How do GaN chargers work, and who makes them?

What a charger does is rather implicit in the name; it provides charge to a device that needs it. All simple so far, right, we’re talking those little blocks that you plug into the wall and then use a cable to connect up to your gadget whether it’s a smartphone, tablet, laptop, portable games console or countless other devices.

Where it gets more complex is if you bust open that charger and have a look inside – which, we hasten to add, you absolutely should not do out of idle curiosity. Partly because you’ll almost certainly break it, which would be a waste, but also because even if you do get it back together again, there’s significant electrical risks involved.

Still, if you were to do so, you’d find an array of tightly-packed wiring built (typically) around a group of silicon circuits that at some level regulates the power coming from your wall switch through the charger and then out to either an integrated cable or a socket. Usually these days that will be a USB socket, either USB type A or USB type C for most chargers designed to deal with mobile gadgets such as smartphones.

The critical part there is the use of silicon circuitry, built around the same essential physical principles as the silicon circuitry that runs so much modern technology. 

Where a GaN charger differs is that it doesn’t use silicon, but instead Gallium Nitride for those essential connection components. Gallium Nitride compounds and semiconductors use very small hexagonal crystalline structures – strictly speaking they’re wurtzite crystal structures – that give GaN chargers some very specific advantages over traditional chargers.

At a very basic level, you could argue “not much”, because the core mission of providing power through a handy plug doesn’t differ just because you’re using a GaN charger. Plug it into the wall, plug it into your device, no change there.

However, the nature of the crystal structures in a GaN charger does give them some particular advantages over traditional charger technologies. The critical one here is size, because it’s possible to safely and efficiently pack in circuitry in arrangements that allow for a higher power throughput relative to the size of the charger than you would see in a standard charger.

If you’ve ever had one of those laptops with a charger that seems to weigh as much as the laptop itself and is about half the size, you’ll be aware that some higher power chargers can be on the large side. GaN chargers can pull through as much power safely as those larger sized devices in a plug that’s considerably smaller and lighter, making them much more portable. The nature of those crystal arrays means that a comparable GaN charger outputs less heat than a standard charger, which can also have an impact on overall charger efficiency as well.

Many GaN chargers also comply with the PD (Power Delivery) standard, which means as long as they’re rated for the right level of power output, a single GaN charger could power not only your phone or your headphones, but also your tablet or laptop.

One important caveat to throw into the GaN charger debate however, is to point out that a GaN charger won’t (by itself) charge your device “faster” to speak of. Charging speeds are a joint function of the power output of the charger but also the level of power input that your device can actually take. Let’s give this some practical numbers to illustrate.

Say you’ve got an Apple iPhone 15. Apple’s official specifications for the iPhone 15 calls for a 20W or higher charger to get optimal charging speeds, with most analysis suggesting that it’ll top out around 27W in terms of real world charging. That’s not an official Apple figure – it just simply never states it – but let’s go with it as our figure here.

If you’ve got an existing 45W PD charger, it’ll regulate the charging up to that 27W figure, no faster, but whether it’s silicon, GaN or made out of fairy bread – presuming that were feasible – wouldn’t actually matter. The charging rate would be the same, because it’s more controlled by the phone in this scenario, though we strongly suspect the fairy bread would catch fire in this hypothetical example.

Where you would see an improvement in charging speeds is if you were still relying on an older plug adapter capable, of 5-10W, for example. There a GaN charger could ramp up to that 27W (theoretical) speed and power up your phone considerably faster.