Wireless charging specs are a common source of buyer disputes for a specific reason: the wattage printed on a charger’s packaging isn’t a guaranteed output — it’s a maximum ceiling that only applies under specific conditions the packaging usually doesn’t explain. And a printed Qi logo isn’t proof of certification either, which matters more than it might seem.
The Certification Tiers Behind the Number
Qi certification, managed by the Wireless Power Consortium (WPC), has distinct power tiers. Baseline Power Profile (BPP) tops out at 5W. Extended Power Profile (EPP) can reach up to 15W. Qi2’s Magnetic Power Profile (MPP) standardizes 15W with magnetic alignment, and as of Qi2 25W — launched July 2025 — that ceiling extends to 25W when both charger and phone support it.
The gap between “supports up to 15W” and “actually delivers 15W to your phone” comes down to the handshake between charger and device. A generic EPP charger paired with a phone using a proprietary fast-charging layer on top of Qi (Samsung’s Fast Wireless Charging 2.0, for example) often settles for 7.5–10W instead of the full 15W printed on the box, because full speed requires a matching protocol, not just a matching power tier.
A Documented Safety Failure, Not a Hypothetical One
WPC has published its own lab findings from testing an uncertified wireless receiver purchased from a major online retailer. The independent lab found the product failed Qi’s Test 5.4.3.1 (“object heating prevention”) — the test that verifies a charger can detect a foreign metal object sitting near the receiver and cut power before it overheats. The uncertified unit misreported the power it was actually receiving, which meant the object-detection mechanism didn’t trigger correctly; in testing, one metal test object reached 96.1°C (205°F) within 51 seconds. This is the specific failure mode a genuine Qi certification is designed to prevent — a printed “15W fast charging” claim says nothing about whether this safeguard actually works.
WPC has also taken enforcement action against sellers rather than only against products: Chinese trade press covering the wireless charging industry reported WPC formally notifying Amazon to remove uncertified listings, with Amazon Japan pulling several bestselling wireless chargers — a case industry sources linked to customer complaints about the products overheating during use.
Why the Logo Alone Doesn’t Prove Certification
A counterfeit or uncertified product can print a Qi logo that looks correct — the logo itself doesn’t verify anything on sight. WPC’s own guidance is explicit about the correct verification method: check the product against the Qi Certified Product Database, and confirm the brand name, product name, and model number all match exactly. A near-match, or a generic “Qi compatible” claim without a specific registered model number, is not the same as genuine certification. WPC has also indicated it is building a dedicated enforcement team to pursue unauthorized commercial use of the Qi trademark as a legal matter, not just a decertification issue.
A Second Bottleneck: The Power Adapter
Even a correctly matched, genuinely certified wireless charger can’t deliver its rated wattage if the wall adapter powering it is undersized. Due to conversion losses in wireless charging, a charger needs meaningfully more input power than its wireless output — roughly an 18W adapter minimum to actually deliver 15W wirelessly.
What to Ask a Supplier
- Which specific power profile is certified — BPP, EPP, or MPP/Qi2 — and what is the exact brand name, product name, and model number registered in the WPC Qi Certified Product Database? Ask for the database listing directly rather than accepting “Qi certified” as a verbal claim.
- Is the stated wattage the charger’s maximum ceiling under ideal handshake conditions, or a guaranteed output across common phone brands?
- What wattage does the bundled or recommended power adapter supply, and is it sufficient to reach the charger’s rated wireless output?