VCC: Battery positive terminal, here there are two sets of VCC and GND is to increase the current and reduce the resistance.
Middle: To balance the voltage between the two cells and thus protect the battery.
GND: Negative battery terminal.
This is a custom battery pack made by SunFounder consisting of two 18650 batteries with a capacity of 2000mAh. The connector is PH2.0-5P, which can be charged directly after being inserted into the Robot HAT.
Battery charge: 5V/2A
Battery output: 5V/3A
Battery capacity: 3.7V 2000mAh x 2
Battery life: <90min
Battery charge time: >130min
Connector: PH2.0, 5P