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Every device---smartphone, tablet, or laptop---seems to come with its own charger. But do you really need all these different cables and charging blocks? Can you re-use the same charger for multiple devices?

While this used to be a far more complex topic, standards have (finally) started to come into play that make it much easier to manage. Let's talk about it.

The Different Types of Chargers

While chargers are becoming more standardized over time, there are still a variety of different charger types in wide use:

  • Laptop Chargers: Unfortunately, there's still no standard type of charger for laptops. You'll want to get a charger designed specifically for your laptop. Connectors aren't standardized, so you probably won't be able to accidentally plug the wrong charger into your laptop. Though, with the introduction of USB Type-C (outlined below), this is starting to change, albeit slowly.
  • Apple's Lightning Connector: Apple has uses the Lightning connector, introduced in 2012, for their mobile devices. All new iOS Devices use the Lightning connector and can be connected to any Lightning charger certified or developed by Apple. Older devices use Apple's 30-pin dock connector. Apple makes a connector that allows you to connect new devices with a Lightning connector to older charges with a 30-pin dock connector, if you really want to do this.
  • Micro-USB Chargers: This was the "standard" (so to speak) for years, and many smartphones and tablets use standard Micro-USB connectors. These replaced the Mini-USB connectors that came before them, and the proprietary chargers that old cell phones used before that. To comply with the European Union's directives on a common type of charger for smartphones, Apple offers a Lightning-to-Micro-USB adapter.
  • USB Type-C: This is the newest standard to hit the scene, and essentially the evolution of Micro-USB. USB Type-C (often just referred to as "USB-C") is a reversible connector with a much higher data throughput and capable charging rate. It has effectively taken the place of Micro-USB on most new devices outside of Apple's iDevices, and is even starting to show up as a standard charging solution on many laptops.

Chances are you have devices that use at least a couple of these. But you already know which devices use which chargers---so you really want to know if you can mix and match power bricks. That answer is...well, maybe.

Understanding Volts, Amps, and Watts

To understand charger compatibility, you first need to understand how they work---at least on a rudimentary level.

There are a variety of ways to break down volts, amps, and watts, but I'll use the most common metaphor: think of it like water flowing through a pipe. In that case:

  • Voltage (V) is the water pressure.
  • Amperage (A) is the volume of water flowing through the pipe.
  • Wattage (W) is the rate of water output, which is found by multiplying the voltage by the amperage.

Pretty simple, right? Back in the day, most mobile phone chargers came in two varieties: 5V/1A and 5V/2.1A. The smaller chargers were built for smartphones, and the larger for tablets. Any phone charger could be used with any phone, and most tablet chargers would work on any tablet. Pretty simple stuff. All Micro-USB chargers were rated for 5V, so you never really had to worry about accidentally plugging your phone into a charger with too high of a voltage.

But now, things are much more complicated. With larger device batteries, new charging technology like Qualcomm's Quick Charge, and formats like USB-C that allow for better charging throughput, chargers are more complex than ever. If interested, you can find any charger's output information written in tiny text somewhere on the charger itself.

Now, while we don't need to over-complicate the discussion and break down every device charger out there, this basic knowledge is a bit of a necessity.

Understanding How Charging Works

So let's say your phone shipped with a 5V/1A charger. This is what we'd generally think of as a "slow" charger, since the majority of modern chargers are much faster now.

Does that mean you can't use a 5V/2.1A charger, or even a 9V/2A charger (in the case of USB-C)? Not at all. In fact, a higher amperage charger will likely charge your phone even faster, and it can do so safely. Basically, all modern batteries are built with with a chip that regulates the input---they will allow what they can handle. This is actually a two-way street, because the chargers also support these "smart" features, which is why you should always buy high-quality, name brand chargers instead of cheap knockoffs.

Note: Charging bricks that support more than 5V will be USB-C from end-to-end, making it impossible to accidentally use a Micro-USB or Lightning cable.

This is why you can use a Quick Charger on older smartphones that don't support Quick Charging technology---both the charger and the battery have the necessary safeguards in place to keep anything bad from happening. The phone will just charge at the normal speed its designed for.

Speaking of Quick Charging, let's touch on that briefly. First off, there are several quick charging methods form a variety of different manufacturers and they are not cross-compatible. That means just because your device supports some form of "quick charge" technology and your buddy's charger does too, you can't automatically guarantee you'll get a faster charge. If they're not using the same quick charge technology, it will still charge you phone---it'll just do it a bit slower. (This will change soon, but for now, we're stuck with multiple standards.)

So, Can Any Charger Be Used with Any Device?

The short answer is: most likely, though you'll have varying results.

For example, let's say you're using an old 5V/1A charger on a brand-spanking-new smartphone. You're going to have less than stellar results there, because it's going to charge the device much more slowly than the charger that came with the phone. Most modern smartphones can accept much faster chargers.

Laptops are often a different story. If it has a proprietary charging port, I wouldn't use anything outside of the stock charger (not that you could anyway, since it's proprietary). But since USB-C is the first USB technology that allows high enough throughput to charge laptop batteries, you may have a new laptop that charges through USB instead of a proprietary power cable. So with that in mind, could you use your smartphone charger on your laptop? What about your laptop charger on your smartphone?

Mostly, the answer here is going to be "yes." A smartphone charger is going to be very low power for a laptop, but it may be able to charge it while the laptop is in standby mode, though you'll likely have to test this to find out. If it doesn't work, it won't harm your device.

On the other hand, you can definitely use your USB-C laptop charger to juice up your smartphone. Again, those safeguards we talked about earlier will allow the charger and battery to talk with each other and automatically default to the fastest allowed charging speed. It's very cool.

For example, I almost always charge my ASUS Chromebook C302 with my Pixel 2 XL's charger when I'm at home, and I've used my C302's charger on my Pixel multiple times when I'm out. I leave the C302 charger in my bag all the time and the stock Pixel charger plugged up, so it works out well.