What is the USB voltage timer?

Question

USB

Good afternoon. There is a device that has a built-in battery and, as usual, is charged from usb. The problem is that when an external battery is connected (which is activated when a load appears), the device, when the built-in battery is fully charged, ceases to act as a load (I don’t know what it’s called, something like usb blocking when it reaches full charge to protect against recharging) and after some idle time (about 5 seconds) the external battery turns off and waits for the next energy request (load connection), which does not occur until it (load) is reconnected.
So, are there USB voltage supply timers? To be included in the gap between the device and the battery and, for example, once a day it automatically starts and, acting as a newly connected load, passes voltage to the device through itself.