Thanks to a listing from Amazon.de, the first details are now available for the Venom Dual Charging Stand and Battery Pack for DualShock 4. You can check out a pair of photos from the officially licensed product below this paragraph.
The stand itself can hold and recharge two controllers at the same time. LED lights are included so that you can tell when the gamepads have been fully charged. The product uses a power adaptor, which is included in the package.
The Venom Dual Charging Stand and Battery Pack is hitting Germany sometime later this year. It is unknown if we are going to see the same product in North America at some point. If you are looking for an already-released domestic product designed to extend the battery life of the DualShock 4, you may want to check out the Nyko Power Pack with this link from Amazon.com.