I believe I am unable to configure MacBook Pro 2015 model to standby immediately, does anyone have the magic incantations (pmset)?

Question

I have an early 2015 model MacBook Pro and I notice that if I charge the battery to 100%, disconnect the power adapter and then close the lid, overnight it will use some of the battery, as though the unit is sleeping and not in standby.

I would very much like the MacBook to immediately dump memory to disk and turn itself completely off, whenever I close the lid.

I have tinkered with the pmset commands earlier, before Big Sur was released but I believe the addition of the "autopoweroff" setting has muddled the waters, and my tinkering + the changes introduced may have generated a configuration that isn't correct.

This is the output of pmset -g on my MacBook right now:

System-wide power settings:
Currently in use:
 lidwake              1
 autopoweroff         1
 standbydelayhigh     86400
 autopoweroffdelay    28800
 proximitywake        0
 standby              1
 standbydelaylow      10800
 ttyskeepawake        1
 highstandbythreshold 50
 powernap             0
 gpuswitch            2
 hibernatefile        /var/vm/sleepimage
 hibernatemode        25
 displaysleep         2
 sleep                10
 tcpkeepalive         1
 halfdim              1
 acwake               0
 disksleep            10

I have two questions:

1. How can I verify that standby is properly configured?

   I read on one page that if I close the lid, let it standby, and then open the lid and turn it on I should have a progress bar. If I do, it was in standby mode. This progress bar does not appear.

2. If the above configuration is not correct for my goal, which is "dump memory to disk and turn off power immediately when I close the lid", does anyone know the correct pmset configuration I would need?

Note that this progress bar does not appear even overnight, which leads me to believe the MacBook isn't actually going to standby at all, instead just going to sleep mode and sitting there until battery drains out.

Answer 1

The man page for pmset provides all the relevant information. Notably:

hibernatemode supports values of 0, 3, or 25. Whether or not a hibernation image gets written is also dependent on
     the values of standby and autopoweroff

hibernatemode = 25 is only settable via pmset. The system will store a copy of memory to persistent storage (the
     disk), and will remove power to memory. The system will restore from disk image. If you want "hibernation" - slower
     sleeps, slower wakes, and better battery life, you should use this setting.

Also note from the man page that standbydelayhigh and standbydelaylow specify the delay, in seconds, before writing the hibernation image to disk and powering off memory for Standby. Your values are 24 and 3 hours respectively.

autopoweroffdelay is also a large value, in seconds.

However, it's possible that an active process could be preventing sleep. For instance, here's the relevant output of pmset -g in my case:

 sleep                1 (sleep prevented by backupd-helper, sharingd, backupd, coreaudiod)

.
It's also possible that an old battery, reaching the end of its life, may not be reporting reliably, or not able to manage power optimally.