I just returned from a business trip involving air travel and car rental. Something that disturbs me is the number of people who plug in their cell phones into public stations. You should Google “Juice Jacking”, it might change your attitude of using public charging stations.
You know, that port on your phone’s entry point into your personal life?
It’s possible for someone, somewhere, to infect your device with Malware.
Another good practice: Don’t connect your cell phone to your rental car. Connecting it (whether USB or WiFi) isn’t safe for obvious reasons. Also, depending on the car brand/model, you may load personal details into the car. I saw some details of one of the previous car drivers. I’m sure that’s different car to car.
I carry and use a power adapter for AC power and carry a cigarette lighter adapter for mobile use. You can buy them at any retail store for $5. Cheap insurance.