I got my ReMarkable last week, and I almost returned it immediately because I was getting astoundingly bad battery life (losing 5-10%/hour, dead in less than a day). I had disabled auto sleep, because I wanted to keep my notes in front of me and visible at all times while simultaneously working on the laptop. At some point it occurred to me that this might be the problem, and it clearly was... manually triggering the screen off when not actively using it, and leaving auto-sleep ON has given me more respectable battery life, but I'm also annoyed by having to constantly be hitting the power switch, especially because that goes against my understanding of e-ink – isn't the whole premise that it only uses power on refreshes? Why would there be significant battery drain if it's just sitting there on a page without actively being used?
The only thing I can think of is that somehow the wacom layer may be constantly "listening" for input when the screen is active...? Any thoughts/ideas? Still frustrated and considering if this is the right device for me if I can't leave the screen on for fear of draining the battery in a single day...
When the tablet goes to sleep, it shows a "sleeping" screen on the display. It sounds like you don't want that to happen.
In the Settings → Security screen is a setting called "Light sleep". I haven't used it, but from what I've read, if this is turned on, when the tablet goes to sleep after 20 minutes it will leave whatever document was on the screen, on the screen, rather than showing a "sleeping" screen.
Maybe this is what you're looking for?