Battery

Battery.el

Description	Shows the battery status in the mode line
Author	Ralph Schleicher
Maintainer	FSF
Source	http://git.savannah.gnu.org/cgit/emacs.git/tree/lisp/battery.el
Part of Emacs	yes

Basic setup

M-x display-battery-mode

Add your battery status to the Modeline

M-x battery

View battery status

Customization

Gnu/Linux

How to show battery status only on laptop?

if a device have no battery, we don't want to display-battery-mode be enabled.<ref>http://stackoverflow.com/questions/5562974/emacs-is-it-running-on-laptop-or-on-desktop</ref>

(require 'battery)
(when (and battery-status-function
           (not (string-match-p "N/A"
                                (battery-format "%B"
                                                (funcall battery-status-function)))))
  (display-battery-mode 1))

See Also

time