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Battery Optimization for Android Apps

74 points by vinnyglennon 12y ago

dkopi 12y ago
I really hope Google one day adds a "battery usage" and "network usage" rating for apps in the play store. Common users are pretty helpless when it comes to figuring out which apps are killing their phone.
- edude03 12y ago
  Better yet, I hope google exposes "battery historian" via the battery menu on android phones.
  - shitlord 12y ago
    Yeah, the fact that we Android users need to use apps like Better Battery Stats is pretty telling. They could at least stick it in the developer settings somewhere.
kec 12y ago
One other thing this deck doesn't go into but has a huge impact (for games at least) is frame rate. Higher frame rates require the GPU to get the work done in a shorter amount of time and make it less likely that the GPU will be able to switch to an idle power save state. A good example of this in action is the game Threes. The developers implemented a "power save" feature in the game which simply cuts the frame rate in half[0], causing the app to consume noticeably less battery. 0: http://asherv.com/threes/support/ http://asherv.com/threes/support/
- corysama 12y ago
  I worked on a mobile FPS that was able to run at full-rez, 60fps on an iPad3. Unfortunately, doing so drained the battery faster than the wall charger could refill it! So, we shipped locked at 30fps and provided a "battery hog mode" option to the user.
  - snuxoll 12y ago
    What level was the battery at? Past 80% most Lithium Ion or Lithium Polymer battery controllers will change to a trickle charge which could explain it.
    - corysama 12y ago
      You could drain the battery completely while charging.
      - voltagex_ 12y ago
        Ingress will do this on a Nexus 5 - except for wall chargers that are delivering the full ~1.7A (which are very very very few)
        fixedd 12y ago
        Ingress can do this on a Galaxy Nexus with a 2A external battery pack (or, ya know, car). I was only able to help with about 1/2 of an Interitus event cause my phone kept dying and I'd have to wait a bit to bring it back online. I hate my phone.
zxcvgm 12y ago
I thought this slide deck would cover the improvements introduced by Project Volta [1] in Lollipop. They introduced a JobScheduler API that developers can use to perform the batching that he described, as well as the Battery Historian for better power profiling. [1] https://developer.android.com/about/versions/android-5.0.html#Power https://developer.android.com/about/versions/android-5.0.htm...
- christop 12y ago
  On that topic, this is a much better talk: http://commonsware.com/presos/8469_Murphy.pdf http://commonsware.com/presos/8469_Murphy.pdf
yardie 12y ago
Why is any of this even necessary at this stage. Android has been around for 7 years, 5 major versions, and many more subversions. Power management should be solved by now. The OS should be managing this. All power management options should be applied to all apps and only those that need an exemption should code around it.
- joshvm 12y ago
  In my experience there are two drains on power: - The screen. Doesn't matter what the app is, if the screen is on the battery plummets - Network hunting. If there's no WiFi, but the radio is on then it wastes loads of battery trying to find a network.
  - fixedd 12y ago
    Don't forget GPS... GPS lock murders.
- corysama 12y ago
  Because apps are commonly requesting that the device perform actions that require excessive amounts of power according to the laws of physics. Can you imagine the complaints the OS devs would get if they stepped in to intervene? "I noticed your app made a separate request to the ad server every 30 seconds (between menus). So, I decided to batch up your requests and only send them every 10 minutes."
- cryptoz 12y ago
  It's a balancing act between giving devs power over their code and managing battery. You could say that Apple 'solved' the problem by preventing developers from doing really cool things, whereas Google/Android still have battery concerns but devs have built awesome apps that depend on that flexibility. This isn't something than can be 'solved'. All the time, Google will make improvements to the OS (like JobScheduler in Lollipop) and devs will get better at managing their resources. Slowly we'll all get better battery performance. I make PressureNet, which runs in the background on Android in 10-minute intervals to get GPS, barometer measurement, and network lock. Maintaining a good battery life isn't easy, but it is possible. https://play.google.com/store/apps/details?id=ca.cumulonimbus.barometernetwork https://play.google.com/store/apps/details?id=ca.cumulonimbu...
joosters 12y ago
An ad/tracker/stats blocker sounds like it might give your battery life a huge boost here. Think of the network traffic saved!
voltagex_ 12y ago
Also https://developer.android.com/training/monitoring-device-state/index.html https://developer.android.com/training/monitoring-device-sta...

