The SyncBac PRO has its own 12 hour internal battery and so will not drain the GoPro’s power. This also means that it cannot be used to power the GoPro. However if you connect the SyncBac PRO to a power source while they are connected, they will charge simultaneously (Hero 4 and HERO7 Black only). Learn more about this here.
Using the SyncBac PRO with the BLINK Hub app can also be used to help conserve the GoPro’s battery life. When using a :pulse as the master unit you can use the BLINK Hub app to turn the GoPro’s on and off when they are connected with a SyncBac PRO - meaning you can save power when they're not in use