What does 240W USB Power Delivery actually mean?
USB PD 3.1 raised the ceiling from 100W to 240W. Here's how it works, what you need for it, and whether you need it at all.
For years, USB-C charging topped out at 100W. The USB Power Delivery 3.1 specification, released in 2021, raised the limit to 240W. Here's what changed.
SPR and EPR
USB PD now has two ranges:
- Standard Power Range (SPR): fixed voltages of 5V, 9V, 15V and 20V, up to 100W (20V × 5A).
- Extended Power Range (EPR): adds 28V, 36V and 48V, giving up to 140W, 180W and 240W at 5A.
Raising the voltage instead of the current is what makes this possible. More current would need thicker, heavier cables. EPR also adds Adjustable Voltage Supply (AVS), which lets the charger fine-tune the voltage, usually between 15V and 48V.
You need all three parts
240W charging only happens when the charger, the cable and the device all support EPR:
- The charger must be rated for EPR, for example 140W or 240W.
- The cable must be a 5A cable with an EPR-capable e-marker, rated for 50V.
- The device must ask for EPR power. Only a few high-power laptops do this today.
If any one of them is missing, the system safely falls back to a lower power level, usually 100W or less.
Do you need a 240W cable?
If you own, or plan to buy, a laptop that charges above 100W over USB-C, yes. Otherwise, a 240W cable is mainly future-proofing. It works exactly like a good 100W cable today and will be ready for your next high-power device.
