Since you are using migration assistant from an old 2011 macbook, you might want to reset your power management settings, (older macbook that come with spinning drive has different standby/sleep/hibernation value/settings)Thanks ill check that out. But i though those things were not needed anymore if the macbook had the newest boot rom from big sur, which i have.
or does it only work if i use opencore and upgrade to a newer MacOS?
Also it says this on Github.
"Note that MacBookPro11,1 and MacBookAir6,2 are not compatible with 3rd-party NVMe SSDs in lower power modes. Owners of these two models are not recommended to install ssdpmEnabler as it will result in crash."
open terminal,
run this command :
sudo pmset restoredefaults
enter
then run this command :
sudo pmset -a powernap 0 standbydelaylow 1500 standbydelayhigh 1500
enter again
that's it,
bar any hardware issue, you should experience no battery drain overnight
also, reset your SMC won't hurt either. I assume you unplug your battery during ssd installation, and any battery re-placement/installation should be accompanied by SMC reset.