Mine still goes down a bit even if in standby. Like overnight. But its not more than a couple of percentages, or maybe 3, depending. Wifi off.
But since I read a lot each day, I charge every other day anyway, or at most 2.5 days. I don't like going all the way down so technically I could probably go 3 days.
I been keeping wifi off, but I might turn it on just to see the difference. Although I keep my light low, 8-10 and have even turned it off in a bright room, one should be able to turn it up to whatever is comfortable. I do keep my bold at #3 and bookerly, which seems overall the darkest font on the serif ones. I can't read with san serif. But if someones eyes need 18 and it shouldn't totally empty a device in a day.
I gave my old PW1 to my husband and he has the light really high on it when it does read on it. Like 20 or so
. But he reads mostly with tablets so is used to have that light beam coming at him. One night, lights already out, he showed me something on his phone and it was like looking into the sun. OMG
I knew then that our eyes are way different from another.
I assume the restart and charge all night has been attempted? Check for indexing?