Libra 2E bricked, any suggestions what to try?

[ams]

Something went wrong with an attempted firmware downgrade of my Libra 2.
Still started with manual reboot (long press of power switch for 20sec) but after showing home screen for 1-2sec it always switched to black screen with battery symbol and "please charge your reader". Charging didn't help, even over night. Manual factory reset (page button and power off for 20sec) did not work.
Opened it and installed new SD card with image I got via firmware request thread. After change of SD card, the reader first showed the screen in the attached image. Could do factory reset once but then the same issue: reader starts, shows screen for language selection for few seconds and back to "please charge your reader". I can do manual reboots but not a manual factory reset again, that only worked once. Manual reboot sometimes just stops (three dots screen frozen) if USB power cable is not connected. Battery is manufactured 06/2022 accoring to label so it would be strange if it actually died now in the middle of a firmware downgrade. It was actually fully charged during the downgrade attempt.
I wonder whether it is worth a try to replace the battery (if I can find one that fits)? Or is this likely some damage that cannot be fixed anymore?
Shouldn't the reader work even with a dead battery as long as the power cable is connected?

[leftright]

Copy the image to the old card.