Thanks everyone!! I'll be making me a nice spreadsheet. But even without it I can see my battery definitely isn't doing what it should :S
Oh, and, I just looked at my Glo to see how much it had dropped during the night. 12 hours ago it was at 40%... Now it's the black screen telling me to charge – no way to know how long ago it ran out of juice. So, that gives me 6 days in sleep mode, no wifi, no nothing.
Now I have to choose between contacting the Dutch mail order company I bought it from or go directly to Kobo...