USB Fast-Charging Sockets — Choosing Between QC, AFC and USB-C PD for Your Market
QC, PD, PPS and AFC are negotiation protocols between the port and the device. The mainstream spec: one USB-C PD port plus one or two USB-A QC ports. What predicts your returns rate is not the per-port wattage — it is the total power budget when every port runs at once. This guide covers the protocols, the power budget, and how to spec by market.
1. The Protocols at a Glance
| Protocol | Typical Max | Where |
|---|---|---|
| BC 1.2 | 5V/1.5A | Cheap multi-ports; slow for phones |
| QC 3.0 | 18W | USB-A ports; most common in UK extension leads |
| USB-C PD | 20W–100W | USB-C ports; Apple/Samsung ecosystems |
| PD 3.0 + PPS | 45W-class, cooler | Newer USB-C ports; premium lines |
| AFC / FCP | ~15–25W | Samsung/Huawei handsets |
The protocols are layers, not competitors: PD covers the USB-C world, QC covers the huge USB-A installed base — both coexist in one well-designed strip.
2. Why Ports Slow Down Together
A "2×20W PD + 2×QC" four-way strip usually shares one internal converter. When every port runs, per-port output drops. That is normal engineering — but it must be documented.
Ask the factory for the simultaneous-load test report: it states what each port delivers when all ports work together. Your returns rate will be built on that number, not on the port labels.
3. How to Spec by Market
- UK / Europe retail: USB-C PD 20W is the baseline; add one or two USB-A QC ports for legacy devices.
- Travel adapters: one PD + one QC covers 90% of travellers; more ports add cost and heat.
- Africa / South Asia price-sensitive channels: BC 1.2 + QC keeps cost down.
- Office / contract furniture: prioritise simultaneous output and thermal design over port count.
4. Certification Notes
Besides the socket standard, the USB module needs its own safety report (EN 62368-1 influence) and EMC results — with the module named in the documents. Anonymous charging modules are the number-one cause of returns in this category.
Compare charging configurations across our extension socket lines, or request a formal quotation — full electrical specs within 24 h.
Frequently Asked Questions
Can a USB-C PD port charge any phone?
Yes, at basic speed — PD ports fall back to 5 V for non-PD devices. Protocol match decides speed, not whether charging happens.
Is QC 3.0 obsolete?
No. QC 3.0 (18 W) remains the workhorse for USB-A ports in UK extension leads and still fast-charges the huge installed base of QC-compatible Android devices.
What does PPS add on top of PD 3.0?
PPS lets the charger adjust voltage in fine steps so phones manage heat better — meaningful for 45 W-class charging and premium lines.
Why does my power strip slow down with several ports in use?
Ports usually share one internal converter. Total demand above the shared budget lowers per-port output. Normal engineering — but it should be documented, so ask for the simultaneous-load test report.
Do USB charging ports in a socket need their own certification?
Yes. The USB module needs its own safety report (EN 62368-1 influence) and EMC results, with the module named in the documents.
Should retail packaging advertise 20 W or 45 W?
Advertise what the simultaneous-load report defends. Numbers that hold only on one port generate returns; specs that survive all ports at once generate reviews.