Lenovo ThinkPad x1 Carbon 8th gen charging problems

[titania177]

Hello,
I'd really appreciate any help here. I bought the Lenovo ThinkPad x1 Carbon 8th gen in July 2020 and suddenly the battery refuses to charge. It's on 0%. The laptop works fine with AC power plugged in. I wonder if this problem was caused by a USB-C - Ethernet adaptor I started using a few months ago, which in some way "confused" the USB-C ports, since they were now being used for something other than charging. I stopped using the adaptor a month ago but haven't been able to sort out this problem. I've tried the fix of going into the BIOS and disabling the battery several times, it doesn't work. I want to update the firmware, and have installed fwupd, but when I try and get the update, this is the output, even though I have AC power plugged in.

Devices with no available firmware updates:
• Integrated Camera
• UEFI Device Firmware
Devices not currently updatable:
• Embedded Controller — Cannot install update when system battery is not at least 25%
• Intel Management Engine — Cannot install update when system battery is not at least 25%
• MZVLB256HBHQ-000L7 — Cannot install update when system battery is not at least 25%
• System Firmware — Cannot install update when system battery is not at least 25%
• Thunderbolt host controller — Cannot install update when system battery is not at least 25%
• UEFI dbx — Cannot install update when system battery is not at least 25%
• Unifying Receiver — Cannot install update when system battery is not at least 25%
No updates available


Does anyone know of a fix for getting around this requirement of having 25% battery power to install the firmware upgrade that would enable me to charge the battery?!
Thanks so much in advance.