Generating power for charging during backpacking

[TTT]

I would very much like to have a 12V powersource out in the wild. It does not have to be all that powerful, just charge batteries.

The thing is, on most of my hikes there is a lot more chance for wind than sunlight, meaning that solarpanels are a bit useless.

Does anybody make either a compact windgenerator for 12V or perhaps a handcranked generator?

What is needed to create such a generator myself, i.e. how do I turn muscular effort into electricity?

If you are familiar with the Rjukan raid / heroes of Telemark (bunch of guys blew up the heavy water facility in an attempt to stop the Germans building the atomic bomb during WW2.) you might know that they used a handcranked generator to charge the batteries (for a navigation system on the ground for bombers). This version was however too hard to crank, so hard they could not manage to turn it. Really clever :thumbsup:

 

[GPB]

The local Target here has a hand crank flashlight that also has a 12 volt power receptacle so you could charge anything that plugged into your car power plug with it. You might have to crank forever, but its a novel idea.

 

[TTT]

I live in Norway and Germany, so no Targets here...see that they got a webshop but there is hardly any descripton on the flashlights.

I do not want a crappy tiny cranker, I want a solid and effective device. I can deliver about 200w/h on a bike (the body actually "consumes" about 1000 watts, but it is rather inefficient).

I have seen an educational crank-generator delivering 12V and up to 25 watts. I could probably manage up to 40 watts without it getting too heavy.

I have found an old US Army crank-gen but it is made for 24V....and it is very large :thumbsup:

 

[Marduke]

A true wind system would be bulky, but I've heard of one idea that may work. I've never actually seen it done like this, but they make string pull chargers which could be rigged to work with wind power. Each yank on a string turns a small generator. DX even has a very small flashlight like this, and it's one of the designs used for the OLPC project (One Laptop Per Child). Anyhow, if you tie this string to a branch or small tree (while anchoring your generator end of the setup), the back and forth movement of the tree works your string generator, and produces power without further involvement.


Done right, you could set it up at camp in the evening, and have fully charged cells by morning.

 

[jzmtl]

That sounds interesting, you can put it in your backpack, and tie the string to your shoes, and generate electricity while walking.

 

[j2coe]

freeplay makes a hand crank 12v generator slightly larger than fist size with a cigaret lighter type plug on a cord for about $30 US. it's more for backup and providing power directly like for a cellphone while cranking than recharging though.

 

[paulr]

1 horsepower = 746 W, and a top athlete working strenuously can put out a few hundred watts.

Why do you want so much electrical power? Go backpacking to enjoy the outdoors. Leave the TV set, microwave, and electric clothes dryer at home . Have a flashlight or headlamp powered by an AA cell, similarly with a GPS powered by two AA's or AAA's for a few minutes a day, carry some spare cells, that's about it. Even for a very long trip, a small solar charger should be enough to keep some spare cells charged.

 

[adnj]

I agree. Today's solar cells are efficient enough to generate electricity with ambient daylight. The trick is to keep the panels exposed at all times. I've seen panels attached to the rainfly of tents and backpacks.

Otherwise, look for the Toshiba fuel cells. They'll convert alcohol directly to electricity and you can change the voltage with a buck/boost circuit.

 

[j2coe]

that might cut into the beer supply and noone will go for that