Android Battery Information from File system

Android Better information from File System

Today, I’d like to take a dive into some technical specifics. This isn’t for everyone, but I think some people– mostly Android developers!– will find it useful.

In Linux, applications collect the battery status through sysfs, where the battery status is located in /sys/class/power_supply/. Different platforms, however, may give us a different directory layout under /sys/class/power_supply/, but Android hardcodes the directory layout to /sys/class/power_supply/. From the directory /sys/class/power_supply/battery/, there is some files that contains the newest information about the real battery:

1. uevent:

Contains some information including: name, type, status, health, present, technology, capacity, for example:

POWER_SUPPLY_NAME=battery POWER_SUPPLY_TYPE=Battery
POWER_SUPPLY_STATUS=Charging POWER_SUPPLY_HEALTH=Good
POWER_SUPPLY_PRESENT=1 POWER_SUPPLY_TECHNOLOGY=Li-ion
POWER_SUPPLY_CAPACITY=93

2. batt_vol:

Contains the information about the current voltage of the battery: for example, 417

3. batt_temp:

Contains the information about the current temperature of the battery: for example, 310

So, we can access to that directory, read those related files and get the appropriate information about the battery.