140W or 65W: which GaN charger do you actually need?
Wattage has become a marketing number. Here is how to work out what your devices can actually draw, and why gallium nitride changed what fits in a bag.
Charger wattage has turned into a specification race. Most people do not need the biggest number, but plenty of people buy a charger too small to do the job they actually have.
What your devices can draw
- Phones: 20 to 45W. Almost nothing benefits beyond that.
- Tablets: 20 to 30W.
- Thin laptops (MacBook Air, most ultrabooks): 30 to 65W.
- Larger laptops (14 and 16 inch MacBook Pro, gaming laptops): 96 to 140W.
- Earbuds and watches: under 10W.
A charger negotiates down to whatever the device asks for. A 140W charger does not force 140W into a phone; it gives the phone the 25W it requests.
The arithmetic that matters
Add up what you want charging at the same time, not what you own.
- Phone plus earbuds → 30W is plenty
- Phone plus tablet → 45 to 65W
- Thin laptop plus phone → 65W works, 100W is comfortable
- Large laptop plus phone plus tablet → 140W
- Two laptops plus a family's phones → 200W
The common mistake is buying 65W for a desk running a 16-inch laptop and two phones. It works, but everything charges slowly, because the charger splits its budget.
Why gallium nitride changed the maths
Silicon wastes more energy as heat, and heat needs bulk to dissipate. That is why the old laptop brick was the size of a bar of soap.
GaN switches faster and leaks less at the same voltage. Less waste heat means smaller heatsinks, which is why a 140W four-port charger now fits in a jacket pocket. It also runs cooler, which is easier on the battery at the other end of the cable.
What to check before buying
- USB-C PD 3.0 support, not just "fast charging"
- How power splits across ports when several are in use, which good listings state
- A BIS mark, which is the difference between a tested power supply and an unknown one
- Interchangeable plugs if you travel
Our two
The JINX 140W has four ports and covers a laptop plus two devices at full speed. The 200W has six and is aimed at desks and households rather than individuals. Both ship with EU, USA and UK plugs, and both are BIS certified.
By JINX Team