Loaded that then it said the below (so apparently not dev.acpi_ibm
anymore, but I don't know what replaces it after Lenovo took over from
IBM).
root@microcosmos:~/freebsd.sys/etc # battery_ctrl.sh 50 70
sysctl: unknown oid 'dev.acpi_ibm.0.%location'
[: Unknown: unexpected operator
start threshold was set to : 50
[: Unknown: unexpected operator
stop threshold was set to : 70