This recently started happening to me. The front auxiliary power outlet in the front ash try works fine. The 2 rear outlets are unable to charge my phone (Samsung S7) for more than a few seconds. My battery is new.

Is my alternator on the way out?

 

Sounds like a wiring issue at either the outlets or your charger / cable. I doubt you'd notice your alternator going out from plugging in a 5 watt item especially since the front one works just fine. Most Autozones / NAPAs of this world will check your battery and alternator for free if you'd like to know for sure.

 

Turns out you were right. Swapped out the charger for a new one and no issues like before. Thanks for your help.

 

You're welcome! I just moved and have been doing a lot of little electrical projects, lol