You can also close the lid and trust it to stay off and open it up even a week later and resume at the same place you left off with very little battery usage. How no one else can figure out how to do this in almost 15 years or more is beyond me.
Something something windows something something shitty power management.
Try it for yourself and see if that makes a difference. It worked for me!
I remember at some point dell had a warning to not sleep your laptop and put it in a bag, as it can actually cook the lcd panel!