Upgrading from Seatalk1 to Seatalk NG

I am replacing my chart plotters and radars and keeping my ST60 instruments that run on Seatalk1. I bought the converter (ST1 to STNG) and hooked everything up.

The Seatalk NG backbone kit comes with a cable to hook to 12v for power. I already have 12v powering my Seatalk1 - will that also power the Seatalk NG backbone or should I connect the NG power cable as well?

Thanks,

Ken