PowerCore 20100, iPhone 7, continuous charging for days, what to expect?

I use an iPhone 7 app as a GPS for ultra-distance cycling. (iOS 12.3.1). I plug the phone into the PowerCore via an Apple cable: it charges to 100%, then stops charging. Fine. The iPhone’s charge level drops pretty quickly with the GPS active, the screen on and connected to, or searching for, the cellular network. I can improve this considerably with screen off until needed and with airplane mode, but sometimes a route is complex and continuous GPS guidance is required.
I think I have seen that when the iPhone’s charge level drops to some low value (<20%), charging restarts automatically, without my doing anything. Maybe I imagined it. Recently, however, I couldn’t get charging to restart even by pressing the button on the PowerCore. I got it to go by moving the cable from one PowerCore output port to the other. This seems strange. Was it a coincidence? When it isn’t working I need to know how to get it working with confidence.

  1. The PowerCore 20100’s capacity, size and weight are superb for my application.
  2. I would like a clear description of what to expect when continuously charging an iPhone 7.
  3. I would like to know what the button on the PowerCore does.
  4. Are there multiple button actions?
    • Double-click?
    • Hold for N seconds?

I would try using a different cable first before you crazy teying to figure out why it is doing wjat it does

As @Tank said, try a different cable. If that doesn’t solve your problem, then email Anker at support@anker.com for other troubleshooting suggestions.