For those of you who own an iPhone 4 and feel the need for some extra battery life, the Exolife Rechargeable Battery Case for the iPhone 4 apparently virtually doubles the life of the iPhone along with “eliminating interference with your iPhone’s antenna.”

The Exolife Rechargeable Battery Case for the iPhone 4 comes to our attention courtesy of Rosa Golijan over on Gizmodo, who says they aren’t sure if the case actually doubles the iPhone 4 life but it is a “slim and light” case that will give your power a boost.

The Exolife Rechargeable Battery Case for the iPhone 4 weighs in a 59 grams which included the rechargeable Lithium polymer battery and features an illuminated power meter along with a polycarbonate frame and will work with the new iPhone 4, iPhone 3GS and iPhone 3G.

The Exolife Rechargeable Battery Case can be pre-ordered as of right now from Exogear and will command a price tag of roughly $90 and should see release on or about the 30th of July.