The "WP-PD10.BK" power transmission pad, which can charge two units of the iPhone 4 at the same time, and the WP-SL10A.BK sleeve charging case
The "WP-PD10.BK" power transmission pad, which can charge two units of the iPhone 4 at the same time, and the WP-SL10A.BK sleeve charging case
[Click to enlarge image]
The weight of the "WP-SL10A.BK" is about 40g (The iPhone 4 weighs about 137g).
The weight of the "WP-SL10A.BK" is about 40g (The iPhone 4 weighs about 137g).
[Click to enlarge image]

Hitachi Maxell Ltd announced Feb 7, 2011, that it will release a battery charger compatible with a standard created by the Wireless Power Consortium (WPC), an industry group related to wireless charging.

The company will start releasing the "WP-PD10.BK" and "WP-PD10S.BK" power transmission pads as well as the "WP-SL10A.BK," a sleeve charging case that can wirelessly receive power for Apple Inc's iPhone 4, April 25, 2011, in Japan.

The power transmission pads are printed with the "Qi mark," which indicates the compatibility with the WPC's standard. And the "coil array method," which was developed by ConvenientPower HK Ltd, was employed for them. By arraying multiple power transmission coils, Hitachi Maxell widened the area on which devices can be charged.

ConvenientPower has an agency contract with MCM Japan Ltd, which provided the new products to Hitachi Maxell as an ODM, in Japan.

The WP-PD10.BK can charge two units of the iPhone 4 at the same time. It has two power transmission units, each of which can transmit power of 5W. The WP-PD10S.BK comes with one power transmission unit and can charge one device. The WP-SL10A.BK can receive power of 2.5W.

The WP-PD10.BK and the WP-PD10S.BK measure 215 x 185 x 15mm and 112 x 188 x 15mm, respectively, and weigh about 350g and 180g. The dimensions of the WP-SL10A.BK are 63 x 125 x 40mm, and its weight is about 40g.

There are no manufacturer's suggested retail prices, but the retail prices of the WP-PD10.BK and the WP-SL10A.BK (sleeve charging case) are about ¥6,900 (approx US$83.7) and 2,900, respectively. Only the WP-PD10S.BK is scheduled to be released in May 2011.