Review: External battery perfect fit for smartphones

External batteries all function the same. You charge them from a power source, and the internal batteries store the power to charge your phone when you're away from a plug.

Some batteries are small enough to slip into your pocket; others are large enough to keep you powered up for a week or more.

If you own a phone with wireless charging, the UnPlugged 10K is the perfect external battery for you. The big feature of the UnPlugged 10K is a wireless charging pad built into the battery.

As the name implies, the Unplugged 10K has a 10,000 milliamp-hour battery that can charge an iPhone 8 Plus almost four times. The UnPlugged 10K also has two USB ports, so you can charge three gadgets at a time — two wired and one wireless.

The UnPlugged 10K has a cool feature that lets you use it as a desktop charger. If you keep it plugged into a power outlet, you can set your phone on it, and it will charge the phone and keep the battery topped up.

The 10K is the largest battery in the UnPlugged line. There are several more inexpensive models with less battery capacity.

In the past, battery cases were a bit cumbersome to carry in a pocket, because they had to use the iPhone's charge/sync jack to transfer power to the phone.

The battery case charges two ways: through a USB-C port on top or wirelessly through the back of the case. So you can keep the iPhone X in the EasyAcc battery case and use your desktop wireless charger to keep both devices charged.

You can also use the battery case to charge other devices through the USB-C port.

The fact that the USB port is on top means the case leaves the Lightning port open on the bottom of the phone for transferring data or playing music.

The case is still a bit thick but fits much better in a pocket and gives a good amount of external protection.