Coghlan’s recently came out with a brand new Solar Dynamo Power Pack. This is a 6000 milliamp power pack for charging your cell phone, tablet, or anything that will plug into a USB port.
There are three ways to charge it: You can charge it by plugging it into a computer or USB wall charger, it has a solar panel that can charge in the sun and about 30 minutes of charging will get you a few minutes on the phone, and 10 minutes of cranking on the dynamo will get you one minute of talk time. And you can plug your phone in as you’re charging so that your phone charges directly from the charger.
If you are looking for a super portable charger, check out the Coghlan’s Solar Dynamo Power Pack.