peace core and solar battery chargers

I have a friend who is going into the peace core in Africa and the people she will be living with will probably not have electricity.

She hopes to bring a radio and a light to read by, but will probably not be returning to the states for 2 years. I would just get her a head lamp, and one of the CMG ultras, but both of these things need batteries.

Can anyone recommend a battery charger which doesn't need mains power? Probably solar. It needs to be able to robust to last 2 years outdoors, and effective. I would prefer to buy a smart charger which would not overcharge batteries. I don't want to buy a toy.

Brunton Solar Roll-14. Rolls up to a 12"x3" cylinder and fits in an included tube. 14W of power. laminated for durability and definitely not a toy at $399 list price. I've seen it almost $100 lower but it's tough to find in stock. This thing can charge car batteries, cell phone, power laptops etc. Cool and tough but pricey. Maybe you could take a collection among friends and family or something?






Tad

If the Solar Roll is too much. Brunton also makes the Solar Port 4.4 which doubles the wattage of the older 2.2 at only slightly larger size. It provides 4.4W to charge portable devices (has a vehicle socket in the hinge as well) and includes an AA battery charger for a $120 list price.





You can go to www.brunton.com to see all the specs and their full line of portable power options including storage cells.


Tad /ubbthreads/images/graemlins/grin.gif

Here are some threads from the beging of last year that covered a lot this.

Need a bright light for Africa

...picking AA LED lights for Peace Corp

hope it helps. /ubbthreads/images/graemlins/smile.gif

CCrane has a smart battery charger that can use 12V and NiMH batteries. Lots of solar dealers sell them, and there are lots of solar panels out there to make the 12V. A small Morningstar or BZ controller (8 amp or so) can hold the voltage to 14V.

She might want to have a small solar system shipped to where she's going, if that is possible. It could be cheap and give power to a community center. It would be a nice thing to leave to the people when she leaves.

Type "solar charger" into froogle.com and you should find tons of those folding Brunton things under various label for around $60, and some similar ones in the $30 range. www.thomas-distributing.com sells some, as I remember.

You can also get her a box of 40 or 48 AA alkaline cells for $10 or so. A box or two of those is probably enough for two years, if all she's running is a small LED flashlight and a radio. You might get her a regular CMG Infinity instead of an Ultra, since they run for about 2x as long on a battery, and still make enough light for most things an Ultra is good for.

Finally, it's likely that she'll be able to get batteries there, though they tend to be awful-quality zinc-carbon ones. They should still be ok for running an Infinity or a radio, as both devices use very little power.

An interesting problem. One I've been thinking a bit about as it turns out. Some sort of solar system seems right, although there are some serious constraints on size. If you want to run your Maha 401 you'll need a two square foot (10 Watt) panel, costing $100. Charging a single AA at a time only cuts that need to a few watts. Each AA cell is good for two or a bit more Watt Hours. If you want to charge it in less than two hours, you'll need to put at least two watts in to do it. Dem's the rules. Nothing's free.

OTOH, it should be possible to charge a small number of cells slowly with a much more modest panel. In fact, in this small world of ours, I was out yesterday about three in the afternoon for a quick check of two small solar panels I got for just this purpose.....in Berkeley no less! Honest. Specifically, I bought Silicon Solar's "EpoxLite Solar Panels", Since they feature robust design (unbreakable and weatherproof) they seemed like a good starting point. First quality, single crystal cells. I bought 4V, 250 mA and 6V, 150 mA panels to test. $15 each, which is also inside my price window.
Silicon Solar
Perhaps something as simple as a battery holder and a resistor would complete a basic system ('fill the holder, put it in direct sun for two days....'). It may, however, turn out that NiMH is not a good option (unless we can control charging), and use of NiCd is indicated. This may be found acceptable in the end but it does mean the cells at least will need to come back for proper disposal.

As Paul has so correctly pointed out, the best 'single user' solution might be a box of AA cells. And this is not the dark side of the moon, AA and D cells exist 'everywhere' (and have for some time), but the cost is high and performance low. For that reason, I'd expect any small system you send to be used by as many as possible for it to support charging batteries. The 'full kit' might include two dozen (or more cells), the locals are sure to find a use for them.

Anyway, I'm in Berkeley and working on the same problem. Send me a PM, let's link up?

Doug Owen

This is just off the top of my head, but if there will be vehicles with 12-volt batteries, what about one of those solar car battery chargers combined with one of those Ray-O-Vac 15 minute NiMH chargers with a car cord? Perhaps a spare automotive battery would be available to use to charge the Ray-O-Vac iC3 batteries, and the solar car battery charger could be left hooked up to the car battery all the time to keep it topped off.

I didn't see any requirement to charge the batteries in two hours, and a Maha 401 is way overkill. Those $30 solar chargers (they are just a box with some solar cells and a blocking diode direct charging the batteries) will fully charge four AA NiMH cells in maybe 2 days. That should be enough to run a radio or LED flashlight for several weeks of normal use. With one or two spare sets of batteries that are kept charged, I don't think any more charging capacity than that is needed.

Any solar panel that puts out less than 100ma also won't need regulation to avoid overcharging the NiMHs. I like to stay below 5% of capacity rating but most manufacturers allow as much as 10%C. And note, a solar panel rated 150-250ma may only rarely exceed 100ma depending on many variables. For example that 12" x 3" panel rated 14w is beyond belief. You'd be lucky to get 14w with a square foot of solar cells, especially the amorphous types. This one might be 3-4 watts if it ain't cloudy at all.

Russ, the Solar Roll is actually 12"x 57" unrolled, it is only 12"x 3" rolled up for storage. It's flexible and waterproof, and thin like a mat, with grommets to tie or screw it down. You can also link together panels for more power. The 4.4 Port can be linked together with others too. All of them come with various interfaces to charge or run different types of electronics too. They make a 25W unit that triple folds into the size of a laptop computer as well.

