Cannot lower Critical Battery Level in Power Options

[segap21]

How about you try ACPI? Windows Dev Centre Hardware

Design capacity of Low

Indicates the critical battery level at which Windows must immediately shut down or hibernate before the system powers off.

Must be set to a value between 0 and 5 percent of the battery design capacity

This is really interesting reading. Particularly the bit where it says it must be set to a value between 0 and 5 to be ACPI compliant. Really keen to hear what HP has to say when (and if) they call back.

I checked the battery driver that is installed on my laptop. It's ironic that it's listed as ACPI compliant.



I wonder if there is a different ACPI driver that I can install that would bypass HP's one?

 

[segap21]

Well, it's Tuesday and no surprise I did not get the promised callback from HP support. So I took the initiative to call them to follow up. Was told that they will now escalate the matter to the highest priority and I will get a callback in 1 hour. I've waited more than an hour and no word from HP again. Will have to chase them again tomorrow.

In the meantime, I'm gonna try disabling the "Microsoft ACPI-Compliant Control Method Battery" and see if it works. I can verify that when I disable it that it at least lets me change the Critical Battery level in Power Options to any percentage I want. I just need to run the laptop now to see if it is merely cosmetic or if it will actually go lower than 7%. Will report back in a few hours.

 

[segap21]

Here is an update on things:

Disabling the "Microsoft ACPI-Compliant Control Method Battery" does indeed allow me to run the laptop below 7%, however, this method is not a practical workaround because doing so also prevents other useful power management features.

I have an email response from HP and they advise that the MSDN link is only relevant for systems supporting Connected Standby and that the HP Spectre x360 does not support Connected Standby. They further added that ACPI specification 3.9.4 Low Battery Levels do not specify any value as a maximum.

While I agree with what HP has said is true, I do not follow their logic in setting it at 7%. I understand that a computer supporting Connected Standby would experience a far greater battery drain than one that supports only the traditional Sleep/Hibernate power states. If anything, I expect it to be set at something lower than the 5% maximum of a Connected Standby laptop.

I've even gone out to the shops to sample a range of different laptops - ones from Dell, Acer, Asus, Toshiba and Lenovo. All of these other manufacturers have set the critical battery level to at most 5%. Some are 3% and others even allow you to go all the way to 0%. Only HP laptops fix theirs at 7%. I can only infer that only HP has decided that their batteries are somehow inferior to other manufacturers'.

I've sent another email to HP to see if they will issue some sort of fix, so I'll just have to wait to hear from them again.

(After this, I don't think I will buy another HP product ever again)

 

[popeye]

Just for info my Acer allows 5% for lowest setting.