** Usage
To load this module, place
#+BEGIN_SRC lisp
    (load-module "battery-portable")
#+END_SRC

in your =.stumpwmrc=. Battery information is then available via %B
in your mode-line config.

If you have an older kernel and the above doesn't work, add
#+BEGIN_SRC lisp
    (setf stumpwm.contrib.battery-portable:*prefer-sysfs* nil)
#+END_SRC
below the above line.

