According to https://github.com/FDOS/fdapm/blob/master/fdapm.txt (not sure if that's the official repository for it), FDAPM from FreeDOS has an "INFO" command which "Displays things like battery fill percentage."

Not sure if this is what you're after though - do you specifically need it to be retrieved via ACPI because your machine doesn't support APM? I assume APM might be a legacy BIOS thing which is no longer supported but I don't know about this stuff. I see there's some ACPI code in that repository too, but from a quick glance it doesn't seem like it's used for getting the battery info.

doshea wrote on 2024-09-21, 00:13:

According to https://github.com/FDOS/fdapm/blob/master/fdapm.txt (not sure if that's the official repository for it), FDAPM from FreeDOS has an "INFO" command which "Displays things like battery fill percentage."

Thanks for that. I'd been looking at fdapm, but didn't notice the "info" command.

doshea wrote on 2024-09-21, 00:13:

do you specifically need it to be retrieved via ACPI because your machine doesn't support APM?

Yup. No APM on there.

jkq wrote on 2024-09-21, 00:28:

Yup. No APM on there.

Thanks, that's interesting to learn, just not so relevant to me as I never have laptops with working batteries 😁

This seems like a gap in FreeDOS then - perhaps if you report that you have a machine where FDAPM can't be used, someone will update it eventually.

Alas, "fdapm info" just reports that there's no APM info. 🙁

doshea wrote on 2024-09-21, 02:25:

Thanks, that's interesting to learn, just not so relevant to me as I never have laptops with working batteries 😁

Fortunately, this laptop (palmtop, really) battery was easy to repair. Just crack open the battery pack and replace the two 18650 cells.