Why is the battery in series with the battery pack?
The parallel connection is rarely used because the battery voltage can not be absolutely equal to bring the battery pack from the discharge problem.
The battery is connected in parallel to form the battery pack in order to increase the current.
The battery in series to form the purpose of the battery is to increase the voltage, such as a battery 1.5v need 6v voltage, in series 4 batteries in series.
