Your phone probably snaps onto its wireless charger with a satisfying click. That click is a ring of small magnets — and it is doing more than feeling nice. It is making the charger work properly.
Why alignment matters
Wireless charging works by induction: a coil in the charger creates a magnetic field, and a coil in the phone turns it back into electricity. The two coils must line up closely. If they are off-center, efficiency drops and the phone charges slowly — or not at all. A ring of magnets around each coil pulls the phone into perfect position automatically.
More than phones
Earbud cases use the same trick — magnets hold the buds in place and align the charging contacts. Magnetic connectors and pogo-pin chargers use magnets to mate plugs in the right orientation, so you cannot plug them in wrong. Smartwatches, tablets and power tools all snap onto chargers the same way.
Fancy field shaping
Some charging pads use special magnet arrays — like a Halbach array — that concentrate the field on one side and cancel it on the other. That keeps the useful field pointing at the device and reduces stray field elsewhere. You can read more in our Halbach array guide.
Practical tip
If you are designing a magnetic charger, small NdFeB ring magnets are the standard choice. Test the alignment force with the actual device — too weak and the phone slips, too strong and it is hard to pull apart.
Read on: Halbach arrays explained → · magnets in 3C electronics →