Same issue here, 8 months only… Lasts 50 minutes exact.
It seems like when the ear buds are drained, the voltage is very low, damaging the battery, a battery replacement is not really cost effective, not to mention difficult.
Try charging it as soon as its around 20% if you want it to last for years. Very disappointing.
These cost ~4 times more than my 6 year old JLABs that still work, they went from 8 hours to around 5 hours with ANC…
Edit: I’ll report back if my modification works with a new battery, it consists of having an inline diode to prevent low voltage damage by having an early cutoff.