LAS VEGAS - While Apple has yet to bring native wireless charging to its lineup of iOS mobile devices, vendors at International CES were out in force this week claiming to have the first chargers for the iPhone 5, iPhone 4 and 4S models.

The vendors, WiTricity and ConvenientPower, announced iPhone sleeves that enable the smartphones to receive voltage by being placed on charging pads.

An example of Texas Instrument's wireless charging coil and chip technology. The device can be much smaller and would be the electrical receiver in a mobile device.

ConvenientPower created a sleeve based on the Qi standard (pronounced "chee") for both the iPhone 5 and iPhone 4 models. WiTricity created a sleeve for the iPhone 5 only.

The Wireless Power Consortium (WPC) also announced a next generation of its Qi charging standard that allows multiple devices to be charged on a pad as well as charged through solid objects, such as a tabletop.

Previously, the Qi wireless charging standard used "tightly" coupled inductive charging, which required enabled mobile devices to be placed in a specific space on a charging pad. The device could not be moved once charging began.

For consumers, the new Qi "resonant extension" will allow more loosely coupled charging with higher efficiency and at a lower radio frequency interference, which means it will be possible to charge without worrying about the exact position of their devices so they can charge anywhere.

The WPC demonstrated examples of the new magnetic resonance extension technology with products from ConvenientPower and PowerbyProxi along with the newest Qi-compatible wireless charging products and prototypes from Devant, Haier, Leggett & Platt, Nokia, Samsung, Texas Instruments and others.

Texas Instruments is supplying the chip technology that regulates the Qi wireless power and makes the electronic "handshake" between pad and mobile device.

There are now more than 400 Qi-enabled devices, including mobile phones, such as the Samsung Galaxy S4 and S3, Nokia Lumia 1020, LG G2, Motorola Droid Maxx and Mini and the Google Nexus 5 phone and Nexus 7 tablet.

John Perzow, vice president of market development for the WPC, demonstrated how the new pads could charge multiple mobile devices. He then held the charging pad under a table and placed an enabled smartphone on the table top. The phone began to charge.

WPC's magnetic resonant charging allows power to travel about 18mm, or about three-quarters of an inch. However, the efficiency of the charge is reduced to about 65%, Perzow said.

The extension to the Qi standard is backward compatible to the 1.1 specification, meaning about 40 million Qi-enabled mobile devices that are already in the hands of consumers can use the new charging pads, Perzow said.