The Truth About Your BatteryGeneral

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  1. hbryder

    hbryder Well-Known Member

    So if you are connect to a network via wifi you are saying that it still searches for other wifi signals. That seems odd to me. I could understand if you had wifi on but weren't connected yet?

    TheClammer likes this.
  2. SUroot

    SUroot Well-Known Member Developer

    Its the latter, wifi + connected is best for power as mobile data is not being used but wifi without connection will keep scanning for networks.

    With Wifi Connected:

    Wifi 1 + Mobile Data 0


    Wifi Disconnected:

    wifi 1 + Mobile Data 1
  3. Easilyamused

    Easilyamused Well-Known Member

    That's not true. Both the BT and the Wi-Fi radios are passive; they only listen to the network and take almost no battery power (If Bluetooth was the only thing drawing power from your cell phone battery, in this passive mode your battery would go years on a single charge).

    Since both are very short range (BT more so than Wi-Fi obviously) even when connections are established and they both send and receive signals, their power consumption is designed to be minimal.

    Turn on the hotspot feature and the Wi-Fi - on top of sending and receiving packets - becomes a constant transmitter and will use significantly more power.
    hbryder and KOLIO like this.
  4. Heisenberg123

    Heisenberg123 Well-Known Member

    are these stats realativley normal?

    Im not 100% sure how to interprut the Radio usage screenshot


  5. SUroot

    SUroot Well-Known Member Developer

    I am not so sure that the WiFi is passive. I also strongly believe that disconnected WiFi drain is not negligible. Sure its not quite as much as when its connected but it is significant, particularly when connected to mobile data.

    I can see my WiFi (When disconnected) doing an active scan, every 5 seconds. Literally, if I go into WiFi settings - I will see the scanning icon and the word "Scanning" appear every 5 seconds. This is actually fairly typical of 802.11

    Also, I have decompiled the frameworks and have identified the following boolean:

    Code (Text):
    1. <bool name="config_wifi_background_scan_support">false</bool>
    I am not sure if this refers specifically to passive activity, but a description for this bool is here:
    (citation from another source repository - )

    So my belief is that the chipset doesn't fully support passive scanning and is actively scanning every 5 seconds for networks to connect to.

    With this in mind, I would also like to bring to the forefront, how Samsung estimates power usage

    Code (Text):
    2. <item name="">17</item>
    3. <item name="bluetooth.on">0.3</item>
    Well that definitely agrees what you say on BT as there is the entirety of it's power consumption values.

    But for WiFi

    Code (Text):
    2. <item name="wifi.on">0.3</item>
    3. <item name="">96</item>
    4. <item name="wifi.scan">70</item>
    So here we see 96 when connected, 0.3 when on but 70 when scanning (which my device does every 5 seconds). So yes I agree that it does not use as much power as when connected but I think this is significant none the less.

    Where did the passive idea come from? Is it published in some technical specification document?
  6. Easilyamused

    Easilyamused Well-Known Member

    Yikes! I am almost intimidated by your post. :)

    Very interesting stuff tho...

    In response to your first question, many years of experience, schooling, and reading technical documents/diagrams, albeit not necessarily about cellphones or programming.

    In answer to your second question, probably.

    Without getting into a lengthy (which I have no problem doing as this is very interesting to me, but I must be somewhere in 30 min.) discussion, I am going to make an assumption or two.

    WAPs (Wireless Access Points) transmits beacons several times per second. It is active in that it transmits beacons (or signals) announcing its existence. I am going to assume you and I agree on this.

    In general, wireless clients are passive - I use that term in that they "listen" for those beacons transmitted by WAPs. As these beacons are transmitted several times per second, when a wireless client enters their range they seemingly appear "instantly". I would also assume we agree on this.

    Now in my statements regarding battery usage on the GS3, I have taken for granted - perhaps erroneously, but I would have a hard time believing that - Wi-Fi radios in the GS3 and smartphones in general also work under this premise.

    On the other side of things, I would use the term "active" to describe a scan which transmits or "probes", seeking out whatever (in the context of this discussion, that would be WAPs).

