laptop battery status in Bash prompt

# In .bashrc to add the 'battery_status' to PS1
# From a script written here :
#http://www.basicallytech.com/blog/index.php?/archives/110-Colour-coded-battery-charge-level-and-status-in-your-bash-prompt.html, by Rob NEWCATER
# Most of the work is his, I only did minor editing
# Edited by J.DESROCHES to work on my laptop running "Linux version 3.14.2-1-ARCH (nobody@var-lib-archbuild-testing-  #  x86_64-tobias) (gcc version 4.9.0 (GCC) ) #1 SMP PREEMPT Sun Apr 27 11:28:44 CEST 2014" (output of cat /proc/version)
########################################################################################################################

# By : J.D.
# Battery status :

battery_status()
{
        BATTERY=/sys/class/power_supply/BAT1

        CHARGE=`cat $BATTERY/capacity`
        BATSTATE=`cat $BATTERY/status`
# Colors for humans
        NON='\033[00m'
        BLD='\033[01m'
        RED='\033[01;31m'
        GRN='\033[01;32m'
        YEL='\033[01;33m'

        COLOUR="$RED"

        case "${BATSTATE}" in
           'Charged')
           BATSTT="$BLD=$NON"
           ;;
           'Charging')
           BATSTT="$BLD+$NON"
           ;;
           'Discharging')
           BATSTT="$BLD-$NON"
           ;;
        esac

        # prevent a charge of more than 100% displaying
        if [ "$CHARGE" -gt "99" ]
        then
           CHARGE=100
        fi

    # prevent an error if the battery is not in the laptop (e.g. you have two and take out the primary)
    STATE=`cat $BATTERY/state`
    if [ "$STATE" == 'present: no' ]
    then
        echo -e "${RED}nobat"
    exit
    fi

        if [ "$CHARGE" -gt "15" ]
        then
           COLOUR="$YEL"
        fi

        if [ "$CHARGE" -gt "30" ]
        then
           COLOUR="$GRN"
        fi
        echo -e "${BATSTT}${COLOUR}${CHARGE}%${NON}"
}

# and here's my PS1 if people are looking for ideas :

PS1='\[\e[1;34m\]{\d \t}\[\e[m\]\[\e[0;33m\]{\[\e[m\]$(battery_status)\[\e[0;33m\]}\[\e[m\] \[\e[0;32m\]\u\[\e[m\] @ \[\e[0;32m\]\h\[\e[m\] : \[\e[1;34m\]\W\[\e[m\] [\e[1;32m\]\$\[\e[m\]\n\[\e[1;37m\]'