How GaN chargers work

They're smaller, lighter and quicker, but what's their secret?

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GaN chargers are cool. Not in the informal statement of approval sense, but they’re quite literally cool. By using gallium nitride (GaN for short) instead of silicon for their transformers, GaN chargers generate less heat when charging. This means the components can be packed closer together in the unit, making them smaller and easier to carry around. And with less energy being lost to heat, the power is more efficiently transferred into what it is you’re charging. They can carry a greater voltage than silicon too. The end result? Faster charging.

Gallium nitride itself isn’t a new discovery. It’s been used in blue light-emitting diodes (LEDs) since the Nineties, and later provided the breakthrough that made the first white LEDs possible. It’s also used for solar cell arrays on satellites, and the blue lasers used in Blu-ray players. But it’s the potential of gallium nitride semiconductors in chargers and power supply units we’re interested in here, and in this area, it’s fairly new.

Back in the day, a charger was a very simple device. It transferred mains power to a battery-powered device, constantly charging the battery. Yet as mobile technology advanced, it was realised that this was a very poor way of powering up. Receiving a constant power supply in this way, even when the battery was full, caused degradation over time. A degraded battery holds less power, meaning you got shorter and shorter use from your mobile device before it needed charging again.