#!/usr/bin/env bash


VOLTAGE_FILE=${1:-"/sys/class/power_supply/hidpp_battery_1/voltage_now"}    


declare -A LEVELS 

LEVELS["4186"]="100"					
# 4156	99%
# ... more shit								
LEVELS["35"]="0"	

VOLTAGE=`cat $VOLTAGE_FILE`
VOLTAGE=${VOLTAGE::-3}

for i in "${!LEVELS[@]}"
do
    if [ "$VOLTAGE" -ge "$i" ]; then
        echo "$LEVELS[$i]"
        break
    fi
done