Chargers & Cables

What Is USB Power Delivery (PD) and Why It Matters

What Is USB Power Delivery (PD) and Why It Matters

USB Power Delivery, usually called PD, is the standard that lets a USB-C charger and a phone or laptop agree on how much power to send, up to 240 W. If a phone charges slowly on a charger rated for more watts, the charger, cable, or phone is missing PD support. A single 65 W PD charger plus a 100 W rated USB-C cable covers nearly every phone and most thin laptops.

How Power Delivery negotiates power

Before any real power flows, the charger and device exchange a short message over the USB-C connection and settle on a voltage and current. PD starts at 5 V and steps up through 9 V, 15 V, and 20 V, with 240 W devices adding 28 V, 36 V, and 48 V. Since watts equal volts times amps, raising the voltage is what lets a slim cable carry 100 W without overheating.

  • PD 2.0 tops out at 100 W, at 20 V and 5 A
  • PD 3.0 keeps the 100 W limit and adds better cable safety checks
  • PD 3.1 raises the ceiling to 240 W, at 48 V and 5 A
  • Phones typically pull 18 to 45 W, laptops 45 to 100 W

How to buy the right charger and cable

A PD link is only as fast as its weakest part. Cables carrying up to 60 W work on nearly any USB-C cord, but 100 W or 240 W needs a cable rated for it, because the cable carries an e-marker chip that reports its limit to the charger. To confirm a charger supports PD, look for 9 V or 15 V in its output list, or the words USB PD or Power Delivery. For phones, pick at least 9 V at 3 A (27 W); for laptops, 20 V at 3 A (60 W) or higher.

The honest take

For most people, one 65 W GaN PD charger and one 100 W rated USB-C cable replace every charger in the bag. That pair tops up a phone in under an hour and runs a thin laptop from a wall outlet. A 240 W charger only pays off for gaming laptops, and it costs a clear premium.