USB C, Lightning and Qi: charging standards explained for sellers

USB C describes the shape of the plug. It says nothing about how much power flows or whether any data moves, and two cables with identical ends can differ wildly inside.

One may carry slow charging and no data. Another may support USB Power Delivery at high wattage, video output and fast file transfer, yet both wear the same plug. Buyers return the weaker one.

Split the description into fields. The connector at each end, data support, Power Delivery support and the maximum power printed on the label each get a slot of their own. Customers filter by these fields, so an empty slot hides the product from that search and sends the shopper to a rival with a complete listing.

Lightning is Apple’s own connector, found on older iPhones, some iPads, AirPods cases and a long tail of accessories that were designed around it years ago. Cables for it are certified under Apple’s MFi programme, and an uncertified copy can trigger an unsupported accessory warning on the phone screen.

Newer iPhones have moved to USB C, so a shopper with last year’s phone and one with this year’s need different cables. List compatibility by device model, not by brand. A line reading compatible with iPhone misleads.

Keep Lightning lines while your sales report shows demand, and mark them clearly so nobody buys one for a new phone.

USB Power Delivery is a negotiation. The charger and the device agree a voltage and current, within whatever limit the cable can carry without overheating or damaging the port. Cables built for higher power hold a chip, called an e-marker, that reports the limit.

The wattage you print must come from the charger’s own label or datasheet, not from a supplier’s sales sheet or the box of a similar model. Check a sample unit too. Fast charge means nothing without a named protocol. Power Delivery is the open one, and some brands run proprietary variants that suit only their own phones, so name which one you mean.

A multi-port charger splits its output. The headline wattage covers the whole unit, and a single port gets less once a second device is plugged in, so state the power for each port.

Qi is the wireless charging standard run by the Wireless Power Consortium, and most phones, earbud cases and some watches support it. A Qi pad is the broad-compatibility product.

Qi2 adds a ring of magnets that aligns the phone with the charging coil, in the same spirit as Apple’s MagSafe, and it needs a magnet-ready case. Thick cases and metal plates weaken the hold. So say which cases work.

Smartwatches and many fitness bands charge on their own proprietary pucks that are not Qi at all, so catalogue those under the device rather than under wireless chargers.

Fill the attribute sheet from the physical product. Plug each cable and charger into a phone through a USB power meter, test every pad with the phone in its case, and note what really happens.

Write titles straight from the fields, with connector first, then power, then wireless profile, then length, because customers search by connector and by device. Filters should offer both.

Add a return code for wrong cable type. It shows which listings confuse buyers. This week, take your ten best-selling cables, plug each one into a meter and phone, and re-check what its listing says against what you measure.