Display network name in xmobar

The bar is stopped because you are starting it as a background job but it is configured to read from stdin (standard input). The xmobar process is not terminated, you should still see the bar.

If the bar is not visible at all, it could be because it is covered by your desktop. You are already importing XMonad.Hooks.ManageDocks and using avoidStruts so you could also use the manageDocks hook it provides and make xmobar behave like a dock (overrideRedirect=False in the configuration).

You configured xmobar to read from standard input, so you should have something writing to its standard input. It can be anything, not necessarily xmonad.

You don't have to start xmobar from xmonad, but if you want to show the output provided by XMonad.Hooks.DynamicLog for instance, it's easier to start it from there.

You can use the xmobar convenience function, as explained in the doc :

main = xmonad =<< xmobar myConfig

Or you can use the statusBar function and define your own pretty printing format :

main = xmonad =<< statusBar "xmobar" myPP myToggleKey myConfig

Or directly use dynamicLogWithPP as shown in the example in the documentation :

main = do
    h <- spawnPipe "xmobar -options -foo -bar"
    xmonad $ defaultConfig {
      ...
      logHook = dynamicLogWithPP $ defaultPP { ppOutput = hPutStrLn h }

spawnPipe runs the given command and returns a Handle to its standard input, that handle is then used in defining the ppOutput function.

This is no ready solution, but an idea: I would use osd_cat which comes in the package xosd in Fedora Linux together with a cronjob, that checks your battery status.

You can edit your cronjobs with

crontab -e

and you find your battery status in /sys/class/power_supply/, and there it is in my case BAT1/ with some files charge_now and charge_full. With those files, that is with

/sys/class/power_supply/BAT1/charge_now
/sys/class/power_supply/BAT1/charge_full

you could find the percentage remaining in your battery, which could then show you a big message with osd_cat (onscreen display).