flasher is claiming an USB interface and therefore need to be run with root rights.
Please try either logged in as root
'flasher -i'
or
'sudo flasher -i'.

I would like you to test above command to check whether battery really gets loaded with 'flasher -i'. Keep it connected for at least 30 minutes and disconnect/start up.
If that does not work you still may try above, but I would use
'flasher -f -F firmware.bin --flash-only=kernel'