Questions about Anker PowerCore III

Since I gave them away to South Africa I can't measure them. But I think the length of just under 15 cm should be right

No, unfortunately it didn't work for me.

when loading or when pressing the button

No, the power bank can only be used wired.

Anker hat extra einen low power mode (Trickle Charging Mode) für solche Geräte: https://support.anker.com/s/article/What-is-Trickle-Charging-Mode Trickle charge mode is designed for use with devices that have a low power draw like Anker earbuds essentially. When you enable trickle charge mode the power bank knows to output a low charge from the port (for example under 0.5 amp) to the connected device to prevent the PowerCore from turning off. The minimum current requirement (the lowest amount of power a device needs to draw from the battery so that it doesn’t turn off) for our battery is about 30mA to 90mA. When the required input of low-powered devices is less than the battery's minimum current requirement, there will be no current to charge the devices. To activate it, press the button twice. The LED indicator will turn green, indicating that the trickle charging mode is on. It will turn off 2 hours later when unused.

No, only USB (5V).