Turning power saver mode on helps to increase battery life.
It reduces the usage of phone features that drain the battery such as the CPU and display.
Slide the Notifications panel open.
If you want to choose which phone features to conserve power for, tap the
Power saver notification first before you turn power saver mode on.
HTC Desire 500
automatically disconnects from the mobile network after 15 minutes when the screen is off and the data connection is idle (no download activity, streaming, or data usage). It reconnects and then disconnects periodically when the data connection is idle to save battery power.
Keep in mind though that the
Sleep mode option for the data connection in
Settings > Power, when enabled, overrides power saver mode.
Tap the check box next to the
Power saver notification to turn power saver mode on or off.