Wireless charging explained: how it works and whether it is worth it
Wireless charging lets you charge a phone by placing it on a pad, with no cable. It is convenient, but it is not faster than a good cable and it has a few trade-offs.
How it works
The pad contains a coil that makes a changing magnetic field. A matching coil inside your phone picks it up and turns it into power. Most phones use a standard called Qi, so a Qi pad works with any Qi phone.
The trade-offs
- Slower. Wireless charging is usually slower than the same phone’s fast wired charging. Some energy is lost between the two coils.
- Warmer. The lost energy becomes heat. Heat is the thing that wears batteries most, so see does fast charging damage your battery?.
- Alignment. If the phone slips off the centre of the pad, charging slows or stops.
- Cases. Thick cases, metal plates and magnetic wallets can block it.
How to check if your phone supports it
Look in the spec sheet under charging for wireless or Qi. Many budget phones do not have it, and the back of the phone being glass is not proof. See how to read a phone spec sheet.
When it is worth it
- You charge at a desk or beside the bed and want a simple drop-and-go habit.
- You hate plugging in a cable several times a day.
- You want less wear on the charging port.
When to skip it
- You need the fastest top-up before leaving the house.
- The phone you want does not support it and the model costs more to get it.
Getting the best from it
Use a charger and pad that match your phone’s supported power, remove a thick case, and keep the pad in a cool spot. Estimate your own charging time with the charging time calculator, and see how long a phone takes to charge.
