LEGO MINDSTORMS EV3 battery

modulename: lego_ev3_battery.ko

configname: CONFIG_BATTERY_LEGO_EV3

Linux Kernel Configuration
└─>Device Drivers
└─>Power supply class support
└─>Device Tree and Open Firmware support
└─>GPIO Support
└─>LEGO MINDSTORMS EV3 battery
In linux kernel since version 4.2 (release Date: 2015-08-30)  
Say Y here to enable support for the LEGO MINDSTORMS EV3 battery.

source code:
drivers/power/supply/lego_ev3_battery.c