UPS2

Enable I2C in raspi-config

sudo raspi-config
-Interfacing Options
-I2C
-Enable
-Yes

View battery Info

wget https://github.com/geekworm-com/UPS2/raw/master/viewinfo.py  
#edit viewinfo.py and modify battery capacity  
nano viewinfo.py  
#.Change 2500 to your battery capacity (mAh)  
MY_BATTERY_CAP = 2500