so annoyed rn i put my Windows handheld to sleep by tapping the power button, and when I picked it up later it showed this:

Battery low
Connect the charger soon. The device will go
to sleep automatically at 2%.
Last full charge: 1 h 52 min ago
It lost 20% overnight. That makes it hard to rely on as a grab-and-go device. Is this normal for handhelds, or is something keeping it awake?
I bought a handheld specifically to be able to pick it up and play for ten minutes... right now I can't trust it to have any battery left when I need it.