Eli5: Where does the rest of the electricity from my power bank go?

Question

If I fall asleep while my phone is plugged into the mobile power bank, the phone will be at 100% battery in the morning but the power bank will be empty.

If I unplug the phone as soon as it reaches 100% the power bank will have enough battery left for 3 more charges.

Where does the rest of the electricity go??

In: 0

Answer 1

This implies that you either have a dodgy phone or a dodgy power bank. I’d try the same arrangement with another phone to see if it still drains.