How to set the Critical battery action to 'Do Nothing' in Windows Vista

With the ongoing troubles of ACPI incorrectly reporting battery life on many notebooks, many users wish to gain access to the hidden energy supply by disabling the battery alarms. For whatever reason, Windows Vista does not allow the 'Critical battery action->On battery' option to be set to 'Do Nothing' using the Power Options GUI--it is simply not in the drop-down list.

After digging through the registry and attempting to change the key values manually with regedit.exe to no avail (unable to change the value due to write permissions), I found out about a command line version of power options included with Windows Vista.

The tool is powercfg.exe

To change the 'Battery->Critical battery action->'On battery' setting to "Do nothing" using powercfg.exe

1. activate the power scheme you want to modify.
2. open an elevated command console (windows key, type 'cmd' in start menu, press "ctrl+shift+enter", click 'continue')
3. execute "powercfg -setdcvalueindex SCHEME_CURRENT SUB_BATTERY BATACTIONCRIT 0"
4. your current power scheme will show "Battery->Critical battery action->On battery: Do nothing" despite the option being unavailable in the drop box.

If you want to change the value of a non-active power scheme, you can execute 'powercfg -L' and replace SCHEME_CURRENT with the GUID of your choice.
To see all the options, run 'powercfg /?'

 

Thank you very much!

 

I think you can configure this using the user interface as well.

1. Right click on the power icon (battery) near the clock in the system tray and select 'Power Options'
2. Press the link button titled: 'Change plan settings'
3. Select 'Change advanced power settings' link button
4. From the list of options scroll to 'Battery' and under that 'Critical battery action'. You can select from the drop down lists when you click the current action what you would like to do. Also, in this advanced settins window you can select another power plan from the drop down list and change settings there.

I did not require elevated privileges to change these options, but there is a link button to do that, should you want to change something that requires it.

 

Of course that is how we _should_ be able to change it... but unfortunately, Microsoft decided to remove the option 'Do Nothing' from that particular drop down list... or perhaps it is a bug?

 

understanding the shortcomings of any apps/utilities, having a warning is better than none when working with battery's life left, hate to see some of the work goes down the tube when the laptop decides to shut itself off due to no more juice available -

nice info, regardless - thx

cheers ...

 

Just a hunch...

Whilst I have not checked the Vista's registries... I remember that Win2000 and XP had so many registry settings that gave you options/tweaks which you could not otherwise see with the normal Windows programs and menus, or interface.

And I think what Plex has pointed out with the Command Line entry is essentially changing the registry but via the command prompt or script.

 

Correct, the entry is in the registry. The only problem with editing the registry entry via regedit.exe is that Vista denies access. I am running regedit.exe with admin privileges. It seems that only the command line utility can change the particular registry entry.