I've discovered the phone has a doze function, though I don't yet know the parameters. However, some amount of time of inactivity with the phone fully charged will cause the external battery to turn itself off. There are two other tests I want to run. One is to track SOT. For example, it has now been over 36 hours since I charged things up and the external battery is still above 50%. However, that includes time I'm not using the phone like when I'm sleeping. The second is to start out with he external battery off, run the phone battery down and then see how long the recharge takes from just the battery pack. I'll come back and report what I find.