If you've shopped for power banks, chargers, or electronics recently, you've encountered USB-C Power Delivery, often abbreviated as USB-C PD or just PD. This technology has revolutionised how we charge our devices, enabling everything from rapid smartphone charging to powering laptops from compact power banks.
But what exactly is USB-C Power Delivery? How does it work? And most importantly, what do you need to know to make smart purchasing decisions? This guide explains the technology in practical terms.
Understanding the Basics
USB-C Power Delivery is a fast charging standard that allows devices to negotiate and deliver much higher power levels than traditional USB. While standard USB provides a fixed 5 volts at limited current (typically 0.5-2.4 amps), USB-C PD can dynamically adjust voltage and current to deliver up to 240 watts of power in the latest specification.
The key innovation is intelligent negotiation. When you connect a USB-C PD device to a compatible charger or power bank, they communicate to determine the optimal power delivery. The device tells the power source what it needs, and the power source provides exactly that, no more and no less.
Why Variable Voltage Matters
Traditional USB always delivers 5 volts. This works fine for low-power devices like phones, but causes problems for higher-power devices like laptops that need more voltage to charge efficiently.
USB-C PD supports multiple voltage levels: 5V, 9V, 15V, and 20V are standard, with the latest specifications adding 28V, 36V, and 48V for high-power applications. By increasing voltage while managing current, USB-C PD can deliver substantial power through cables thin enough to remain practical.
Power (Watts) = Voltage (V) × Current (A). To deliver 100W at 5V would require 20A, needing thick cables and generating heat. At 20V, the same 100W requires only 5A, enabling thinner cables and cooler operation.
USB-C PD Power Levels
The USB-C PD specification defines standard power levels that chargers and devices typically support. Understanding these helps you choose compatible equipment.
Common Power Tiers
18-20W: The entry point for USB-C PD, suitable for fast charging smartphones. Most iPhones and Android phones can accept 18-20W from a USB-C PD source, charging significantly faster than with standard USB.
25-30W: Common for mid-range chargers and power banks. Provides rapid smartphone charging and can slowly charge some tablets. Samsung's Super Fast Charging uses 25W.
45W: A popular tier for tablets and lightweight laptops. iPads charge at up to 30-45W. Many ultrabooks and thin laptops charge adequately at 45W, though possibly slower than their included chargers.
60-65W: The sweet spot for most USB-C laptops. MacBook Air, Dell XPS 13, and similar ultrabooks typically include 60-65W chargers. A 65W power bank can fully replace your laptop charger.
87-100W: Required for larger laptops like MacBook Pro 15/16 inch models and gaming laptops with USB-C charging. Fewer power banks support this level, and those that do are typically larger and more expensive.
140-240W: The newest USB-C PD 3.1 specification enables up to 240W, targeting gaming laptops and mobile workstations. Still relatively rare in portable power banks.
- Smartphones: 18-30W (fast charging)
- Tablets: 20-45W
- Ultrabooks: 45-65W
- Pro Laptops: 87-100W
- Gaming/Workstation: 140W+
USB-C PD vs Other Fast Charging Standards
USB-C PD isn't the only fast charging technology, but it's becoming the universal standard. Here's how it compares to alternatives.
Quick Charge (Qualcomm)
Qualcomm's Quick Charge technology predates USB-C PD and is common in Android devices with Qualcomm processors. Quick Charge 3.0 delivers up to 18W, while Quick Charge 4+ reaches 27W and is actually compatible with USB-C PD.
Most modern chargers and power banks support both Quick Charge and USB-C PD, so compatibility isn't usually an issue. The technologies can coexist on the same port.
Proprietary Standards
Some manufacturers use proprietary fast charging that only works with their specific devices and chargers. Examples include Oppo's SuperVOOC (up to 80W), OnePlus Warp Charge, and Huawei SuperCharge.
These often deliver faster charging than USB-C PD for their specific devices but won't fast-charge other brands. They're less common in power banks, and if supported, the power bank usually also supports USB-C PD for universal compatibility.
Apple's Approach
iPhones support USB-C PD for fast charging (up to 27W on iPhone 15 Pro models), requiring a USB-C to Lightning cable or the newer USB-C port on iPhone 15. MacBooks have used USB-C PD for years. Apple fully embraces the USB-C PD standard despite their historical preference for proprietary connectors.
Choosing USB-C PD Power Banks
When selecting a power bank with USB-C PD support, consider these factors:
Output Wattage
Match the power bank's USB-C PD output wattage to your devices. For smartphones only, 18-20W is sufficient. For laptops, you'll need 45W, 60W, or higher depending on your model. The power bank must meet or exceed your device's requirements for optimal charging speed.
Input Wattage
USB-C PD works both ways. A power bank with high-wattage input recharges itself faster. A 10,000mAh power bank with 18W input takes about 3.5 hours to charge, while one with only 10W input might take 6 hours. Look for power banks that support at least 18W input, preferably more for larger capacities.
Cable Quality
Not all USB-C cables support USB-C PD, especially at higher wattages. Cheap cables may be limited to 15W or even 5V/0.5A. For reliable fast charging, use cables rated for at least 60W (3A at 20V). For laptop charging, look for 100W-rated cables marked with e-marker chips.
If fast charging isn't working, try a different cable before assuming your power bank or device is faulty. Cable quality issues cause most USB-C PD problems.
Safety and Compatibility
One of USB-C PD's strengths is its safety. The negotiation protocol prevents devices from receiving inappropriate power levels. If your phone only supports 18W, a 100W charger won't force 100W into it; the devices negotiate and settle on 18W.
This intelligent negotiation means you can safely use high-wattage chargers with low-wattage devices. A 100W power bank works perfectly with your smartphone, providing only the power the phone requests.
Backwards Compatibility
USB-C PD ports remain backwards compatible with older USB standards. If you connect a non-PD device, the port falls back to standard USB power delivery (typically 5V/2.4A). You won't get fast charging, but charging will still work.
Similarly, USB-C PD devices can charge from non-PD power sources, just at slower standard rates. Compatibility is universal; only the speed varies.
The Future of USB-C PD
USB-C PD continues evolving. The USB-C PD 3.1 specification introduced Extended Power Range (EPR), enabling up to 240W delivery with additional voltage options (28V, 36V, 48V). This opens the door for USB-C to power even desktop computers and gaming laptops.
Regulatory changes are also driving USB-C PD adoption. The European Union now requires USB-C charging for most consumer electronics, and other regions are following suit. USB-C PD is becoming the true universal charging standard that the original USB aspired to be.
When purchasing power banks and chargers today, prioritising USB-C PD support ensures compatibility with current and future devices. It's the safest bet for long-term utility.
For power bank recommendations with excellent USB-C PD support, check our comparison tool to find options matching your specific power requirements.