[Quoth]

I find none of my Kobos reliably display charge %, on many FW, while asleep. They update when awake. This makes sense otherwise the ereader would either not really be asleep or need a Hardware timer interrupt to wake it occasionally. I remember this being discussed in context of a "sleep screen clock/calendar", which really is a oxymoron given that updates to screen need cpu awake and it's one of the more power hungry activities. Obviously if there was a HW clock tick that only momentarily woke the CPU while external PSU detected on USB then more accurate sleep screen % charge and clock/calendar (with maybe only minutes) would be possible. I note on one of my Android devices if the time/date is wrong I can go to settings and change it but the Home Screen display shows the old time and date till the next minute change occurs!