 3 General] V!KR@M:
I hav a small doubt. U said to consider a simple ckt consisting of cpu as effective resistor, battery and voltage regulator. U said I increases if V decreases. But as per ohm's law(V is directly proportional to I), I must decrease if V decreases.

Plz correct me if im wrong
[Galaxy 3 General] neo1691:
i think its time to change the signature!!
[Galaxy 3 General] jibeesh619:
My samsung galaxy 3 battery just drains like hell...

It gets charged to 100% fast (when plugged in, charging starts at about 80% level )

Then it becomes 100% in about 5 minutes

Then in about 30 minutes it switches off

It also turns off if i use data connection for about one or two minutes.

Is my battery permanently damaged ??? ( i used to browse and download alot while charging )

or is it just calibration issue ???
[Galaxy 3 General] neo1691:
no ur battery isnt damaged..!!

you have to calibrate properly!! :D
[Galaxy 3 General] sharukins:
voltage is indirect proportional to amperage as P=I*U

so if P is constant I will increase if V is lowered
[Galaxy 3 General] V!KR@M:
ok i understand. The power that is to b delivered at cpu must b constant. So to compensate it, the "I" increases
[Galaxy 3 General] sharukins:
I still don't understand it completely but this is the basic thougth behind it.

I hope someone can still explain me why undervolting saves power at my desktop CPU as it consumes DC voltage as well and the wattage decreases...
[Galaxy 3 General] nrk_2k:
Hey guys, I'll try explain the CPU thing a little better if I can, as it has more to it than just electrical dynamics. Basically, a CPU has a fixed resistance for each electrical component contained in it. As power is supllied to it, it heats up, increasing the internal resistance of the CPU, and therefore decreasing the current flowing through it. And we can calculate the power from the known voltage and current. Now, at a lower voltage, less heating occurs, which means lower resistance which means higher current. Which is why I presumed power consumption as being a constant for a set frequency. This only works in a passive cooling example, like a phone. In your computer, you have an active cooling system (it has a fan) meaning its cooling is more efficient, and undervolting has a more practical effect, other things such as the PC getting its internal power from an AC source, that is converted to DC also have an effect as DC power of this form is not pure DC, but has a very slight oscillation to it.

Sorry if I was a little too technical in some of my posts, its hard to dull down the complexities of electrical engineering, but still retain the full detail required to make it make sense :-) that and I wrote most of my posts while tired or at work, so a little distracted and probably contradicted myself a little, making it harder to understand lol. And yet again I'm posting while tired lol. :-D
[Galaxy 3 General] sharukins:
but as we are talking about CPU which is a semiconductor it should conduct better when heated, as more electrons can jump over the band gap into the conduction band.

which means that a cooler CPU should consume at least a little bit less amperage.
[Galaxy 3 General] V!KR@M:
@nrk_2k, i thnk u hv created a bit more confusion. Why wud the internal resistance of cpu wil increase or decrease with the power :confused:

Hw cn the internal resistance increase or decrease? Is it a variable resistance?
[Galaxy 3 General] sharukins:
he said that resistance changes with the temperature, not with the power used.

the resistance of electrical metallic conductors always increases with higher temperature.

higher temperature means that the cores move more and faster and so more electrons are scattered because they collide with the cores.

but with semiconductors like silicon in CPU it's different. they have a high resistance at low temperatures while theiry conductivity rises with higher temperature until a certain point. from there, further heating will decrease conductivity as like it was a metallic conductor.
[Galaxy 3 General] V!KR@M:
ok i understood. Sorry for misreading the post
[Galaxy 3 General] neversaynever:
Cool, thanks for the info.
[Galaxy 3 General] rajat565:
help me

my battery is lasting only for 3-4 hours when the edge is on,its like going 1% a minute

i have tried different rom but the result is same

i thought some app might be misbehaving but the same thing is happening on a clean rom also

however when i use wifi the battery drains normally

i have tried indroid 4.3, kryillos 5.7 and the stock rom also,but the same thing is happening.
[Galaxy 3 General] neo1691:
did u flashed the ultra kernal??? or try flashing g3 kernals... do the steps in the OP!! you should get a good backup!!
[Galaxy 3 General] nrk_2k:
Yes, the CPU is made of a semiconductor material, but the material is silicon, which has extremely good thermal properties, which means the temperature range through which it is heated during operation has no real effect on internal resistances of the semiconductor components, the resistance change however comes from the tiny copper wires linking the components inside the CPU together. :-D

After a bit of thinking about the make up of the CPU, there may be a voltage range in which you could achieve lower temperatures, and save on some battery consumption, but it would all depend on the properties of the semiconductor components in the CPU. As different types have different response graphs, if I could get my hands on voltage/resistance graphs for the CPU in our phones, I could see if this is possible in our CPUs, but even if it is possible, it could be a very fine line between stability/instability.

What would be even better is if they could perfect the next-gen techs for CPUs and we could enjoy huge computational speeds with very low battery consumption. A couple I have been following are fibreoptic CPUs, and organic CPUs. Have a google for them if you want, make for very interesting reads :D I've also heard rumours of people trying to make a superconductor that works at room temperature for hopes that it could be used in CPUs. :-D
[Galaxy 3 General] sharukins:
you mean the copper connections to the mainboard do you? as CPUs are completely made of one substrate (mostly silicon).

as for high temperature superconductors I have to destroy your hopes. chemists and physicists have been trying to get one that works at room temperature for about 30 years und still we're stuck with superconductors which work at around 130°K which is as you might know about -240°C.

at least they can be cooled with liquid nitrogen which is widely available and relatively cheap.

we already have better materials for CPU like Galliumarsenic or even Graphene, but the problem is that we can't produce them in mass or they are just not cheap enough for broad use.