I suspect that this battery has planned obsolescence. During the first half of the year of usage, the battery was at 100~101% health. Near one year usage the battery health suddenly went to 91%(may occasionally float to 95%).
System: AMD 7840U, with 61Wh battery (limited charging voltage 17.8V)
No BIOS update was done, the BIOS stays at 3.05
Arch Linux(6.13.6-arch1-1)
However, notice the “Desired Voltage” half a year ago.
Desired voltage 17800 mV
$ sudo ectool battery
Battery 0 info:
OEM name: NVT
Model number: FRANGWAT01
Chemistry : LION
Serial number: 0035
Design capacity: 3915 mAh
Last full charge: 3755 mAh
Design output voltage 15480 mV
Cycle count 48
Present voltage 16542 mV
Present current 3630 mA
Remaining capacity 620 mAh
Desired voltage 17800 mV
Desired current 3915 mA
Flags 0x0b AC_PRESENT BATT_PRESENT CHARGING
And here’s now
Desired voltage 17600 mV
$ sudo ectool battery
Battery 0 info:
OEM name: NVT
Model number: FRANGWAT01
Chemistry : LION
Serial number: 0035
Design capacity: 3915 mAh
Last full charge: 3558 mAh
Design output voltage 15480 mV
Cycle count 145
Present voltage 17416 mV
Present current 2450 mA
Remaining capacity 2562 mAh
Desired voltage 17600 mV
Desired current 2740 mA
Flags 0x0b AC_PRESENT BATT_PRESENT CHARGING
(ignore the 3915mA to 2740mA, the current reduces when charging past 4.15V/cell since the very beginning, i.e MCC-CV charging)
Since now the battery health is 91% and 55/61=0.9, I can safely assume that the battery has 0 wear. The 9% wear is due to the voltage being ARTIFICIALLY reduced from 17.8V to 17.6V
Any explanation of that? I appreciate that the battery is available and can be replaced easily, but blocking the original voltage and creates the illusion of battery degradation is, well, unethical and unsustainable.