With the removal of the 'ectool' package perhaps it's time to remove/retire 'battery_firmware' from the crosh script to avoid any confusion when errors are displayed.
battery_firmware <info|check|update>
info : Query battery info.
check : Check whether the AC adapter is connected.
Also check whether the battery firmware is the latest.
update : Trigger battery firmware update.
When I attempt to run battery_firmware with any option it fails, see below -
crosh> battery_firmware info
Target program '/usr/sbin/ectool' is not accessible.
crosh> battery_firmware check
Target program '/usr/sbin/ec_sb_firmware_update' is not accessible.
crosh> battery_firmware update
================================================================================
Battery firmware update is in progress.
================================================================================
Please DO NOT remove the power adapter cable, otherwise the update will fail.
To recover from a failed battery firmware update,
please plug in the power adapter cable, reboot and run this command again.
================================================================================
Target program '/usr/sbin/ec_sb_firmware_update' is not accessible.
I confess I don't know how these things are handled internally so maybe it's already part of the plan.
Thanx for your consideration,
DennisL