Eton's slim solar charger for iPhone 4 (Green Gadget of the Week)

The Mobius combination case and solar charger includes a standby switch that prevents power from being fed into the phone during the charging process.

(This is the latest in a regular weekly series of spotlights on green technology that’s accessible to you and me. If you have a green technology or gadget to suggest for coverage, please send a note via my contact email.)

As big a fan I am of solar charging technologies, I have had one big gripe about the design of many solar chargers for mobile phones. But I really like the looks of the new Mobius rechargeable solar battery and case for Apple iPhone 4.

The product from Palo Alto, Calif.-based Eton has the solar charger on the back of the case, like many competing products. But the case itself is more like the slim-line ones that you can snap onto the phone. Plus, it protects the top of the phone if it is dropped, which isn't the case with many other products.

The case is 2.44 inches wide by 5.1 inches high by 0/875 inches deep and it weighs about 3.4 ounces.

Approximately one hour of charging time in the sun with Mobius' monocrystal solar panel will add an additional 25 minutes of talk time to an iPhone 4. (Or 20 minutes of Internet time if that's your preference.) When fully charged, the 1800 mAh battery provides up to five hours of talk time via a 3G wireless network. (The company makes that distinction, which makes me wonder if 4G phones will eat up battery life even quicker than 3G ones. Hmmm.)

Another great design feature: the gadget includes a solar charge and battery indicator. AND, you can switch it off using a standby feature to prevent power from dumping into your phone during charging. Oh, and you CAN charge via a Micro-USB cable if you prefer.

Mobius can be bought from Amazon.com for a list price of $80.

Past Green Gadgets of the Week: