I try to keep it around 20 - 80 %, that’s 2 - 3 days. Fully charged, (by the way, there is more capacity beyond “100%”), 4 possibly even 5 if going to like 5%.
But I use it heavily.
Also, that flashlight at the back can actually drain it quite fast. Hell, if you have like 30% it can’t keep it on full power steadily, it starts flickering a bit. It gets completely disabled <20%. Earlier if you use it in the camera app. Ideally, if you want to use it combined with the camera you’ll have > 50%.
You may be able to charge your laptop from it if it supports 5V charging. It can supply 10W. To get some idea, my ThinkPad L390 yoga is currently consuming 3.73W as I am typing this.
But as I wrote, good luck charging it, though my unit may be defective. I don’t have another one to compare to.
I was doing best waking up at around 14 - 15 and going to sleep around 7 in the morning.