This was originally a huge problem for the cell phone industry, such that it was common for people to have drawers full of outdated wall warts and 12V car adapters. That all changed when manufacturers adopted 12V USB adapters as the de facto standard. While there are still limitations, most mobile devices today can be charged with a 12V USB adapter.
12V USB Adapters, 12V Sockets, and Accessory Sockets
USB is nearly universal, but 12V USB adapters rely on another ubiquitous technology to work: the 12V accessory socket. If you’ve never used a 12V USB adapter, you may be wondering if you can plug one into a cigarette lighter, or if you need a dedicated accessory socket. The answer is it does not matter. The difference between accessory sockets and cigarette lighters is just that you can’t plug a cigarette lighter into an accessory socket. As long as the socket itself isn’t damaged in some way, you can use your 12V USB adapter in either one.
Identifying the Right USB Charger Connector
Some 12V USB adapters include a built-in USB cable. If you want this type of adapter, then you need to choose the right type of connector. Look at the chart above and match the type of connection on your phone to the one pictured. Universal USB chargers can be used with any high-quality USB cable. When you purchase a universal 12V USB adapter, you will find it has a standard USB type A socket, which will look like the socket pictured in the top left corner of the illustration. If you buy a universal 12V USB adapter, you will also need to buy a compatible cable. Look for a cable that has a USB type A connector on one end. (That type is pictured in the top left of the above illustration.) The other end should match the charging socket on your phone, and will typically look like the USB-C, USB mini, or USB micro connectors pictured above.
Apple and Amperage
While some devices require more amperage than others to charge and operate with a 12V USB adapter, Apple devices work differently. They rely on a different method to determine compatibility with a high-amperage “charging port” or 12V USB car adapter. If you have an Apple device that you want to use with a 12V USB adapter, then you need to look for one that’s specifically marketed for Apple devices. While you can find USB car adapters that are specifically designed for Apple, there are also adapters that have two USB ports—one for Apple and one for Android devices. If you use a mix of Apple and other devices, then one of these multi-purpose 12V USB adapters is the right choice.
More Than a Common Plug Type
Whether you’re looking at standard USB, Mini USB, or micro USB, the standard specifies the same basic terminal connections. You can still use an adapter to go from micro USB to mini USB, or vice versa. However, the USB standard conveys another advantage that helps explain why USB made its way into our cars: standardized voltage outputs. Since USB connections put out 5v DC power, devices that use this type of adapter are all designed to run on that voltage input. Of course, not every device manufacturer plays by the same rules, which is why it’s important to consider the details outlined in this guide.