Specifications
The full name of the Medis product is the 24/7 Xtreme Portable Power Solution and the device includes a disposable power cell that delivers 20 watt-hours of power and can charge a smartphone up to four times before it runs out of power according to the maker. The device has universal compatibility with included connectors for standard USB, miniUSB, microUSB, and Palm Treo as well as Nokia tips.

Medis says that the fuel cell has a DOT permit allowing it to be used on an airplane to keep your devices like iPod's charged and the fuel cell has the UL and CE marks as well. The fuel cell produces power without any emissions that cause pollution and can sit on a shelf for 18 months without activation before being non-functional. The overall dimensions of the device are 96.2mm x 67.75mm x 36.6mm after activation.

Set-up and Use
Medis says that the device will be able to provide enough power for four full charges of the average smartphone. I use an iPhone and it is the device that I connected to the Medis fuel cell for testing. Setting up the fuel cell is very easy. You simply find the tip you need (in my case the universal USB plug) connect the tip to the charge cable and then activate the fuel cell.

Activating the fuel cell is done by removing the safety strip to prevent accidental activation and pressing the pack down firmly until you hear a click. After the click you shake the fuel cell and wait a few seconds before plug-in in the charge cable and then connecting your phone.

All of those steps took less than a minute to complete and connect my iPhone. The iPhone simply showed that it was connected to a power supply and continued operating as it always does. That is all you can really expect. Medis says that you can charge the device up to four times before the fuel cell runs dry.

I rarely use all the power from my iPhone before charging it and after a normal days use for me there is typically about 3/4 of the battery capacity left according to the battery gage on the iPhone. At the end of the day, I plug the phone in to top it off before the next day and that is what I did with the fuel cell. I would bet that most people will be doing the same thing making what I did the normal usage scenario.

The fuel cell produced power for about four days and had I needed more juice from it than I use in a normal day, the extra power was there. The Medis fuel cell was very easy to use and set up and simply worked. The only bad things I can say about the device is that you can’t refill the cartridge once its empty, it has an expiration date, you have to buy a new cartridge each time you run out of power and its rather bulky. You aren’t going to slip it in your pocket for a day of hiking with your iPod (unless you have really big pockets). The starter kit I tested here retails for around $40 and a replacement fuel cell is about $25.