Techniques to Reduce Android Device Power Consumption and Prevent Shutdown During Automated Testing

During large‑scale Android testing, devices often run out of battery and shut down, increasing operational costs; this article describes methods to reduce power consumption and prevent power‑off interruptions.

By defining low (20%) and normal (60%) battery thresholds, tasks are paused when devices fall below the low level and resumed when above normal; the current battery level is obtained via adb shell dumpsys battery .

~$ adb shell dumpsys battery
Current Battery Service state:
  AC powered: false
  USB powered: true
  Wireless powered: false
  Max charging current: 0
  Max charging voltage: 0
  Charge counter: 37000
  status: 5
  health: 2
  present: true
  level: 100
  scale: 100
  voltage: 4358
  temperature: 300
  technology: Li-poly

To lower screen power draw, set the brightness adjustment mode to manual and then modify the brightness value (0‑255) using shell commands.

# Set brightness adjustment mode to manual (0) or automatic (1)
settings put system screen_brightness_mode 0
# Get current brightness mode
settings get system screen_brightness_mode

# Get current brightness (0‑255)
settings get system screen_brightness
# Set brightness to 150 (0‑255)
settings put system screen_brightness 150

After tasks finish, close all third‑party apps and lock the screen to avoid background power drain. List installed third‑party packages with pm list packages -3 and terminate each using am force-stop .

$ adb shell pm list packages -3
package:com.sankuai.meituan
package:com.tencent.mm
package:com.liuzh.deviceinfo
package:com.ct.client

adb shell am force-stop com.ct.client

Set the device screen‑off timeout to 30 seconds to keep the device awake during script execution.

adb shell settings put system screen_off_timeout 30

Enable automatic time synchronization to avoid time‑related errors.

adb shell settings put global auto_time 1

Adjust the device volume via reflection: obtain the IAudioService object, query the current ringer mode, and set it to normal, then set specific stream volumes.

Method getServiceMethod=Class.forName("android.os.ServiceManager").getDeclaredMethod("getService", String.class);
IBinder binder = (IBinder) getServiceMethod.invoke(null, "audio");
Method asInterfaceMethod = Class.forName("android.media.IAudioService$Stub").getMethod("asInterface", IBinder.class);
IAudioService iAudioService = (IAudioService) (IInterface) asInterfaceMethod.invoke(null, binder);

int mode = iAudioService.getRingerModeExternal();

iAudioService.setRingerModeExternal(AudioManager.RINGER_MODE_NORMAL, "com.android.settings");
iAudioService.setRingerModeInternal(AudioManager.RINGER_MODE_NORMAL, "com.android.settings");

Note: on some Huawei devices this may raise a SecurityException due to missing STATUS_BAR_SERVICE permission.

# Huawei specific error example
java.lang.SecurityException: request policy access status for another package: uid 2000 does not have android.permission.STATUS_BAR_SERVICE.
    at android.os.Parcel.createException(Parcel.java:1953)
    ...

Finally, set stream volume using iAudioService.setStreamVolume(streamType, volume, 0, null) , where streamType can be AudioManager.STREAM_MUSIC , STREAM_ALARM , etc.

// Example: set music volume to level 5
iAudioService.setStreamVolume(AudioManager.STREAM_MUSIC, 5, 0, null);