if its a old school orion amp . i would say yes , it would be ok to run it a 16 volts.
i have a orion hottsetup manual and a few precision power manuals that all say the supply voltage can be from 10.5 to 16 volts....that amp should love 16 volts....
they are beast at 16v's...i remember them being used back in 0-300 usaci super stock..i'm getting rid of my Batcap 8400 16v batteries if intrested ...since I'm getting out of competition....