Wednesday, November 20, 2013

Android Devices & Battery Life - Duel to the Death




WIFI Home Network

WIFI Networks - 


Wireless networks operate using radio frequency (RF) technology, a frequency within the electromagnetic spectrum associated with radio wave propagation. When an RF current is supplied to an antenna, an electromagnetic field is created that then is able to propagate through space.

The cornerstone of a wireless network is a device known as an access point (AP). The primary job of an access point is to broadcast a wireless signal that computers can detect and "tune" into. Since wireless networks are usually connected to wired ones, an access point also often serves as a link to the resources available on the a wired network, such as an Internet connection.

In order to connect to an access point and join a wireless network, computers, smart phones etc, must be equipped with wireless network adapters. These are often built right into the device whether it be a computer, mobile phone or a  tablet. 

DHCP - 

Short for Dynamic Host Configuration Protocol, a protocol for assigning dynamic IP addresses to devices on a network. With dynamic addressing, a device can have a different IP address every time it connects to the network. In some systems, the device's IP address can even change while it is still connected. DHCP also supports a mix of static and dynamic IP addresses.

Dynamic addressing simplifies network administration because the software keeps track of IP addresses rather than requiring an administrator to manage the task. This means that a new computer can be added to a network without the hassle of manually assigning it a unique IP address. Many ISPs use dynamic IP addressing for dial-up users.

TCP - 

Short for Transmission Control Protocol. where Connections must be properly established in a multi-step handshake process (connection establishment) before entering the data transfer phase. After data transmission is completed, the connection termination closes established virtual circuits and releases all allocated resources.

Unification of these principles - 

  • If one were to bridge these three technologies together with a screen & dial pad, it would become a   " wireless access device " or smart phone/tablet.
  • Therefore, a smart phone/tablet, would have to go through the following steps each & every time it needs to make a " wireless connection " to the Internet.                         Turn on wifi antenna > scan for an access point > authentication between  access point/ wifi access device >  request an IP > bind to that IP >  establish a IP connection between AP & host > data transmission > termination of TCP connection > Turn off wifi antenna > return to stand by mode. 
  • Power is required for all of the above steps, which drains smart phone battery, each & every time a wifi connection is made. 
  • If a device is in " sleep mode " with no wifi data transmission , wifi antenna should not be drawing in power. 

 Before 

23:41 - 02:05 17- 18 Nov 2013


Galaxy Note 1 -  2 days max use
  • Notice at 23:41 battery level reading = 93 %. At 02:05 battery level reading = 77 %. Therefore battery dropped by 16 % in 2.5 hours. In both cases, phone was in " airplane mode " & wifi turned off. Yet colossal battery drain in stand by. [  If WIFI is enabled & the user selects " airplane mode " via desktop widget or by going to " Settings/ More settings / ", WIFI is disabled, but, can be enabled by  pulling down the menu [ i forget the name for it at the moment ] in home screen. Then, even though you are in " airplane mode ", you can use WIFI in offline mode ]

    After 


    01:31 - 09:16 20 Nov 2013

    09:16 - 13:27 20 Nov 2013


    Galaxy Note 1 - 13 days max use


    • Notice at 01:31 battery level reading = 58 %. At 13:27 battery level reading = 43 %. Therefore battery dropped by 15 % in 12 hours. In both cases, phone was in " airplane mode" & wifi turned off. Whoa !!! hold it right there you ask, How can this be ? before i answer that, i like to point out, above are some of the actual screen shots of battery statistics collected in real time

