What the smallest solar panel to charge ...

... a Garmin Oregon 600 with their rechargeable batteries?

you might find this site interesting http://www.thewarmingstore.com/voltaic.html they seem to have a pretty good selection on solar panels, and size information for each. not covered there, is one that I'm interested in IICRC it was two small panels that used a common pencil hole to "prop up both for stationary charging. ( doing a bit if research to, once again, find the information.

I have been checking out the utube videos of home experimentation with solar cell battery charging. most of the ones I've been checking out were cannibalized from solar garden lights. ( and their battery charging control printed circuit- about 2" square- these also come with one rechargeable battery to boot!)) the cell it's self is usually about 2" square. Under ideal conditions the charging rate seems like it could fully charge two or three AA's or AAA batteries in about 7hours. seems small enough that one could sew one to a backpack and get by with it, on a multi week hike. if your power requirements matched. I'm not sure how you would go about protecting the cell from damage, other than being very careful.

I have still not found a better solution than this:
http://www.amazon.com/SUNLINQ-400mA-Portable-Solar-Panel/dp/B003M6W7XW

It is very light, and since it outputs normal usb voltage you can connect direct to a phone or ipod, or have the option to use one of those small battery packs to store power. I use a 1800 Mah stick that weighs a couple ounces. The other advantages are that it is flexible and water resistant. I used a hole punch to punch some holes in corners for pack mounting. Every other solar panel I have seen are in a heavier plastic housing, have extra weight/watt, and feel a little more breakable.

since you've indicated that you might like a storage battery to go with this, the field opens up considerably. the mfg. of this, claims it will collect 200mah from the solar panel. http://www.amazon.com/Rain-resistant-Sho...DCPRRAGBAG77VWW it's 15 square inches verses 126 square inches unfolded, one tenth the size of the one you linked. the trade off being a modest drop in output. cheaper by quite a lot AND you get 5000ma of storage. both are about .5inch in thickness (folded in the case of the foldable) size was your initial criteria

That's a nice, big battery. Looks like the solar array would take a long time to recharge it but it will keep some items charged up over a pretty long trip.

I've used one of these: Bushnell Solar Wrap Mini with good success, but its (unstated) battery capacity is much smaller, so I rely more on the solar panel itself. The brilliant bit is how small it is when rolled up for storage. Am hoping they update it with the latest tech for more capacity at the same weight and size.

Cheers,

I have been thinking about purchasing a Sun tactics model. Seems like a quality product for a pound.