xbatmon-simple: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On Debian possible default full paths are:

/usr/bin/xbatmon-simple - from package: chiark-utils-bin

You may install the required package with command apt-get install {package}

Error in other languages:
xbatmon-simple: bevel nie gevind nie
xbatmon-simple: comandă negăsită
xbatmon-simple: comando não encontrado
xbatmon-simple: commande introuvable
xbatmon-simple: command not found
xbatmon-simple: käsku ei ole
xbatmon-simple: không tìm thấy lệnh
xbatmon-simple: komanda nerasta
xbatmon-simple: Kommando nicht gefunden.
xbatmon-simple: kommandot finns inte
xbatmon-simple: komut yok
xbatmon-simple: nie znaleziono polecenia
xbatmon-simple: níor aimsíodh an t-ordú
xbatmon-simple: no se encontró la orden
xbatmon-simple: no s'ha trobat l'ordre
xbatmon-simple: opdracht niet gevonden
xbatmon-simple: parancs nem található
xbatmon-simple: perintah tidak ditemukan
xbatmon-simple: príkaz nenájdený
xbatmon-simple: příkaz nenalezen
xbatmon-simple: команда не найдена
xbatmon-simple: командата не е открита
xbatmon-simple: 命令找不到
xbatmon-simple: コマンドが見つかりません