Ifixit Battery capacity halved in less than one year

Hi All,

I’m wondering if anyone may understand what’s happening here.

This is my third go at a battery from IFixit for this laptop, and I thought 3rd time the charm since it worked finally! Held a charge, wouldn’t cause the laptop to randomly restart, etc. It was all going well until I saw the other day the “service battery” alert in the menu bar.

ran coconut battery and attached screen shot. Design capacity is suddenly now at 51% even though the battery made date is 2020-10-19!!!!

WHAT?!?!?!

Macbook Pro 15” Mid-2012. Battery installed last year, did battery calibration at the time, did the whole reset pram, smc, etc. And like I said, worked (Not as long as I’d want, but length of time was realistic) fine up until just a few days ago.