As the wireless charging industry gets more competitive, Qualcomm is trying to make the Rezence standard it helped build stand out. The chipmaker has slightly altered how the standard works within its WiPower charging pads so that it can charge devices with metal cases.

The Rezence standard uses magnetic resonance between inductive couplers to support wireless charging over short distances. But the new version operates over the 6.78 MHz frequency band, which is more tolerant of metal objects in the charging field. The frequency has been used before to allow metal objects such as keys and coins, to remain near the charging pad without causing interference. The new WiPower charging pads extend that ability to metal devices, and without sacrificing its 22-watt power output.

Developed by the Alliance for Wireless Power, the Rezence standard can transmits up to 50 W of energy to compatible devices. It sends wireless power to multiple devices without the need for precise alignment or direct physical contact, though the device cannot be further than 5 centimeters from the charging pad. The specification is able to charge cell phones, smartphones, tablets, notebooks, laptops, and PC peripherals.

Wireless charging through metal backs has been one of the main obstacles to widespread use of the technology, according to Steve Pazol, Qualcomm’s general manager of wireless charging. “Building a wireless charging solution into devices with metal exteriors is a significant step forward for moving the entire industry,” he said in a statement.

Qualcomm was one of the founding members of the A4WP, which earlier this year merged with Power Matters Alliance, another industry group for wireless charging. The organization is competing against the Qi standard being developed by the Wireless Power Consortium, which was recently upgraded to support fast charging for mobile phones.