Same here Model: MBP 2015 13" What: battery died after installing Big Sir, service recommended. Unplugging shuts off computer. Returning to older OS doesn't fix it. Did anyone try replacing the battery and keeping it on Catalina? I don't want to waste money on a battery if the problem might lie in the circuitry or if it will just die again. Already tried SMC and PRAM and all the other standard fixes of course.

Update on my previous post (one above) Got a (fake) battery and installed it, works like a charm so far. I did use an OEM charger before though, which might've caused the defect. Switched over to an official charger just to be sure. Did anyone else here use a fake charger, might be the cause of this?