charging batteries on wilderness expeditions

[Tim Smith, M.Ed.]

I want to take my gl2 on some extended wilderness canoe expeditions but don’t know how I can charge the batteries. Has anyone dealt with this problem, and, if so, what are some solutions?

[Rob Lohman]

I haven't dealt with it, but a couple of obvious things come to mind:

1. take enough batteries (charged) with you, ofcourse this depends on the lenght of the shoot

2. use a power inverter to convert the 12v from your car to 110v/230v which your camera adapter can use (make sure you do not drain the car battery, see point 3)

3. use a seperate car battery to power your stuff. If you go with option 2, you might want to bring an extra one if you don't want to get stranded

4. use a solar collector to charge your batteries

It might even be possible to convert the 12v from a car battery
to something native (like 7.2v the Canon's seem to need) instead
of go like this:

car battery -> inverter (110v/230v) -> camera adapter -> native voltage (7.2v for example)

That will drain your battery much faster.

The advantage of the car's battery that is inside the car is that it
gets recharged when you have the motor running (not 100% sure
on that) and definitely when you are driving around.

[Tim Smith, M.Ed.]

Thanks for writing. I'm referring to a trip in excess of 2 weeks (up to 4 weeks) with no automobile support. Thus no ability to charge from a car battery. I've heard of flexible solar panels that people use to charge laptops and satellite phones, but would like to hear if anyone has used these and how they hold up. Also any other possibilities that people have heard of.
I currently carry 3 BP-930 batteries with me, but plan to add 1 more for longer trips.

[Bret Corbin]

Someone else asked this question a while back and it launched me into research mode. That person decided to buy more batteries so I never posted what I found.

http://www.cetsolar.com/deltacharger.htm

has product(s) for solar charging batteries. The one at this web address has a 12v (cigarette lighter socket) output so you could buy a battery charger for your batteries that can charge from a car's cigarette lighter. These need direct sunlight to be effective. Also the panel in this link is only 4.5 watts so it would need to be determined how much daylight is required to charge your batteries. This same company does have other products that are higher wattage.

Good luck and let us know if you find a solution here that will work for you

[Greg Patch]

Howabout a small honda generator, I have one that is pretty small that would surely fit in a canoe...If you only ran it long enough to charge batteries it might last the whole trip....

[Mike Cook]

I do this on extended backcountry board trips. I jurry rigged multiple solar cells (flexible and expensive) to a simple voltage regulator and powered the 12v charger with that.

Two things. You need plenty of cells and use all your daylight. I ended up taping the solar cells to my pack everywhere I could and left them charging all day.

Seemed to work fine and things held up OK. Had to keep splicing wires but thats just from the half-assed way things are taped to the pack.

[Hagop Matossian]

A good friend of mine (veteran ethnographic filmmaker Mike Yorke) makes a lot of films in India & The Himalayas. He uses Solar Cells strapped to the top of his backpack, as Mike Cook suggests, as his exclusive power supply.

The results of his most recent escapade are online at http://www.undeadarmy.org/video.htm
direct link http://www.undeadarmy.org/videos/HolyMan_big.wmv
I edited it.

An alternative for cloudy conditions is to build a charger that will create current from your own kinetic energy. This involves wrapping copper wire around a hollow plastic donut shape, and placing a ball bearing in the donut. The movement of the ball bearing will create a current in the same way as a traditional dynamo. Rough instructions I know, but hopefullly will get you started!

Hag[]p

[Mike Rehmus]

If money is no object, you might want to look into a Stirling powered generator. I think Philips made one a decade or so ago that was very simple and generated AC current.

For those that don't know, a Stirling engine runs on hot air. Yes, one end of the engine is heated and the engine runs fairly well. Around 1900, Stirling powered pumps were used to pump water in homes. The last big commercial use of Stirling engines was in fans. A kerosene lantern type of burner would provide the heat and run a fan blade set of around 18 inches or so. Last made in Pakistan in the 1980-90's.

As energy gets more dear, we will see the Stirling make a comeback as it can run nicely on waste heat.

[Jacques Mersereau]

The solar thing sounds great but has the caveat, no sun = no power.


I hate the idea of having to burn gas if solar would work and do the job,
but the little Honda or Yamaha genny is the most reliable way to go.
I would buy an extra charger or two so that
when you fire the genny, you can charge two or three batteries at the same
time for maximum efficiency.

[Hagop Matossian]

Wow, I never heard of a stirling generator before. Sounds like a great application for biomass fuels, altho I'm sure it must require regular cleaning.

[Mike Rehmus]

Nope, a Stirling is pretty much a closed system so the internal air doesn't become contaminated.

http://science.howstuffworks.com/stirling-engine.htm will give you a brief overview of this technology. The links should take you to some other interesting places.

Somewhere in Scandinavia, is a 200 HP bus so one can get power out of the technology. These engines don't have a high specific output unless they get exotic.

But Sweden makes Stirling engine-powered submarines so they are used for 'real world' applications.