I’m having a similar issue as yours and to this thread here: [SOLVED] Battery claiming drastic drop in health after updating to BIOS 3.03
I’ve only had my FW16 for about a month and my battery capacity hovers around 70% (60 Wh max/85 Wh design). I’ve tried defaulting BIOS settings, a mainboard reset, multiple charge/discharge calibration cycles, etc.
Mint 22, Ubuntu 24, and Fedora 42 upower all report the same degraded capacity number. Windows 11 powercfg /batteryreport does as well. Only 15 charging cycles on the battery according to Windows.
I have a support ticket that tier 1 escalated, but they did so over a week ago and I’ve heard nothing back since. I have requested an RMA on the battery a few times with decent evidence that it’s defective. So far that request in particular has been ignored.