PRS-650 Battery Drain
I have this strange battery drain issue as well. I have a prs-650. This has happened several times already with my device. The most recent scenario is the following.
Charged to full on Friday
Read for 45 min on the commute home
Left in sleep mode and over the weekend the device automatically shut off
Monday morning, turned device on to read for 45 min during commute to work, battery indicator showed full bars
Monday evening, turned on from sleep mode to read for 45 min during commute home, battery showed 3/4 bars
Tuesday morning, turned on from sleep to read and battery indicator showed 1/4 bars
So the device was probably in use for a little over 2 hours and the device was at less than 25% battery. Like I said, this was not the only incident.