Getting more from your battery

Gnome Power Management logoFollowing my previous article on the Gnome Power Management applet, I want to talk about another new functionality of this tool that got added with the latest version of Gnome (2.18 available with the coming Ubuntu Release).

This new facility helps you getting more information from your battery and is available via the menu of the Gnome Power Management applet when clicking on it with the left button. In the menu, the first entry should be about your battery with the charge information.

Click on the mentioned entry and a nice balloon like below will appear with information on your battery.

GPM - Information status about the battery

Just to clarify the various entries (if necessary):

  • Vendor is the actual manufacturer of the battery, which might be different than the laptop manufacturer,
  • Technology is the type of your battery, whether it is the old Nickel Metal Hybrid (NiMH) with lots of memory effect, or newer ones like Lithium Ion or Lithium Polymer,
  • Serial number is self-explaining,
  • Model is the manufacturer model name, in my case it is the manufacturer of my laptop,
  • Capacity is a percentage number which gives an idea of the current maximum capacity compared to the designed one (see after). It gives a rough idea of what you still have. So I lost a quarter of autonomy after more than 3 years, not too bad ;-)
  • Current charge is the current power that is available on your battery, if it is fully charged it is the same as your last full charge. If you are currently running on battery it indicates the charge left,
  • Last full charge is the amount of energy that the battery was able to store when it was last fully charged,
  • Design charge is the amount of energy that the battery could hold once manufactured. So the newer the battery, the closer is the last full charge to this figure.

If you are a freak to get even more information, you can use the command line (thanks to carthik for this hint). Just open a terminal (Gnome “Applications” menu -> “Accessories” -> “Terminal”)

$ cd /proc/acpi/battery/

There you will find a number of directory in the form BATn where n is a number, each corresponds to a battery compartment of your laptop. Mine is in BAT0, so here is the rest of the commands:

$ cd BAT0
$ cat *

The result was:

alarm:                   4800 mWh
present:                 yes
design capacity:         48000 mWh
last full capacity:      35830 mWh
battery technology:      rechargeable
design voltage:          11100 mV
design capacity warning: 4800 mWh
design capacity low:     1454 mWh
capacity granularity 1:  480 mWh
capacity granularity 2:  480 mWh
model number:            DELL Y13384
serial number:           2879
battery type:            LION
OEM info:                Sanyo
present:                 yes
capacity state:          ok
charging state:          charged
present rate:            unknown
remaining capacity:      48000 mWh
present voltage:         12404 mV