I was using fluxbox on my notebook, but it missed battery indicator.Is there any battery monitor on fluxbox?
[solved]
install wmbattery then add it to startup script.
You might consider using conky which is a great lightweight system monitor that can not only monitor your battery state but many, many other functions of your computer.
In Manjaro Fluxbox there is a simple battery indicator applet called cbatticon.
I prefer mate-power-manager, which is more complete and looks better.