    These tweaks can be done on either rooted/ non rooted android phone/ tablets

    Automatic display brightness adjustment

    Settings/ WIFI/ Advanced


    1. Go to Settings/ WIFI/ Advanced/ - Disable ( uncheck ) " Network Notifications " [ Network Notification = as most know, WIFI scans for Access Points/ Routers at pre determined times. Which uses up battery power nevertheless. So if you have pre configured WIFI access points, eg { home/office } WIFI networks, there is no need for it be pulsing so many seconds to see if there is a WIFI AP by that name. " Network Notifications has nothing to do with incoming sms/ email/ chat alerts,  all it does is, let the user know if a WIFI AP/ hotspot is nearby ]. " Keep WIFI on during sleep " = NEVER [ Increases data usage ]. Default settings for " Keep WIFI on during sleep " = ALWAYS = Faster battery drain.
    2. I need to explain what the above sentence means because, it was staring right in my face but i overlooked it. " Keep WIFI on during sleep = Always " means, in simple english, DONT turn off WIFI even when in stand by mode. WIFI is just like any antenna, draining power whether you use it or not. So, " why is a WIFI antenna continue to supply with power " when its not being used ? doesnt make any sense to keep it at default = faster battery drain. Now this is the funny part, okay, you might ask yourself, it has to be a firmware bug. But, in truth, this " default " setting has been " in effect " from the very first android device made. Now, comes the more interesting quirk to it, this tweak varies from phone/ tablet to phone/ tablet. These settings even though you change it to " Never " defaults back to  " Always " for some devices, even with latest android firmware. I was lucky with 3 android devices, where this tweak didnt default back to " Always ". Therefore, id say, try it and see, you might need to re check the " Advanced "settings to verify that fact. Do this test on a full battery charge. So why does it say " Never = Increases data usage " ? that i suspect, was added there, to fool the user into selecting  " Always " option. I did note down, data usage counters for both WIFI/ 3.75G at 01:31 and at 13:27, to my utter shock, there was zero data usage during that time period. Screenshots of battery usage during that 12 hour period speaks volumes in itself. 
    3. Location Services ] - " Disable " ( uncheck ) Use wireless networks/ Use GPS satellites/ Location & google search.  [ enable/ disable them when & you require their functionality. ] 
    4. Shutdown/ Restart the smartphone/ tablet once every 3 days is another good practice.
    5. Similar tweak can be done to 3.5G/ 3.75G/ 4G [ Settings/ More settings/ Mobile Networks/ Network Mode = GSM/WCDMA/ GSM ONLY/ WCDMA ONLY ]. Voice calls always use 2G bandwidth even though 3.75G/ 4G is enabled on the smartphone/ tablet. Therefore, that " extra  " 1.75G is just draining the battery faster. I would recommend, disabling 3.75G/ 4G during a voice calls and enabling 3.75G/4G only when its necessary. This rule doesnt apply if one were to initiate a video call where 3.75G/4G " has " to be used for that task. If service provider permits, enable 2.5G or Edge for normal day to day use together with voice as that function is not very taxing on the battery.
    6. Additional  [ Developer Options ] tweaks can be done, they may or may not extend battery life. 

      Developer Options performance tweaks


      [ Developer Options need be enabled before following tweaks ]

      1.  Window animation scale/ Transition animation scale/ Animator duration scale/ = OFF. What these 3 options do is, free up CPU/GPU resources which use considerable battery power. If one can do without these        " fancy gimmicks ", you will notice a much faster & responsive phone/ tablet. [ personally, I keep Transition animation scale = 0.5 and disable the other two. ] 
      2. " Enable ( check ) [ Do not keep activities ] " is an optional tweak, which basically wipes user data upon the user exiting that app, thus freeing up memory/cpu/gpu cycles. [ see, what usually happens is when an user exits a running app by pressing Back button, you minimize the app, but app continues to run in the background consuming battery/cpu/memory resources. That is why, after i exit an app, I manually clear background running app either via a dedicated app such as Clean Master or, android OS specific native Task Manager/ RAM Manager/ Clear memory " Synology NAS & DS File android app ", may have problems in file transfers to & from NAS. 

        01:40 20 Nov 2013 57 % battery level,
        30.79 MB 3.5G Data usage

        08:38 20 Nov 2013 54 % battery level,
        30.79 MB 3.5G Data usage 

        Apps used in this article to monitor android smartphone/ tablet - Google Play Store

        • Clean Master [ comes with a inbuilt desktop widget called " 1 Tab Boost " ]
        • Battery Monitor Widget 
        • 3G Watchdog
        • Airplane Mode Widget by Jason Hull

        2 comments:

        1. Great post. These are really battery saving tricks available in Android which no one really tracks.

          These WiFi setting should make a huge different indeed. But for people who needs email notifications and all to be notified right at the delivery time, have to keep it default. Of course that "Network Notification" check box can be unchecked.

          I basically use 2G and just switch back to HSPA when ever I need to use fast internet. Make a huge different in battery life. For general usage of internet like for chatting and be online, email notifications etc. 2G speed is more than enough.

          Settings under "Developer Options" are very important. I have been using 0.5x for transition/animator scales. Turning them totally off makes android ugly as hell.

          Enabling "Do not keep activities" is also very very important for device speed and battery life as most ppl exit from apps by pressing the home button which actually minimizes the app. It does not exit the app. So it runs in the background consuming battery, RAM and processor.

          Apart from these restarting the device may be once 2 days is another good practice. That way the OS runs fresh without any errors.

          This way I keep my NOTE II alive for 2-3 days with single charge.

          ReplyDelete
        2. thx, glad u liked it. yes, i forgot to add bout the transition effect, keep atleast one of them set at 0.5. as for me, i cant disable ' do not keep activities " coz of my NAS. this was huge effort on my part, took me a full day to organize the notes for this article, finally posted it at 2 AM. LOL

          ReplyDelete