[donjoe]

Also, most portable devices on the market won't provide you with enough power for charging electronic devices in cloudy conditions.

My ideal combination to cover about 80-90% of power needs whilst camping/hiking/cycling would be a combination of water turbine (for rivers or tiny streams) and solar.

In case I'd be hiking in an area with no water supply, I'd consider something like a wind turbine. Yet, I wouldn't know why I would want to hike in an area with no water supply ;-)

[causality0]

I'm surprised they don't sell some kind of reciprocating dynamo-type thing for hikers to strap to their knee to charge while walking.

[shard]

Doesn't that just increase resistance to your walking, thus is equivalent to you converting calories to battery energy? Wind and solar would be additional energy over what you brought as stored calories or food.

[rowanajmarshall]

Going by a random Reddit thread [1], it takes less than 5 calories to charge an iPhone. I think that kind of device is already on the market though.

You're not gonna power a heater or aircon through body movement, but devices should be fine.

1. https://www.reddit.com/r/theydidthemath/comments/693daq/comm...

[Dylan16807]

It's just a unit conversion, you don't need to cite reddit.

A Calorie is slightly more than a watt hour.