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Is it possible to make ubuntu always think that system is on battery supply?

Thank you.

4xy
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  • What's the purpose of this? May I ask. – xangua Dec 18 '16 at 23:21
  • Sure, when my laptop is on battery ubuntu works gently with the CPU fan. But when on AC fan sticks on max speed due to unknown reason. Please, see this for more info http://askubuntu.com/questions/841430/ubuntu-16-04-lts-fan-works-at-max-speed-on-hp-envy-6-1154er. If this condition occurs it's just enough to disconnect laptop from the AC and fan's speed after a couple of seconds gets low. – 4xy Dec 18 '16 at 23:29

1 Answers1

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First of all, the AC and Battery power information normally is supplied to the kernel via an embedded controller on the motherboard and this ultimately gets handled by ACPI via the kernel ACPI driver layer and so userspace programs get this kind of AC/Battery data via this mechanism.

Normally you don't have any smart controls to tell the underlying hardware to make the system believe it is on battery power when in fact it is being powered by AC. A lot of machines have BIOS/Embedded controller interactions outside the domain of the kernel control that twiddle fan speeds; so you may find there is no easy way to make the operating system do what you are requiring.

Some laptops do have fan controls in their platform drivers, but a lot don't - the fan control is driven by the BIOS and not under kernel control.

Colin Ian King
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  • When I had windows on this laptop there were no such an issue with the CPU fan... It seems the only solution is to buy Ubuntu certified laptop. – 4xy Dec 19 '16 at 13:36