battery communication w/o communicating inverter

[karlsolar]

My setup:  outback radian inverter, no solar CC yet, AC coupling being set up now, 2 MN powerflo 16 batteries, commmunication connected to each other and solar assistant. 
when the BMS power button is pushed on the "master" battery, it doesn't start up the second battery.  the communication to solar assistant seems ok, but I don't know if the second battery not starting up is indication of a problem, or if it will only start if plugged into the MN AIO. 

   I've charged the batteries off the grid, and run some odds and ends.  the location for it's permanent location is not ready yet, so it's on a cart.  just making sure things work properly before the permanent home is ready.

thanks
karl