The Wireless Power Consortium’s (WPC) Qi wireless charging standard is poised to develop at accelerated rates in the coming years. Following the release of Qi2 in 2023, which introduced the Magnetic Power Profile (MPP) for device alignment and up to 15W of wireless charging power, even greater advancements are anticipated with the upcoming Qi v2.1 slated for release in the coming months.
Qi v2.1 builds upon the foundation set by Qi2 with features like the MCPE/MCPM magnetic covers and moving coil EPP/MPP PTx. Unlike the previous MPP which aligns the wireless charger and receiving device, this new solution takes transmitter and receiver alignment to the next stage by allowing positioning adjustments of the transmitter itself. Providing support for magnetic cases and other phone accessories, the Qi v2.1 is expected to not only impact the wireless charging market, but a rapidly growing phone accessory market as well.
Native support for EPP and BPP can be expected with Qi v2.1 through the Magnetic Cover Power Enhancement (MCPE). The technology enables MCPE-compatible magnetic phone covers to detect phones supporting EPP or BPP and transition into MPP mode accordingly. This switch enhances power transfer efficiency by activating the MPP protocol at a working frequency of 360KhZ for improved wireless charging performance.
Enhanced magnetic performance is also anticipated for phones that natively support MPP using the Magnetic Cover Power Magnet (MCPM). The MCPM enables magnetic alignment through another method known as magnetic coupling, enabling use of accessory covers during wireless charging via ‘feedthrough magnets’.
With wireless charging compatible cases and accessories expected to rise, specifications from Qi v2.1 onwards will broaden to cover accessory standardization, ensuring that all magnetic attachments fulfill safety and performance standards before they are released on the market.
Qi v2.1’s Moving Coil Transmitter (MC) technology builds upon its predecessor MPP by enabling adjustment within the transmitter to match the charging device’s receiver. This allows wireless devices to achieve an alignment accuracy of up to 2mm, even with air gaps of 2mm between transmitter and receiver coils. At present, MC supports charging for both MPP and EPP profiles at speeds of up to 15W.
Also accompanying Qi v2.1 is the Advanced Power Profile (APP). Building upon capabilities of the previous BPP and EPP, the APP can be expected to be a mainstay of the wireless charging ecosystem moving forward, driving further enhancements to power transfer and device compatibility.
A Qi2 Ready trademark is expected to be released as part of the Qi v2.1 specification and will be available to WPC members who have met the required standards. The trademark will signify device and accessory compliance with the latest Qi2 wireless charging protocols and a guarantee of quality and compatibility within the Qi2 ecosystem.
As the Qi wireless charging standard becomes more widespread, Qi 2.0 certifications have covered 68.92% of the market as of 2024, a staggering increase from the 30.47% covered by Qi 1.3.3. Since June 2023, Qi 1.3.3 certifications have plummeted, indicating a clear shift towards modern wireless charging standards.
The trend suggests that manufacturers are looking for safer, efficient charging standards to meet growing demand for higher power profiles, especially as 25W charging capabilities become the standard.
However, as power transmission capacity increases, the risk of foreign object detection (FOD) failures increases, which can result in overheating or damage to both devices and the surrounding environment. Regulation of the moving coil transmitter, magnetic cases, as well as EPP and MPP devices are therefore critical for improving power transfer efficiency without compromising safety.
Advancements will also present additional challenges in maintaining backward compatibility, and more resources will be needed on the Multi-Phase Load Analysis (MPLA) front to ensure power transmissions between new and old devices without violating safety standards.
China's recent updates to radio frequency regulations pose significant challenges for Qi2 device trade in the region. The new rules, effective from September 2023, restrict the use of frequencies above 148KhZ power transfer, directly ruling out Qi2’s MPP which operates at 360kHz.
In response, local manufacturers such as Xiaomi and Convenient Power have proposed a low-frequency (LF) variation of MPP that operates within the allowed 148kHz threshold and a power output of 30W. Moving forward, WPC and its members will continue to navigate evolving regulations by adapting Qi2 to meet both China and the greater market’s needs. The outcome of these discussions will be key to Qi2’s future presence in the global landscape.
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