On 29/10/2017 19:28, sms wrote:
> My wife and daughter are going on an Inca Trail trip to Machu Pichu next
> year.
> 
> What are some ways to manage the lack of any way to charge devices along
> the way?
> 
> I can give them some USB power banks, though these are rather heavy to
> carry and the losses to charge one battery from another battery are
> significant.
> 
> From what I've seen of the hand-crank USB chargers, they are really not
> practical, you'd have to stay up all night cranking just to charge a
> small battery.
> 
> There are some small solar panels that hang on a backpack, that claim to
> deliver 500mA of current, and that are about $100. These could probably
> charge a 1200mAH battery in five or six hours.
> 
> There is a wood-powered USB charger, but I don't know if it's possible
> to find fuel along the trail. This would be good to use at night, since
> solar obviously won't work.
> <https://www.bioliteenergy.com/products/campstove-2>
> 
> Or I can just buy them four or five spare camera batteries each. These
> are for compact P&S cameras, not for SLRs, and after-market batteries
> are $10 each.
> 
> Has anyone here come up with a good solution for trips of several days
> where they will not have any access to electricity?
> 
> The other suggestion I made is that we resurrect one of our many old P&S
> film cameras and that they take a bunch of film.

Here is an idea. Think out of the box.

http://www.dailymail.co.uk/sciencetech/article-2889932/These-shoes-...

What works for a phone will work for a camera, with some adjustments.
They will be doing a lot of walking right?