How do two batteries discharge on DUO eBikes?

When two batteries are connected to a DUO eBike and considering that both the batteries are on the following would occur;

Case 1: When both batteries are at 100% OR the same level -
The Dualizer would draw power from one of the two batteries (usually primary battery) and once the voltage drops slightly in the first battery, the Dualizer switches to the second battery (Range Extender).

As the voltage in the Range Extender drops slightly lower than the Primary Battery the Dualizer again switches to the Primary battery. This continues until both batteries are discharged to their cut-off voltage.

Essentially, the Dualizer keeps switching between the two batteries and thus discharges them together.

Case 2: When two batteries are at unequal levels-  
The Dualizer would first draw power from the battery that is at a higher voltage and keeps getting power from this battery till its voltage reduces slightly than the other battery. After this, the Dualizer switches to the other battery and the switching between the two batteries continue as explained above in Condition #1.