[icallaci]

It's not really new info, since I didn't start measuring the battery loss until after the first time it happened. When I got the message to "recharge now or else," I suspected the sleep cover problem, so I removed the sleep cover, charged the reader to 100%, left it overnight, and saw a ~25% loss the next morning. I charged it up to 100% again, left it for several hours while I was out and about, and noted the battery loss when I checked it again. I checked it at least once a day, but the percentage varied with the amount of time elapsed--that's why it ranged from 60%-80%. If I had been troubleshooting at work, I would have noted all the times and percentages more rigorously, but it's the holiday season and I'm busy, so I didn't. Anyway, after I reverted back to 2.8.1b and then upgraded directly to 3.1.1, the problem went away. I have no idea why, and I know I did not check out every possibility (for example, I had reloaded all my books onto a new SD card under 3.0.0), but I just didn't feel like spending any more time on it if I didn't have to. It's working now, and I am glad.