It is a special signal to help the charger determine the state of charge of the battery, to avoid overcharging. It may be a simple temperature sensor, or it may be more complicated.
It is a special signal to help the charger determine the state of charge of the battery, to avoid overcharging. It may be a simple temperature sensor, or it may be more complicated.
It is probably a data stream. Phone batteries are continually exchanging information with the phone, to keep track of its age/serial number/capacity/remaining.