Sécherre wrote:

Hello !

I've installed Debian Stretch on my HP x2 Detachable with the kernel 4.19.

My battery isn't recognised, so I don't have a battery level in the
systray. Only the command `lshw` is able to identify the battery :

-battery
--- produit: SW02032XL
--- fabriquant: 333-42-1E-A
--- identifiant matériel: 1
--- emplacement: Primary
--- capacité: 32570mWh
--- configuration: voltage=7,7V

I've tried a lot of things without succes. It's seems like the kernel
isn't able to recognise the battery.

Do you have any tips about this problem?

Sylvain

"HP x2 Detachable" doesn't say which one YOU have. That is a family
line of netbooks/tablets. There are models within that family and even
submodels. I did a search at hp.com on what you gave and picked the
first one that show up in its results, which was:

https://support.hp.com/us-en/product...01_title_r0001

When I clicked on the "Software, Drivers and Firmware" button on the
left side, that took me to:

https://support.hp.com/us-en/drivers...model/11572368

The *only* operating system listed is Windows and *only version 10
64-bit. HP provides the drivers only for that setup which is typical of
these type of computers. They don't support earlier versions of
Windows, they don't support any later versions of Windows, and they
definitely don't support any non-Windows operating systems. What makes
you think you can run *NIX on your tablet (with detachable keyboard)?
Unless exposed by standard firmware protocols (APM, ACPI), you need
something (software or device definition) for the OS to access the
hardware.

All hardware needs an interface defined in an OS, so the OS knows how to
communicate with the hardware. If that tablet has a chip to monitor the
battery statistics, something has to tell the OS how to communicate with
that chip. I can only guess which driver package from HP is used to
interface the OS to the hardware, like maybe the "HP PC Hardware
Diagnostics UEFI".

You could try to use programs that poll APM or ACPI functions to find
the battery. Windows expects the battery firmware to get exposed via
ACPI.

https://docs.microsoft.com/en-us/win...implementation

One version of ACPI is documented at:

http://www.acpi.info/DOWNLOADS/ACPI_5_Errata%20A.pdf
Section 3.9 Battery Management, page 45.

To find how Debian might use ACPI to monitor/manage the battery, I did a
search, which was:

https://www.google.com/search?q=debi...ery+management

one of which was:

https://linrunner.de/en/tlp/docs/tlp...anagement.html

Perhaps in the distro you installed, you didn't do a custom install;
that is, maybe you have to select one of the non-default packages to
install to get ACPI battery management included in that OS. Maybe
Debian doesn't come with ACPI battery management functions included or
in its distro, so you're stuck using non-distro tools.

From cursory reading, *NIX users have complained that some distros are
not as efficient on battery life as Windows, and I've seen TLP mentioned
as a solution. Never used Debian but I did find:

https://packages.debian.org/jessie/x...-power-manager

and which says it does battery monitoring.