A123 build question

I'm using a 610I Net charger and have built 2 5S1P a123 pacs. It has a a123 capability out of the box, its in the menu. Print the 2 page manual and read it, not sure its intuitive enough to get everything set right without it.

Once I got the balance taps sorted out, I found there was a right an wrong way to connect pac to the charger - connect the pac while everything is turned off, both power and balance wires. Once everything connected, then turn charger on, setup and charge/balance.

Supposedly, the built in balalncer is the same thging as the lba10 balancer. I know its wired the same way.

Once everything connected, then turn charger on, setup and charge/balance.

I must connect both lead (pwer and balancing) before to switch charger ON???????????

Why?????????