Re: how to control battery charge level on a laptop

[RVP <rvp%SDF.ORG@localhost>]

On Wed, 22 Oct 2025, Henry wrote:

> My suspicion is that the original battery was being dangerously
> overcharged.  I don't want that to happen again.

The battery controller, unless it's very crappy, should take care of this.
No, what's worrying is this:

> With the brand new battery, `envstat -d acpibat0` says:
>                  Current  CritMax  WarnMax  WarnMin  CritMin  Unit
> design voltage:    7.700                                         V
>       voltage:     8.669                                         V

Current voltage should never exceed the design voltage. Unless those are just
erroneous values being read via the older "_BIF" ACPI handle. (NetBSD doesn't
use the newer "_BIX" methods.) Batteries made these days sometimes implement
the "_BIF" methods very poorly. I have a laptop which shows stupid values
(design voltage of 0 V, for instance) on NetBSD, but is OK on Linux and FreeBSD.

Can you see what Linux says?

-RVP