Cheap Solar chargers

[Steinberger]

Hello everyone, I am 16, new to Hiking HQ, and pretty new to hiking. I have been starting to do some longer weeklong trips in the backcountry and am eventually plan to do the AT. I like to have luxuries gps, cell phone, lights(I know a lot here has had a battery run out in a flashlight at right at the worst time), and maybe an mp3 player without bringing a ton of extra batteries but I also can't afford these expensive and very bulky, heavy, and delicate solar systems to recharge them so I looked around for some cheaper, smaller, and lighter alternatives. I thought I'd share some of what I found.

http://www.solarworld.com/batterychargers.htm

These seem to be the smallest solar chargers around for the price, even though you sacrifice a lot with an 11 hour charge time, it's better than nothing when you need a new battery in you light or need to use your phone when you break you leg or something like that. The SPC-4 looks very promising but the SPC-1AA could fit in pretty much anybodies pack with out to much fuss.

http://store.sundancesolar.com/sobachfor4aa2.html

Heres a slightly beefir version of the last one with a water resistant cover charge meter and skightly faster charge time.

http://store.sundancesolar.com/siflsochfora.html

These look like a great alternative to the more expensive flexible solar panels but would require some work to make the water resistant.

I am going to try out one of these some time.

[dropkick]

Over the last few years I've I purchased a few solar chargers (2 of them from Sundance Solar - 2 of Steinberger's links above), but what I now use for hiking is a very basic charger I built.

I have to be careful not to overcharge and I have no meter, but it very light and has worked well for me. (If you overcharge batteries the will get warm and may lose some life - if you really overcharge they get very hot and die - with a solar charger this usually requires at least one sunny day or more of overcharging)

My charger will do 2 batteries from dead in 5 to 10 hours, depending on sun.
- I now use Ni-Mh batteries instead of NiCads and as I no longer have to worry about imprinting I normally top off the battery charge daily.

I used 4 flexible cells linked in parallel and hooked to a Radioshack aa battery holder. I taped the cells to the inside of a plastic bag with scotch tape, and then taped a safety pin onto the bag with duct tape.
The bag provides weather protection and the safety pin provides a way to attach the bag to my pack.

Quick, simple drawing - I need a digital camera...
http://hikinghq.net/forum/attachment.php?attachmentid=188&stc=1


These are the type of cells I used (though I bought them through eBay).
-I have delt with this seller before (Texas Solar) and like them.
https://www.shop.texasolar.com/displayProductDocument.hg?productId=43

battery box:
http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=270-408

[Steinberger]

That sounds great. If you can get a charged battery in 7 hours that is excellent. I wonder if your could use solder trace wire to the parallel panels like you said and the put the whole thing through a commerical laminating machine without damaging the panels? The you could just fold it like an accordian when you pack it up. You could even do another set beside it and fold it like a map. The idea of multiple small panels looks more promising now than one big one.

[Steinberger]

One other thing I forgot to ask. Do you know if hooking it up parralel increases the voltage or amperage?

[Hog On Ice]

parallel increases the amps - series increases the volts same as with a battery

[Steinberger]

Thanks. I am going to look into laminating a solar pannel and see how it turns out.

[blackdog]

A cranked generator might come in handy (no pun intended). Something like...

http://www.thetravelinsider.info/roadwarriorcontent/images/SideWinder.jpgThe Sidewinder (http://www.thetravelinsider.info/roadwarriorcontent/sidewinder.htm).

A small single-wing rotor (one-piece blade/counterweight) to replace the crank might be something to experiment with as well.

[Lanthar]

Unfortunately, that crank operated is only for cell-phones. You're right though a crank-operated AA charger could be very nice.

[titanium_hiker]

what about the guy who makes hand crank radios? isn't he working on some system that gives you an mp3 player powered by you footsteps?

[Steinberger]

In all truth. I don't think it would be that hard to convert to an A cell battery charger because it looks like it has a power plug to it. If what I am understanding from other sites you can make a charger bysimply wiring battery clups to a modular jack if the volatge isn't too high. The only problem is knowing when to stop charger so you don't blow up the battery and the fact that even though it puts out 300ma that would probably take you atleast 3 to 7 hours to charge from what I am guessing. Would not be bad at all for emergencies but I couldn't see spending all my free time winding a crank for GPS for five months on the AT. Still definately worth looking into though, and there is really nothing to lose if it indeed does have a modular jack which means if the charger didn't work, cut you losses plug in the phone cord, say oh well and forget about it.

[john pickett]

Dropkick,
Did you say you bought those charger panels from Texas Solar?
I e-mailed them after checking the site and couldn't find anything about sales to the public.
John Pickett

[SGT Rock]

I just read something this last weekend about putting solar chargers in Cuben fiber for some space project. Imagine that for hiking - a cuben fiber tarp that recharges your batteries.