Since my post #192 I have read 4 hours for a 10% drop (from 100%).
That is with no light and no Wi-Fi.
There device has had a full battery drain twice - one intentional and one not, and has hence been recharged from near empty three times.
Of course, with the rather erratic battery level reporting it's quite possible that it may plummet 10% during the next five minutes reading.
