Travelling soon, pulled out my 2012 macbook to make sure its usable, but the replacement battery was completely dead, even after a full day of leaving it plugged in. Luckily when I bought the battery kit from ifixit a few years ago they had to send me two due to some problem with the glue solvents. So today I've installed the replacement-replacement battery, and my 13 year old laptop continues to remain operational and useful
For the curious, it runs Arch Linux nowadays, which even supports switching between the 'integrated' Intel GPU and the more powerful and energy thirsty nvidia onboard GPU
