My dad has a 2015 Altima. I don't know if it has a USB or a Cigar Lighter/power port, as they only come as an option, at any rate, even if he has one, it is only powered ON while the engine is running. With these new push button to start cars, there is no Accessory ON switch.
So I ordered a Power port that I'll install somewhere into his dash or console that will be always hot. It has a 12V cigar type socket, and 2 USB outputs, one 1.0A, the other a iphone compatible 2.1A.
The installation will be more of a gift that the gift itself.
When he lost power for a few days due to superstorm Sandy, he had an older phone that didn't hold a charge long, and he had to recharge it each day. No power... no charge! No communication. So at least with this he will be able to charge his phone from his car without running it.
Dad's Gift