USB Power Delivery, usually shortened to USB PD, is the protocol that lets a charger and a device negotiate how much power flows between them, rather than simply pushing a fixed voltage down the line. The wattage figure on a charger box is a ceiling, not a guarantee — what a device actually draws depends on what it asks for during that negotiation, capped by the weakest link in the charger, cable, and device chain.
What changed in 2026
- Extended Power Range (EPR) pushed the ceiling to 240 W, up from the old 100 W Standard Power Range cap, enabling single-charger setups for high-draw workstation laptops.
- More laptops shipped without a bundled charger, relying on USB PD chargers users already own, which put more pressure on buyers to understand actual wattage needs.
- GaN (gallium nitride) chargers became the default for multi-port high-wattage chargers, packing 100 W-plus output into a much smaller footprint than older silicon designs.
How the negotiation actually works
When you plug a USB-C cable between a charger and a device, the two exchange a short digital handshake before any meaningful power flows. The device reports what voltage and current combinations it can accept; the charger reports what it can supply; they agree on the highest mutually supported wattage. This is why a 100 W charger does not overpower a phone that only requests 25 W — the phone simply never asks for more than it can handle.
Wattage tiers and what they cover
| Wattage range |
Typical devices |
Notes |
| Under 20 W |
Basic phone charging (older standard) |
Largely replaced by faster PD charging |
| 20-30 W |
Phones, earbuds cases, small tablets |
Standard fast-charge tier for most phones |
| 45-65 W |
Ultrabooks, larger tablets |
Common single-port laptop charger tier |
| 100 W (Standard Power Range) |
Mainstream laptops, docks |
Covers most non-workstation laptops |
| Up to 240 W (Extended Power Range) |
Workstation and gaming laptops |
Requires an e-marked cable to deliver full wattage |
Why the cable is part of the equation
Wattage above 60 W requires a cable with an embedded e-marker chip; without one, the connection caps at 60 W regardless of what the charger and device could otherwise negotiate. This trips people up constantly — see our USB-C cable guide for how to tell which cables actually support high wattage.
Matching a charger to your actual needs
Buying the highest-wattage charger available is not necessary for most people, but buying too low a wattage for a workstation laptop will noticeably slow charging, especially under heavy load where the laptop draws more power than it can pull in. Check your device's rated charging wattage — usually in its specs or on the original charger — and buy a PD charger that meets or modestly exceeds it, with a certified cable to match.
Common mistakes
Assuming higher wattage charges faster on every device. Charging speed is capped by what the device requests, not by charger capacity beyond that point.
Using a bargain cable with a high-wattage charger. Without an e-marker chip, the cable itself caps the connection at 60 W no matter what the charger supports.
Ignoring multi-port chargers' shared wattage pools. Many multi-port GaN chargers split total wattage across active ports, so plugging in a second device can slow charging on the first.
FAQ
Can a high-wattage charger damage a low-power device?
No. USB PD negotiation prevents a device from receiving more power than it requests, so pairing a 100 W charger with a 20 W device is safe.
What is the difference between Standard Power Range and Extended Power Range?
Standard Power Range tops out at 100 W. Extended Power Range, a newer addition to the USB PD spec, extends that ceiling up to 240 W for devices and chargers that both support it.
Do all USB-C ports support Power Delivery?
No. Some USB-C ports are data-only or support only basic charging without full PD negotiation. Check the port or device specs to confirm PD support.
Where to go next