74 points by vinnyglennon 12y ago

dkopi 12y ago

I really hope Google one day adds a "battery usage" and "network usage" rating for apps in the play store. Common users are pretty helpless when it comes to figuring out which apps are killing their phone.

edude03 12y ago
Better yet, I hope google exposes "battery historian" via the battery menu on android phones.
- shitlord 12y ago
  Yeah, the fact that we Android users need to use apps like Better Battery Stats is pretty telling. They could at least stick it in the developer settings somewhere.

kec 12y ago

One other thing this deck doesn't go into but has a huge impact (for games at least) is frame rate. Higher frame rates require the GPU to get the work done in a shorter amount of time and make it less likely that the GPU will be able to switch to an idle power save state. A good example of this in action is the game Threes. The developers implemented a "power save" feature in the game which simply cuts the frame rate in half[0], causing the app to consume noticeably less battery. 0: http://asherv.com/threes/support/ http://asherv.com/threes/support/

corysama 12y ago
I worked on a mobile FPS that was able to run at full-rez, 60fps on an iPad3. Unfortunately, doing so drained the battery faster than the wall charger could refill it! So, we shipped locked at 30fps and provided a "battery hog mode" option to the user.
- snuxoll 12y ago
  What level was the battery at? Past 80% most Lithium Ion or Lithium Polymer battery controllers will change to a trickle charge which could explain it.
  - corysama 12y ago
    You could drain the battery completely while charging.
    - voltagex_ 12y ago
      Ingress will do this on a Nexus 5 - except for wall chargers that are delivering the full ~1.7A (which are very very very few)
      - fixedd 12y ago
        Ingress can do this on a Galaxy Nexus with a 2A external battery pack (or, ya know, car). I was only able to help with about 1/2 of an Interitus event cause my phone kept dying and I'd have to wait a bit to bring it back online. I hate my phone.

zxcvgm 12y ago

I thought this slide deck would cover the improvements introduced by Project Volta [1] in Lollipop. They introduced a JobScheduler API that developers can use to perform the batching that he described, as well as the Battery Historian for better power profiling. [1] https://developer.android.com/about/versions/android-5.0.html#Power https://developer.android.com/about/versions/android-5.0.htm...

christop 12y ago
On that topic, this is a much better talk: http://commonsware.com/presos/8469_Murphy.pdf http://commonsware.com/presos/8469_Murphy.pdf

yardie 12y ago

Why is any of this even necessary at this stage. Android has been around for 7 years, 5 major versions, and many more subversions. Power management should be solved by now. The OS should be managing this. All power management options should be applied to all apps and only those that need an exemption should code around it.

joshvm 12y ago
In my experience there are two drains on power: - The screen. Doesn't matter what the app is, if the screen is on the battery plummets - Network hunting. If there's no WiFi, but the radio is on then it wastes loads of battery trying to find a network.
- fixedd 12y ago
  Don't forget GPS... GPS lock murders.
corysama 12y ago
Because apps are commonly requesting that the device perform actions that require excessive amounts of power according to the laws of physics. Can you imagine the complaints the OS devs would get if they stepped in to intervene? "I noticed your app made a separate request to the ad server every 30 seconds (between menus). So, I decided to batch up your requests and only send them every 10 minutes."
cryptoz 12y ago
It's a balancing act between giving devs power over their code and managing battery. You could say that Apple 'solved' the problem by preventing developers from doing really cool things, whereas Google/Android still have battery concerns but devs have built awesome apps that depend on that flexibility. This isn't something than can be 'solved'. All the time, Google will make improvements to the OS (like JobScheduler in Lollipop) and devs will get better at managing their resources. Slowly we'll all get better battery performance. I make PressureNet, which runs in the background on Android in 10-minute intervals to get GPS, barometer measurement, and network lock. Maintaining a good battery life isn't easy, but it is possible. https://play.google.com/store/apps/details?id=ca.cumulonimbus.barometernetwork https://play.google.com/store/apps/details?id=ca.cumulonimbu...

joosters 12y ago

An ad/tracker/stats blocker sounds like it might give your battery life a huge boost here. Think of the network traffic saved!

voltagex_ 12y ago

Also https://developer.android.com/training/monitoring-device-state/index.html https://developer.android.com/training/monitoring-device-sta...