Sourcing wireless chargers
One claim in this category can be checked against a third party in a minute — and it is the one most often made loosely.
Published · 7 min read · By YCP Team
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Certified, compatible, and how to tell
The mark is licensed. Certification is run by the standards consortium that owns it, and the certified products are published in a public database searchable by company and model. That makes this the rare sourcing claim that a buyer can verify against an independent third party before paying anything.
Check the model, not the company. A factory may hold certification for one model and be selling you another. Ask for the specific certified model designation and look it up; then confirm the product you are buying is that model rather than a variant that shares a name.
Ask who holds the certification. If the factory is building on a solution house's reference design, the certification may belong to the design owner or to a different assembler, and whether you may rely on it — and whether you may print the mark on your own branded version — is a separate commercial question with a separate answer.
Printing the mark without a licence is a trademark matter as well as an unsupported claim. If you are branding the product, establish before production whether your version needs its own certification and who pays for it.
And separate the profiles. Later revisions of the standard add magnetic alignment and higher power tiers, and a product may be certified against one profile and marketed against the name of another. Specify the profile and the revision in writing, then confirm the listing matches.
The thermal problem is the product
Where the losses go. Every watt that does not cross the coil gap becomes heat, and the pad is pressed against the phone at the point where its battery sits. Heat is the main cause of battery ageing, so a wireless charger that runs hot is not only unpleasant, it is degrading the device it is charging — and that is what a customer eventually notices.
Alignment is not a detail. Coil-to-coil offset collapses efficiency and turns the remainder into heat. A single-coil pad requires the user to place the phone accurately; multi-coil designs and magnetic alignment exist precisely to remove that requirement. Decide which problem you are solving before you choose the design.
The thermal path out. Ferrite shielding, the material and thickness of the top surface, any internal heat spreader and whether the design uses a fan. A pad that feels cool because it is throttling is a slow charger; a pad that feels cool because it moves heat is a good design. Test for delivered energy over time, not for surface temperature alone.
Foreign-object detection, and treat it as safety. It is what stops the coil dumping energy into a coin, a key or a card left on the pad. Ask how it is implemented and test it deliberately with a metal object and with a card — this is a test you should run before you order, not a specification line to accept.
Magnets, where the design uses them, carry their own considerations: cards and some medical devices are affected by strong fields, and packaging in several markets is expected to warn about it. Establish the warning requirements for your market rather than copying the factory's artwork.
What the pad is worth without its adapter
A wireless charger is only as good as what is feeding it. Most pads need a specific input voltage and current profile to reach their rated output, and a pad sold without a matching adapter will run at whatever the customer happens to plug in — usually less. If the packaging claims a fast-charge figure, the adapter that achieves it has to be in the box or named on it.
Specify the input side explicitly: connector, required voltage and current profile, whether an adapter is included, and what the pad does when it is fed less than it needs. A pad that silently falls back to slow charging generates support tickets that read as a defect.
The cable matters for the same reason as everywhere else in charging. An unrated or thin cable between the adapter and the pad limits the whole chain, and if you bundle one, specify it as carefully as the pad.
And test the whole chain the way a customer will use it: the bundled adapter, the bundled cable, a phone in a case, on a warm desk, overnight. Almost every complaint in this category comes from that combination rather than from a bench measurement.
Specifying, and choosing the factory
The specification: profile and revision, certified model designation, coil count and arrangement, magnetic alignment or not, input connector and required profile, whether an adapter and cable are included, foreign-object detection behaviour, surface material and finish, non-slip treatment, thermal design, and the markings on the product.
Ask the design question. Is this your own design or a reference design, who can change the firmware, and who holds the certification? A charger is a small embedded system, and the answer decides whether a field problem can be fixed or only replaced.
Ask what is tested on the line: output under a standard load, alignment tolerance, temperature rise, foreign-object detection function, and high-voltage testing where the pad includes its own mains supply.
Then buy three. Test one with a phone in a thick case, deliberately off-centre, in a warm room, overnight, and measure how much energy actually reached the battery. Provoke foreign-object detection with a coin and a card. Take one apart and look at the coil construction, the ferrite, the thermal path and the control board. Keep the third sealed and dated.
Every supplier on this site is a manufacturer, and the registered-scope check is one of the things confirmed before a listing goes live.
Questions people actually ask
What is the difference between Qi-certified and Qi-compatible?
Certified means the product passed the standards consortium's certification programme and is listed in its public database under a specific model. Compatible is a description of intent with no third party behind it. Ask for the certified model designation, look it up before paying, and confirm the product you are buying is that model rather than a variant sharing the name.
Why do wireless chargers get hot?
Because inductive transfer is materially less efficient than a cable and every watt that does not cross the coil gap becomes heat — right against the part of the phone where the battery is. Misalignment makes it worse. Heat is the main driver of battery ageing, which is why coil design, alignment and the thermal path out of the pad are the engineering that matters.
What is foreign-object detection and does it matter?
It is the function that stops the coil dumping energy into a coin, a key or a card left on the pad, and it is a safety function rather than a feature. Ask how it is implemented and test it deliberately with a metal object and a card before you order.
Does a wireless charger need its own adapter?
Usually yes to reach its rated output. Most pads require a specific input voltage and current profile, and one sold without a matching adapter will run at whatever the customer plugs in. If the packaging claims a fast-charge figure, the adapter that achieves it must be in the box or named on it.
Can I print the Qi logo on my own branded charger?
Only under licence, and only for a certified product. If you are branding a factory's design, establish before production whether your version needs its own certification, who holds the existing certification, and who pays for the new one — printing the mark without a licence is a trademark matter as well as an unsupported claim.
How should I test a wireless charger sample?
The way a customer uses it: bundled adapter and cable, a phone in a thick case, deliberately off-centre, in a warm room, overnight — and measure the energy that actually reached the battery rather than the surface temperature. Then provoke foreign-object detection with a coin and a card, and take one unit apart to inspect the coil, the ferrite and the thermal path.