SteriPEN Solar Charging Case
This system is great in theory but falls far short in real life function.
The night before I went out for a weekend of canyoning I charged the batteries to full charge with the wall plug adapter then mounted the solar charger on the top of my pack with velcro to ensure it would always be in the sun. After hiking most of the day I came to a spring fed watering hole and a chance to try out the purifier. with great frustration I was only able to purify 2 liters of water before the batteries died. (Streipen says it should do over 30)
From what I've found out this is a common problem that is helped by changing to better batteries. If you use the Steripen always carry a back up system.
When it works it's great. The rechargeable batteries are a piece of crap. I bought an extra set of rechargeables and did not get 5 liters out of the bunch. Next time I go I'll take disposable batteries and some chlorine drops.