Our Macbook Pro runs at 1% of normal speed with a completely dead battery. A nearly dead battery makes it run at normal speed. We do not use the battery as a battery.
Ours is an A1286 from "2011 to mid 2012" with battery labelled A1382, but the battery for the A1286 from 2009-mid 2010 may also fit (A1321). The writing is black on black.
A smaller battery might also work if it has the same connector, but I presume Apple set things up to make that impossible.
Apple laptops with low batteries do not retain time and date either - no RTC battery.
Still need the battery on April 14, 2022.