    Now, stating that, I have taken a bit of liberty here in that I don't have a technical document that states this is how the radio in a GS3 (or in general, any smartphone) works. To me, it wasn't even a thought... Why would anyone design a radio in a device that needs to conserve as much power is possible that actually consumes power by actively probing for devices that they don't need to seek because they announce themselves?

    Finally, and this is where it gets really interesting for me due to some things you stated in your post... using monitoring software to measure usage over significant periods of time, power consumption was no different in areas where I was connected to a WAP and areas where many existed, but none which I were connected to. The only difference in usage was when transmitting large amounts of data while connected to a WAP, usage increased over when I was not connected, or connected but not transmitting much data.

    Anyway, have to run.. but I am curious about the coding you brought up... is everything shown on battery software based on the values as shown in your code examples? If so, given they are based on estimated values, doesn't it make the software rather inaccurate?
  7. aquadog

    aquadog New Member

    I have the exact same problem as you. 100% battery before sleep, 10% when I wake up. GPS, bluetooth, sync off, wifi, mobile data on.

    I have to recharge the phone at least twice during the day, every day. This is annoying when I don't have a charger with me. Last week it died at 3pm and I had to use a payphone...something I haven't done for over 10 years! This is a huge problem and has almost rendered the phone useless.
  8. SUroot

    SUroot Well-Known Member Developer

    Yeah I think we need to investigate further. I'm not saying either way is fact at this point. Just that I am not sure. The only thing I can say for definite is that my wifi settings page appears to be scanning every 5 secs. Scan 3, wait 5

    Please don't be intimidated by my post. It's just information at this point :)

    One further thing though, its possible a phone being the most portable that it works more actively to find a wap, given its usually in the pocket.

    The values in power_profile.xml are estimates. These are used by the battery stats page. This is the file that caused the massive appearing cell standby "drain" so 1) yep its inaccurate as they are only estimates and don't take account if signal strength and 2) samsung already made one mistake in this file ;)

    Other battery apps break usage down much further than this file though so they can't be using it. They must be using draw to calculate.

    My favourite was current widget. It logged mA for me at an interval of my choice (30 seconds) so I could historically see my draw. Unfortunately this doesn't support the s3 at this time.

    I think next I shall look into the kernel source and see what I can see.

    Yep its an interesting topic. Looking forward to getting to the bottom of it all.

    On my desire, I definitely noticed a difference between wifi disconnected and wifi off. But as thats a software thing its extremely likely to differ between oems. I haven't tested on the s3 as tasker turns off wifi anyway
  9. Malevolent123

    Malevolent123 New Member


    I have an external battery that i have been using with my old phone for about a year now, and decided to get a galaxy S3. I understand that the galaxy charger ouputs at 1000 mA but the max current output of the battery is 700mA. I have already tried using it to charge the phone but it took about twice as long as it does from the charger. Will using this battery with the S3 damage the phone, its battery life or have any negative side effects?

  10. dbpaddler

    dbpaddler Well-Known Member

    Nope. It'll just be slow.

    I'm a heavy user and work in some signal challeneged areas. I've even brought an iphone 4s in and showed me burning through its battery in under fiver hours just to shut up the fanboys at work. I'm more of a fan of spare batteries. I keep one charged in the car and one charged at home. Those little universal chargers that charge via microUSB are nice. And you're always going back to 100% after a swap instead of dealing with charging and being tethered.

