Simple Battery Indicator for Gnome, since Ubuntu 12.04 trolled me, I wrote my own ... fuck you ;)

simple_battery_indicator.py

#!/usr/bin/env python
import sys
import gtk
import appindicator
import re
import commands

PING_FREQUENCY = 30 # seconds

class CheckBattery:
    def __init__(self):
        self.ind = appindicator.Indicator("simple-battery-indicator",
                                           "battery-empty",
                                           appindicator.CATEGORY_APPLICATION_STATUS)
        self.ind.set_status(appindicator.STATUS_ACTIVE)
        self.menu_setup()
        self.ind.set_menu(self.menu)

    def menu_setup(self):
        self.menu = gtk.Menu()
        self.status_item = gtk.MenuItem("Status")
        self.status_item.show()
        self.menu.append(self.status_item)
        #self.quit_item = gtk.MenuItem("Quit")
        #self.quit_item.connect("activate", self.quit)
        #self.quit_item.show()
        #self.menu.append(self.quit_item)

    def main(self):
        self.check_battery()
        gtk.timeout_add(PING_FREQUENCY * 1000, self.check_battery)
        gtk.main()

    def quit(self, widget):
        sys.exit(0)

    def check_battery(self):
        # python n00b needs to fall back to ruby ;)
        percent, icon, charging, hours = commands.getoutput("""ruby -e '
        info     = `cat /proc/acpi/battery/BAT1/*`
        charging = info.match(/charging state:\s*(\D+)\n/)[1]
        full     = info.match(/last full capacity:\s*(\d+)/)[1].to_f
        current  = info.match(/remaining capacity:\s*(\d+)/)[1].to_f
        rate     = info.match(/present rate:\s*(\d+)/)[1].to_f
        percent  = (current / full) * 100
        bpercent = ((percent / 20).round * 20).to_s
        bpercent = "0#{bpercent}" if bpercent.size == 2
        hours    = (current / rate).round(2)
        puts "#{percent.to_i} battery-#{bpercent}#{charging == "charging" ? "-charging" : ""} #{charging} #{hours}"
        '""").split()
        self.ind.set_icon(icon)
        self.status_item.set_label(percent + "% " + charging + "\n" + hours + " hours left")
        return True

if __name__ == "__main__":
    indicator = CheckBattery()
    indicator.main()

https://wiki.ubuntu.com/DesktopExperienceTeam/ApplicationIndicators is a nice read