Why does a wireless charger work with the case off but not with it on?

Main answer · Wecent Editorial Team

Short answer: Usually the charger is fine. The case adds distance between the phone and the pad, or contains metal, a magnet, a card or a grip that blocks or weakens the energy transfer. Try a thinner plastic case, remove anything stuck to the back and centre the phone on the pad. If it works bare, the case is the cause.

How wireless charging crosses the gap

A wireless charger sends energy from a coil in the pad to a coil in the phone through a magnetic field. The field weakens quickly with distance, and anything that interferes with it reduces or stops charging. A case sits right in that gap.

What in a case causes trouble

• Thickness. A thick case increases the distance between the coils.
• Metal. Metal plates, metal rings and metallic finishes absorb the energy and heat up.
• Magnets. Some magnetic mounts or car-mount plates shift alignment or disturb charging.
• Cards and coins. A card or coin between the phone and the pad can block the field and may heat.
• Grips and rings. A stuck-on grip lifts part of the phone off the pad and can cause misalignment.
• Battery packs. A battery case may not pass charging through at all.

Test it step by step

1. Put the bare phone on the pad and check that it charges.
2. Add the case, centred, and check again.
3. Remove cards, rings, grips and metal plates from the case.
4. Try a different, thin, plastic case.
5. Try another charger, to confirm the first is not at fault.

Fixes

• Use a thin, plastic or silicone case that is designed to work with wireless charging.
• Move the phone slightly until the charging icon appears, and then leave it still.
• Remove metal plates and accessories during charging.
• If you need the thick case, use a wired charger instead.

When the charger really is at fault

If the bare phone also fails on the pad, and works on another pad, the first charger may be faulty or too weak. Check the cable and power adapter as well.

For brands

Say in the manual that cases of a certain thickness or with metal parts can stop charging, and show a simple diagram. It prevents a lot of avoidable returns.

Where this answer says to confirm with Wecent, the detail is not published on the product page and has to come from the datasheet or the factory. General facts come from the regulators, standards bodies or device makers named in the text.