Questions[laptop](ubuntu)

How can I tell if my laptop has a Bluetooth adapter?

If a laptop is powered on and connected to AC power, is there a way to issue a command that tells it not to charge the battery?

EDITED:
Perhaps charging of the battery may be stopped if there were a way to fool the system into thinking the battery is already at 100% charge.

Is it possible to set the default display brightness so you don't have to re-adjust it everytime you reboot? My laptop display is killing my eyes at the login screen already because it starts at 100% brightness every time.

Brightness adjustment keys <Fn + ⇑/⇓> have no effect (although they are recognized by the environment), and I can't change the brightness using GUI tools as well. This seems like a problem in Linux itself, not the desktop environment.

I can change the brightness in Windows OS, so it's not some kind of hardware fault.

Details:
          Lenovo B570 (Model Name: 20093)
          Integrated Intel HD graphics card
          Kubuntu 11.04 (Linux 2.6.38-10-generic, KDE 4.7.0), everything up to date
          No proprietary graphics drivers (only Wi-Fi one)

What I've tried:

• Edit /etc/default/grub↦GRUB_CMDLINE_LINUX_DEFAULT: acpi_osi=Linux, acpi_backlight=vendor, nomodeset. And yes, I did update-grub
• Edit /etc/X11/xorg.conf (no such file, even after sudo dpkg-reconfigure xserver-xorg)
• Edit /proc/acpi/video/VGA/LCD/brightness (no such file)
• sudo setpci -s 00:02.0 F4.B=XX (no effect)
• xbacklight -set XX ("No outputs have backlight property")

How can I fix this issue?

I just learned that some Lenovo laptops include a utility that offers to limit battery charging capacity to within 0–80% in order to slow the attenuation of the battery lifespan:

How can I do this in Ubuntu?