Fire Kindle Power

I've read many post trying to understand the power requirements to power 2 Fire 8 tablets with alarm and strobe. From what I read, the 6 or the 12 board requires 12 volt to power it up and has an output of 5v.

My question can you power 2 Fire tablets off the Aux power and still have enough to power the Alarm/ strobe, if not, what a better option. Thanks.