Modern charging sounds complicated: USB-C, PD, PPS, GaN, wattage numbers everywhere. But the basics are simpler than the internet makes them seem.
This article breaks down what each term actually means, how they work together, and what actually matters in real-world use.
USB-C Is Just the Connector (Not the Power)
USB-C describes the shape of the port, not how fast or how much power flows through it.
A USB-C cable can carry:
- Basic charging
- Fast charging
- Data
- Video
- Audio Or none of those particularly well.
Key idea: USB-C is the pipe, not the pressure.
Charging speed depends on what happens after the cable is plugged in.
Power Delivery (PD) Is the Negotiation
USB-C Power Delivery (PD) is a smart negotiation process between:
- The charger
- The cable
- The device
Before higher power flows, all three agree on:
- Voltage
- Current
- Maximum safe wattage
If any part of the chain does not support higher power, charging automatically slows down.
This design:
- Prevents overheating
- Protects batteries
- Avoids unsafe power draw
That is why devices do not pull full wattage unless everything supports it.
Why Cable Quality Actually Matters
Even with a high-watt charger, the cable still determines how much power reaches your device.
Low-quality cables often have:
- Thinner internal wiring
- Higher electrical resistance
Higher resistance causes:
- Voltage drop
- Energy loss as heat
- Slower charging
For charging above 60W, USB-C cables require an E-Marker chip to communicate their power capability. Without it, the charger limits output for safety.
Rule of thumb:
If a cable feels warm, energy is being wasted before it reaches your device.
GaN Is About Efficiency, Not Speed
GaN (Gallium Nitride) does not make devices charge faster on its own.
What it does is:
- Switch power more efficiently
- Generate less heat
- Allow chargers to be smaller and lighter
This efficiency is why compact GaN chargers can safely deliver high wattage without becoming bulky or hot. A modern 100W adapter is a good example of how high power no longer requires a large, inefficient power brick.
Same wattage. Better engineering.
How Everything Fits Together
A simple way to think about modern charging:
- USB-C: the connector shape
- Power Delivery (PD): the power agreement
- Cable quality: how much power can actually pass through
- GaN: how efficiently the charger handles that power
Fast charging only works when all four align.
Common Misconceptions
Many charging myths persist because advice written for older USB standards is still being repeated today.
If you want a deeper breakdown of how these myths formed and why they linger, I covered that context in a longer Myths vs Facts article on The Urban Geek blog.
- Higher wattage always charges faster - No. Devices only draw what they request.
- GaN chargers are unsafe or too powerful - GaN improves efficiency and thermal control.
- All USB-C cables are the same - Cable specifications quietly limit performance.
Most confusion around charging comes from mixing up connector standards, power protocols, and component limitations.
Final Takeaway
Most charging issues are not about raw wattage.
They come down to compatibility, negotiation, and efficiency.
Once that clicks:
- USB-C feels less confusing
- Power Delivery stops sounding risky
- GaN stops sounding like marketing hype
It is simply modern power design working as intended.
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