Solar Power Battery Charger SP3000

I know next to nothing about them but I see that after the first charge (6-7 hours by AC) it takes 25 hours of sunlight to fully charge.
As far as I understand the AP is not exactly the sunniest trail around but since every few days you can go to town maybe a few hours in a power outlet will top it up…
BTW, solar panels need to be pointed pretty much straight to the sun not just in the general direction or the other way.
Franco
Maybe I am far too subtle but the angle comment was to highlight the less than ideal angle one would have walking on a trail with a panel stuck on the pack …

"BTW, solar panels need to be pointed pretty much straight to the sun not just in the general direction or the other way."

Yes and no. Most solar panels are used in a permanent mount on a building roof. They can be aimed at the south (assuming northern hemisphere), and noon is when they will collect the very best power. However, they will collect fairly good power from 10 a.m. until 2 p.m., and they will collect a little even beyond those hours. Assuming a sunny day, you expect to get less than six hours total of "full sun."

A few solar panels are permanently mounted with what is called a tracking mount. This is a big pivot mast that orients the panel toward the sun. This helps, but it also consumes power and costs money.

A moving backpacker has a slightly different problem. If he is moving away from the sun, then he can hang a panel off the top and rear of his backpack, and that will aim it somewhat at the sun. But then with turns in the trail and tree cover overhead, this becomes complicated. A camped backpacker can use a solar panel more like a permanent mount on a building. However, most backpackers are moving during the best sun hours of the day, and they are camped during the worst sun hours. Solar power in a "base camp" situation is OK.

If I am heading along a trail, I would hate to have to concentrate on whether I should lean to the right or left to collect better sun on my panel.

–B.G.–

Do they make some kind of adapter. Maybe a battery powered charger that takes C or D battery's that charges a cell phone.

And I plan to go to the great smokey mountains part of the trail. Has anyone ever been?

Good luck with that one unless you only plan to turn your phone on for a few minutes a day. You will need a charger with much more real estate to harvest any real power. The 25 hour charge time is under ideal conditions you will rarely see while hiking. The sun must be out, you must not be in even partial shade, and the panel must be oriented toward strong sun at just the right angle. How many hours a day do you expect to see all those conditions? I tried a panel much bigger than that and it just didn't work. I suggest a charger powered by AA batteries or a dedicated USB power pack. Try Dealextreme.com for some ideas.

I carry an extra battery pack that recharges my iPhone twice:
http://www.jameco.com/webapp/wcs/stores/servlet/Product_10001_10001_2110414_-1

I'm not at all happy with the options for solar. They all weigh a lot. Will probably make one…

THIs is kinda off topic but is there and guildline or criteria you have to meet to get a backcountry permit for the great smokey mountains?