(I didn't get your reply on mail, so I am replying this way)
I am using CoreBoot with SeaBIOS as a payload for ThinkPad T430s to boot FreeBSD (but with Linux problem is same). DSDT provided by CoreBoot is missing battery charge start (BCTG, BCCS)
and
stop (BCSG, BCSS) thresholds.
https://review.coreboot.org/c/coreboot/+/23178 (needs a rebase) implements the things you are asking for.
Nice :) It is not merged, so cherry pick needs to be used, but anyway, great that is already in review. Also, when seeing patchset, it is definitively over my ACPI skillset.
Just wondering is this a mainline driver in FreeBSD? Linux got one quite recently.
It is not yet merged but I suppose it will be soon: https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=234403
Tested and it works :) % sysctl dev.acpi_ibm.0.bat0_charge_{start,stop} dev.acpi_ibm.0.bat0_charge_start: 20 dev.acpi_ibm.0.bat0_charge_stop: 81 Thank you all for great work!
Additional question (still related to ThinkPad EC): - is it possible to make some sound/tone when battery is at critical charge and/or charger is disconnected? There is "low_battery_beep" and "power_management_beeps" but I didn't manage to get it working on T430s