Pre walk
The "SILVERPOINT Solar Trio" Solar Charged LED Torch (1) will be used as my light source, saving weight on carrying a separate torch. It will be positioned on top of my sack and will charge its own 7oomAh/4.8v internal battery in daylight hours. It's power, via lead (6), can be used with adapter (4) to charge my phone (3) which is also my MP3/radio. It can run my GPS (2) direct via USB connection or charge spare AA batteries (5) for its use.
Whilst never an ideal energy source ( power to weight ratio ) compared with taking quantities of high capacity batteries, I am persevering with the "alternative technology" tack as it potentially offers the benefits of longer periods of autonomy. This will inevitable lead to investing in lightweight thin Powerfilm technology.
Shortly before leaving I adapted the Solar charger into a higher capacity more adaptable unit. The casing was taken apart and the batteries substituted for four removable high capacity AA rechargeable. The bare unit was then placed in a small water proof pouch. The benefits being the obvious higher capacity storage, the charged batteries could be used in my GPS and it was possible to make sure the unit was fully charged before leaving by using a mains charger. The whole thing weighed no more than the cased original , achieving a better power to weight ratio. The total number of batteries taken were 6 AA's.
Post walk
There was always going to be a shortage of power using this system but I admit I did not perceive to run out so drastically towards the end. The GPS batteries lasted till about day 6 where they had to be rotated regularly as they were not charging thoroughly. Charging my phone took it's toll on the batteries and during the last 3 days my phone was dead and the GPS would stay on for about 2 minutes, before cutting out, every battery rotation. As I lost my map on day 10, navigation proved problematic and it's a miracle I made forward progress but I love a challenge and this made it thrilling to the very finish! A better more reliable power system is needed for any future outing.