Installing a 14.4 volt head unit?

I have a no name head unit that is rated at 14.4 Volts? I can get the power light to come on but that is it. I don't understand why it is a 14.4 when cars have 12 volt batteries? Any ideas on what I need to do in order to get it to work? I have been told I need to use 2 batteries???
 
Thanks I'm clueless!

All audio equipment should be rated at 14.4V, something may be wrong with the headunit then.

Thanks for the reply! We just hooked it directly to the battery, is there something else we need to try?

Hooking it up directly to the battery can work sometimes but I have tried it that way before by just touching the wires to the battery and the unit not power up probably due to not having a steady power connection. If it is securely connected to the battery I would think it should work fine that way.

The batteries are 12.6 volts but when the truck is on and the alternator has kicked on... the batteries should read about 14ish volts.but also make sure the ground connection to the chassi is good as well as ur ground amp. 

Thanks! I'll try it again and see what happens. I know sometimes it takes more than just a simple hook up. I just wanted to make sure it worked before I installed everything. I'll keep trying!