Nothing Lasts Forever (why suffer?)
Rechargeable batteries just don't last forever - even good ones. I think it's a conspiracy by the physicists of the world who just need to tweak some equation somewhere for all of us to enjoy unlimited battery life. For sure Nobel Prize to whomever does this. Until then, we must replace batteries from time to time.
A lot better than the fan replacement I tried last week (I ordered the wrong fan, but ifixit is taking care of rectifying that snafu).
I put up with this dying battery far too long, and lost data when the old battery caused the system to crash instead of sleeping the system.