Originally Posted by sirmaru
To really run a valid comparison, one would have to record reading session times in an Excel spreadsheet for both the PW and KK. Otherwise, one really doesn't know.
I ran it for one battery cycle for the PW and got 10 hours and 29 minutes running the battery down to near empty. I've never taken the time to run it for my KK.
For my KF1G it averaged about 5 hours and 13 minutes and for my KFHD7-32 it averages about 5 hours and 39 minutes running it down to about 19% using GSam Battery Monitor for precise measurements by recording Screen Time right before I start a Full Charge.
Just reading for long stretches will NOT take an accurate measurement unless the default 5 minute shut down is changed to Never shut down.
The PW light does shut down when the standard magnetic cover is closed.
Remember, the PW battery meter will not be accurate until taken to a zero charge at least once and then given an overnight charge. The zero charge (really at 15%) is indicated by a screen showing a large battery icon, a wire and a lightning bolt to indicate power is required.
You do not need to carry out this test to know that the battery on PW is worse than the KK. However a good point about completely draining battery and doing a full cycle charge. I had the same problem on my iPhone 5. I'll have to try it on the PW.