Battery Status is a project for GNOME, that shows information about laptop battery state. It has some additional features, so usual icon of GNOME Power Manager can be removed from Notification/Indicator Area. Battery Status doesn't rely on GNOME Power Manager directly, but counting on presence in system for some useful integration with it.

Contents

Rationale
Installation
Basic Usage
Additional settings
CPU scaling controversial
Other Devices
GNOME Collaboration
Technical Details
Links

1. Rationale

GNOME Power Manager's Notification Icon has got main user interface shortcoming (if its purpose - to show battery information) - for see exactly battery percentage or battery lifetime, user should hover mouse to icon, wait couple seconds, and only then user could see required information (tool tip - the bad way for getting information in such cases). Such behavior pretty annoying, so Battery Status' applet hasn't got such behavior and allow to user see percentage/lifetime/charge time of battery right in panel next to icon. Also, using GNOME Power Manager's Icon, user can't direct place, where exactly battery information should be showing.

$/!\$ Problems, which has been described above, can be solved by using battstat-applet (Battery Charge Monitor applet), but it has some historical architectural disadvantages (such as relies on ACPI and HAL) and user interface problems (such as using non-consistent icons) itself, and by these reasons this applet has been declared as obsolete, has been deprecated and removed from set of standard gnome-applets package in such key GNOME Desktop GNU/Linux distributions as Fedora and Ubuntu (see also this [1] discussion for more information)

Another improvement - warning message about critical battery charge. GNOME Power Manager supports notifications (via notification-daemon/notify-osd), and this is very useful. But when user is deep in thoughts about his current work/task/action/etc, his locus of attention (see [2] for more details) may just couldn't see notification-like warning about critical low (which very important if user hasn't get access for power) - it should be message on top of all windows.

"Device Information" dialog (which has been totally deprecated in last versions) from GNOME Power Manager's icon has been replaced by "Battery Status" dialog in Battery Status. In "Device Information" dialog all battery information puts in one heap, but in "Battery Status" dialog battery information divided by two (three) easy-readable areas - one for battery capacity, another for battery charge (and another for battery information).

2. Installation

Battery Status can be installed from package, or from sources. For better experience you should re-login after installation.
Packages for Ubuntu can be found in this launchpad repository:
http://launchpad.net/~iaz/+archive/battery-status
Debian/Ubuntu-related source code tree (with debian/ directory for packaging):
https://code.edge.launchpad.net/~iaz/battery-status/trunk
non-Debian/Ubuntu source code tree (without debian/ directory):
http://github.com/ia/battery-status
Command for installation from sources:

# python setup.py install
# GCONF_CONFIG_SOURCE=$(gconftool-2 --get-default-source) gconftool-2 --makefile-install-rule /usr/share/gconf/schemas/battery-status.schemas

Command for installation in Ubuntu from Launchpad's PPA:

# add-apt-repository ppa:iaz/battery-status
# apt-get update
# apt-get install battery-status

3. Basic Usage

For place applet to panel, right click on it, and select "Add to Panel..." > "Battery Applet"
After adding, by default applet shows icon only.
From main menu user (by default) can get access to:

"Battery Status" dialog
Power Statistics (provided by GNOME Power Manager)
"Show" setting
CPU frequency scaling (provided by gnome-applets/cpufreq-applet)
"Power Management..." preferences (provided by GNOME Power Manager)

From context menu (by clicking right mouse button at applet) user can get access to:

Bug Reporting (Ubuntu only - Apport/Launchpad integration)
GNOME Power Management Help (provided by GNOME Power Manager)
"About" information dialog
generic applet-related options (such as "Remove", "Move", "Lock To Panel")

For run "Battery Status" as Application Indicator (in latest versions of Ubuntu, for example), run in Terminal:

$ /usr/lib/battery-status/battery-status --indicator

For autostart this command on login, you can add it in "System" > "Preferences" > "Startup Applications".

4. Additional settings

Battery Status uses GConf for settings. All keys can be found in /apps/battery_status.
Description for each key you can find using gconf-editor.

5. CPU scaling controversial

If you are interested in Power Management, you've probably heard of Matthew Garrett and saw his presentations about Power Management [3]. According to common sense, such feature as "CPU frequency scaling" is not effective and productive from point of power management's view, but this feature has been supported in Battery Status, because some users still keep using it. However, I think that this part of Battery Status should be improved somehow (more flexible power profiles, maybe?).

6. Other Devices

Battery Status currently has support of laptop batteries only, but I've tried to make D-Bus/UPower/GNOME Power Manager report percentage of 3 RF mices, one bluetooth keyboard and couple phones - looks like that UPower/GNOME Power Manager just can't provide power state of such devices, so I haven't hardware for testing and implementing such feature at this moment.

7. GNOME Collaboration

I'm sorry for not doing this as a part of GNOME Power Manager, but I don't know C well enough for such kind of development as applets. Also I don't have plans yet for trying to push Battery Status in gnome-applets - my project is still pretty unstable and buggy for this.

8. Technical Details

Battery Status written in Python with using:

PyGTK - python bindings to GTK library
Bonobo - for integration application in GNOME panel as applet
D-Bus - for getting power information from UPower/DeviceKit-power and update it on changes
UPower/DeviceKit-power - for getting power information
python-appindicator - python bindings to Application Indicators library
GConf - for keep and manage application settings

9. Links

Homepage: http://live.gnome.org/BatteryStatus
Github page: http://github.com/ia/battery-status
Launchpad page: http://launchpad.net/battery-status

$/!\$ List of (known/reported) bugs: http://bugs.launchpad.net/battery-status
Bug reporting form: http://bugs.launchpad.net/battery-status/+filebug

[1] http://lists.ubuntu.com/archives/ubuntu-desktop/2009-August/002183.html
[2] "The Humane Interface: New Directions for Designing Interactive Systems", Jeff Raskin
[3.1] http://mjg59.livejournal.com/88608.html
[3.2] http://mirror.linux.org.au/pub/linux.conf.au/2009/Friday/106.ogg
[3.3] http://geeksoc.org/gcds/Matthew%20Garrett,%20Power%20management.ogv

It may sounds strange, but this project has been started a much earlier, than these discussions has been published:
http://chrisjohnston.org/2010/no-more-battery-status-tooltip-in-lucid
http://design.canonical.com/2010/04/battery
http://wiki.ubuntu.com/BatteryStatusMenu

Reviews from WebUpd8 (thank you, guys!): 1 2
Review from OMG!UBUNTU!: How to add a detailed battery indicator to Ubuntu

Also, I can't wait for fixing of this bug - #541858
so indicator could display battery time/percentage right in panel as applet does.

Feel free for sending any questions/advices/UX improvements/bug reports/feature requests/patches/etc.