Script that calculates average battery percentage for a laptop with 2 batteries

t460_battery.sh

#!/bin/sh                                                                       
                                                                                
# This script can be used to determine the average load of 2 batteries          
# It requires the acpi command.                                                 
                                                                                
battA=$(acpi | grep "Battery \0" | cut -d" " -f 4 | sed "s/[^0-9]//g")          
battB=$(acpi | grep "Battery 1" | cut -d" " -f 4 | sed "s/[^0-9]//g")           
                                                                                
avg=$((($battA+$battB)/2))                                                      
                                                                                
if [ "$(acpi | grep "Discharging" | wc -l)" = 0 ]; then                         
        echo [$avg%]                                                            
else                                                                            
        echo -e  "$avg%"                                                        
fi