Having several adapters you can work with several batteries at the same time. Just connect them to PC and run BE2Works. You will see the list of adapter and can choose what adapter to assign to current copy of the software.
Then click the software icon again and assign another adapter to another copy of the software.
And so on. Number of adapter and the software copies is unlimited.
It's very useful for example if you want to analyze one battery an to work with another not waiting for analyzing finish.