    Granted, there might be internal things going on via bad programming, rogue apps or what not, but also using an Epic (on Sprint) I do notice better battery life with slightly stronger signals in areas where I had less, or it hands off to roaming more efficiently. Still wouldn't mind seeing larger quality stock fitting batteries. It's a shame the third party ones never live up to their size claims and if they can make slightly physically larger batteries that fit with the stock back, why couldn't sammy stuff a larger quality stock battery in there? Everybody wants us to do more on our phones and everybody wants us to stream more and go to the cloud. Well this shit requires juice and nobody wants to do the one thing in light of more efficient processing, screens and other tech; and that's give us the biggest f*cking battery they can possibly squeeze in, even if it's at a slight thickness or size compromise. Sammy at least kinda gets it over Moto and HTC with their embedded silliness. Though Sammy really screwed the pooch with the Mini 3 IMHO.
  11. Easilyamused

    Easilyamused Well-Known Member

    Look through this thread and read the responses to blenkows posts. Try them and see what the results are. Unfortunately, he hasn't responded since the last suggestion... perhaps you can continue instead and follow it through?
  12. rushmore

    rushmore Well-Known Member

    The battery drain with the GS3 in weak 3G areas is worse than my previous devices, but is better than them all with good signal.
    Bipolar it be. Previous 3G devices: Droid 1, Incredible, DX2, Droid 3 and Razr.
  13. dbpaddler

    dbpaddler Well-Known Member

    Hero, Moment, Evo, Epic, Photon, Photon Q, S3. All suck in signal challenged areas and drain quickly, no less no more than the S3. All on Sprint mind you.
  14. blenkows

    blenkows Active Member

    Even if it was just reporting it wrong, that doesn't change the fact that my battery was drained. When I sorted by "total time held awake", it was only like 2 minutes. Something MUST be causing it to stay awake that isn't getting reported or something...

    And it was strange. I took out my battery, put it back in, and the problem appeared to go away for a few days. This is why I stopped posting lol. Well.... it's back as of last night.

    And I don't really wanna mess with the software and all that. I'd rather just know WHY this is happening is all.
  15. _GalaxyS3

    _GalaxyS3 Member

    what a crazy convo
    I enjoyed this thread very much
    Thank you all, specially Easilyamused
  16. SUroot

    SUroot Well-Known Member Developer

    This is the best thread in this forum. All battery threads should be merged into it :)
  17. rborelli

    rborelli Well-Known Member

    I found GSam Battery Monitor. Is this the one you use? It looks pretty good.

  18. Wisenos

    Wisenos Well-Known Member

  19. dbpaddler

    dbpaddler Well-Known Member

    I just bought Roam Control, and in two places where my battery would just drain trying to maintain the Sprint signal, I now force roam on Verizon and maintain around 3 bars with much less battery drain. Next Tuesday should be a long day at the one place so I'll see how that works.

    They really should address situations like that. There has to be a point when the phone has to stop struggling to maintain the home network connection and force into roaming. Let it go check every 10 minutes or so for a solid home signal, and if it's not there, keep it roaming.
  20. seagood3

    seagood3 Member

    Thanks for all the great info - very good thread.

    I could use a little help with my phone. Battery life is starting to really go downhill. I am generally a light user. I don't have too many apps and try to turn off syncing on most of them aside from gmail. I got a full charge before bed last night and woke up at about 68%. Not awful, but definitely not good. Any help would be greatly appreciated.



    Edit: Images don't seem to be working. Here are external links
  21. KOLIO

    KOLIO Guides Guide

    Yeah, that's the one I was referring to (sorry for the TYPO) ;), gonna travel back in time & fix this now. :p
  22. dbpaddler

    dbpaddler Well-Known Member

    Not a solution but a curious question. Why would you not charge the phone overnight so you wake up with a fully charged phone to start the day? Seems like a basic thing to do.
  23. Easilyamused

    Easilyamused Well-Known Member

    Try turning mobile data off before you go to bed and see how that affects it. One of the things I think we overlook is the reporting issue with the radios. Sure, it's not reported correctly, but that doesn't mean we can rule the radio out all together.

    Unless I'm missing something everything else looks pretty normal.
  24. dportal2006

    dportal2006 Well-Known Member

    It should turn everything off. If you received text messages then airplane mode was not on.
  25. seagood3

    seagood3 Member

    I do generally charge my phone at night, but I was noticing my phone performance was down during the day so I wanted to see how would perform overnight with no use.

    I will give the mobile data a try tonight. Would you agree that that is a bit of a heavy drain overnight with no obvious battery hogs?

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