Samsung Android phones often experience inexplicably fast battery drain. After using Better Battery Stats to investigate, the culprits are identified as gpsd and lli_pm_wlock. These two processes combined can drain more than 10% of the battery per hour on standby. After extensive research, a solution has finally been found.

gpsd

The issue arises because many apps automatically trigger the location function, even if location services are turned off or app permissions to access location are disabled. These apps will still activate gpsd in the background, continuously attempting to locate. The solution is to set permissions for the gpsd file. Follow the instructions in the link to use gscript to control the gpsd switch.

http://download.csdn.net/detail/o8xv0123/6881219?web=web

lli_pm_wlock

This is a standby process intended to save power. However, under certain special conditions, such as when the phone signal is set to 4G only or 3G only, it continuously searches for signals, causing a sharp increase in power consumption. The solution is to set the phone signal to match the actual local conditions. If 4G is available, it should be set to 4G/3G/2G auto-select.

http://forum.xda-developers.com/showpost.php?p=62519112&postcount=1254