The distance for effective wireless charging, specifically using the Qi standard, is up to 4 cm (1.6 inches).
Understanding Wireless Charging Distance
Wireless charging, particularly inductive charging based on the Qi standard, requires close proximity between the charging pad and the device being charged. The power transfer efficiency drops significantly as the distance increases.
Key Facts About Wireless Charging Distance:
- Qi Standard: The Qi standard is the most popular for inductive wireless charging.
- Maximum Distance: It supports power transfer up to 4 cm (1.6 inches).
- Optimal Placement: Devices need to be very close or directly on the charging pad for efficient charging.
Why the Limited Distance?
The limited distance is due to the nature of inductive power transfer. The charging pad creates an electromagnetic field, which induces a current in the receiving coil within the device. This process is most efficient when the coils are closely aligned and within a short distance. Greater distances weaken the electromagnetic field, reducing the induced current and slowing down or preventing charging.
Implications of the Distance Limitation
- Precise Alignment: Users must carefully align their devices with the charging pad.
- Limited Obstructions: Thick cases or other obstructions can increase the distance and interfere with charging.
