Benzitech (http://www.benzitech.com/) has announced its new line of waterproof cases for smartphones and tablet computers, as well as new battery charging cases for the iPhone and iPad.

The iDry waterproof cases create an airtight seal to protect all makes and models of smartphones and tablets from everything from rainfall to being submerged 30 feet underwater. The cases float on water and feature secured waterproof ear buds, armbands and neck straps for use during more strenuous activities. Users can operate their devices’ touchscreens, listen to music and even make or receive phone calls without opening the cases.

Benzitech has also introduced two iPhone battery charging cases. The Slider iPhone battery charging case features a 2200 mAh battery that can purportedly double the battery life of the iPhone 4 and iPhone 4S. The slim design maintains the iPhone’s profile and can be attached or removed. The Slider comes equipped with a LED power state indicator.

The iWrap is a genuine leather case that features a flip cover to protect the screen of an iPhone 4 and iPhone 4S. It boasts a 1450 mAh battery and Smart LED power state indicator system.

The 6000 Z Charger case for the iPad 2 can nearly double the device’s battery life, translating to an additional seven hours of video playback or 50 additional hours of audio playback, according to the folks at Benzitech. The design also features a stainless steel stand so the user can view the iPad up in landscape and portrait modes.

The iDry waterproof cases are available now in black or yellow color schemes, and the Slider is available now in black, white, red and yellow. The iWrap and 6000 Z Charger case are scheduled to be available in March.