Most people choosing a USB-C charger should start with the device, not the charger box. Find out how much power your phone, tablet or laptop asks for. Its original charger and its spec sheet are the usual places to look. Then buy a USB Power Delivery (PD) charger that covers that number in the right power range. If your device needs 100W or less, an ordinary PD charger does the job. If it needs more than 100W, you need a charger that supports the newer Extended Power Range, and a bigger number on the box will not stand in for that support.
USB PD has two power ranges, split at 100W
According to Granite River Labs, the USB Implementers Forum (USB-IF) introduced Power Delivery 3.1 (Revision 3.1, Version 1.0) in May 2021. Its main addition is EPR (Extended Power Range), which raises the maximum from 100W to 240W (48V at 5A).
The older PD 3.0 power rules did not go away. Granite River Labs says they are kept in PD 3.1 as SPR (Standard Power Range), which is still capped at 100W.
So every PD charger falls into one of two groups:
| Range | Maximum power | Extra fixed voltages | Adjustable supply |
|---|---|---|---|
| SPR (Standard Power Range) | 100W | None beyond the PD 3.0 rules | PPS |
| EPR (Extended Power Range) | 240W (48V at 5A) | 28V, 36V and 48V | AVS |
This is the real dividing line when you shop. A charger limited to SPR cannot go past 100W, however it is marketed.
What a 140W or 144W label actually requires
Above 100W, the wattage on the box ties to specific voltages. Granite River Labs lists the EPR fixed voltages as 28V, 36V and 48V, and spells out what the in-between tiers need:
- A 140W charger must offer 28V at 5A.
- A 144W charger must also offer 36V at 4A.
Why this matters to you: a device that charges over EPR expects one of these higher voltages. If your laptop's maker says it charges at 140W, the charger you buy has to provide the 28V level, not just claim a large total.
PPS and AVS: the adjustable part
Besides fixed voltages, PD has an adjustable mode for each range.
- PPS is the adjustable supply in the standard range. Granite River Labs notes that it adjusts in 20mV steps.
- AVS (Adjustable Voltage Supply) is the EPR addition. The same source describes it as like PPS, but with no current-limit operation, and it adjusts in 100mV steps.
This guide cannot tell you which phones need PPS. The research behind it did not reach Apple, Google or Samsung documentation, so check your device maker's own charger page.
What to ignore on the box
The single biggest number. It tells you the most the charger can produce under some condition. It does not tell you which range or voltages it supports, and those decide whether your device charges at full speed.
How the choice changes by device
Phones, tablets and laptops that need 100W or less
You are inside the Standard Range. Any PD charger that meets your device's wattage is enough, and EPR support adds nothing for this device.
Laptops and workstations that need more than 100W
You need an EPR charger, because SPR stops at 100W. Match its tier to your device using the voltage requirements in the 140W and 144W section above.
One charger for several devices
This guide does not have sources on how multi-port or GaN chargers split power between ports, so read the maker's own listing before you buy.
