In today's day and age, it's easy to find in-car phone chargers that allow you to charge your phone while you're driving. But these products can be temperamental, and they can also drain your car battery! So, you might want to consider taking a power bank, too. All you have to do is charge them up before you embark on your road trip, and you'll be able to utilise some extra charge with ease.
These power banks are also pretty handy when you're not on a road trip, too. You can use them on trains, buses, and even use them when you're at work.