Sorry about the late post on this, I have a Steripen solar charger and it takes forever to recharge. I would recommend getting a fold able solar cell off or e-bay of 20 watts or greater. If you have time, click on the link below and watch the videos, it will explain what I am talking about. There is alot of useful things you can do with solar. I would also recommend a hand pump filter with a carbon filter for example
I use a steripen and a katadyn combi filter.

The reason for the katadyn combi filter is to get rid of chemicals and pesticides from the water, the steripen kills all the viruses and nasties. Now a days with the water supplies. there is high traces of pesticides and pollution in the waters around the US and boiling water and tablets, etc.. won't get rid of chemicals out of the water systems, carbon helps remove some of these chemicals out of the water. If you have a 40 watt or greater solar cell, you can run a steripen or Miox 100% without any batteries in an emergency. I love the steripen for it's purpose but it's all in your preference. Watch the video and see what you think.

Click Here and watch the video
http://forums.equipped.org/ubbthreads.ph...true#Post126059