Tad /ubbthreads/images/graemlins/grin.gif

How about a radio or light with a wind-up generator? I bought my Mom a Freeplay radio (www.freeplay.net) a couple of years ago to use during power outages, and she uses it almost every night - she cranks it up before going to sleep and has no worries about leaving it run. There's no batteries to run down or electricity to pay for. Her radio isn't the most robust, but you might be able to find other manufacturers that have heavier-duty stuff. Freeplay also makes wind-up lights, but I've never tried one. Another thought for a light would be one of those Forever flashlights that you shake (no experience with those, either, though).

- Dwayne

I was in an airport recently and stopped in at this 'got to have' store. the pocket shortwave radio I almost got, but the radio/light/solor/crank/AC thing looks good, and the solor/crank/AC multi-band looks neat also.

http://www.hammacher.com/publish/65939.asp?promo=electronics

.02

Jeff

While looking around I found an old solar charger sitting in a drawer. It was doing no good there, so i gave that to her along with a 1 watt 3AA flashlight that elektrolumens used to sell.

The elektrolumens light will go along with the other lights which people have given her, but when she turned that light on inside, she said "wow" which made me happy.

The solar charger I gave her will charge 4 batteries in 14 hours of bright sunlight (I assume NiCD batteries, it is that old) so NiMH in 3-4 days, ie trickle charge strength, so she will not fry them. I am also supplying her with a bunch of AAA NiMH batteries for the rest of her hardware, though I heard that she has 2 48AAA packs already in her luggage.

For news, she is planning on getting satellite radio. Though something which just occurred to me, and I haven't checked up on... Is that just one satellite? maybe in geo-synchronous orbit? Will it even work in Africa? I will check out the short wave options too.

Did you really mean to say NiMH AAA and 48 AAA's? She really has all that AAA stuff, not AA?

Either way, better test that solar charger with the NiMH cells BEFORE she goes off to Africa relying on it. Put some flat cells in it, charge them up for a couple days, and make sure they'll run a flashlight for as long as you expect.

Satellite radio sounds a little bogus to me, and expensive. She should be able to get news from a shortwave receiver (a decent one, not one of those dinky pocket ones) with a reasonable antenna. For antenna, she should try to string a 50 foot or longer piece of wire through the air, e.g. tie one end to a tree and bring the other end through the window to where the radio is, keeping it taut so it's several feet off the ground. That will work much better than a typical receiver's built-in whip antenna. She may want to add an antenna tuner (adjustable coil) if the receiver doesn't have one built in. I'm getting bit out of my depth with this though, maybe someone else here can say more.

Finally, here's a real simple solar flashlight. I always thought these things were kind of gimmicky, but maybe you've found one of the situations where it makes sense:

http://www.countycomm.com/swisslight3.htm

If she clips it to her belt loop and wears it all the time, it should stay charged up from the daylight it receives, and she'll always have it handy. Really though, as we found from that guy whose son went to Costa Rica, a CMG Ultra will run for months of normal use on one alkaline AA, so a box of 48 AA's will be enough for many years, and the Ultra is bright enough for most purposes.

You know, giving this some more thought, the whole solar thing and the idea of bringing a ton of batteries all seem silly.

Solar charging depends on outdoor sunlight, which means leaving the equipment where it could walk away easily. You could do it in more time with a sun-facing window, but such a window may not be available.

Bringing a ton of batteries is pointless too. She'll have some contact with civilization, and there will be batteries (zinc carbon) available locally. The only probs with them are leakage and low current capacity. So the solution is pick low-current flashlights and check on the cells every so often and change them if they're going flat and getting ready to leak. Sure, bring a box of alkaline AA's for good measure, but don't go overboard.

Lights I'd take:

1) CMG Infinity (not Ultra) on neck lanyard, this should run just fine on a zinc-carbon cell. In fact, putting a lithium cell in it before leaving may be enough for the whole trip. Somebody claimed these lights run 80 hours on a lithium but I doubt it. Should run 20+ hours on a zinc-carbon. Warning, this model may be about to be discontinued, so if you want one, get it now.

2) (optional alternative to Infinity): CMG Ultra or Ultra-G, brighter but less runtime than above. Will probably kill a zinc-carbon cell in a few hours.

3) UKE 4AAA eLED, $20 at Brightguy. Somewhat brighter than a Minimag, rugged and waterproof, regulated to get best use of the batteries, underdriven Luxeon LED won't burn out. This light just came out and looks like a great buy. I think it solves the fairly-cheap-rugged-AA-light problem once and for all. This too should run ok on zinc-carbon for several hours.

4) 4D floating lantern with a bunch of spare XPR113(?) bulbs, for occasional use when something bright is needed.
Send some alkalines with it since it will use up zinc-carbon cells pretty fast, but runtime probably won't be too much of an issue the way these things are usually used, just a little bit at a time.

If she gets a Sat phone then she is going to need a good source for charging. I am pretty sure Sat phones have more than one Sat relay these days as they are in use all over the planet, by militarys and news crews etc.

Solar chargers are pretty efficient now and don't usually need full sunlight to operate. I know the Solaroll will fully charge a cell phone in about 45min.

Tad

Of course solar cells don't need full sunlight; they just produce a lot more power with full sunlight than with partial sunlight. The Solaroll is IMO way overkill for just charging a few cells for flashlights and radios too.

Satellite phones are pretty expensive but if you're only going to use one once in a while (powered off when not in use), then again, a few nimh cells is probably enough. Just keep a set charged up in case you need to use the phone. If you power up the phone if some situation requires an outgoing call, and maybe power it up for 30 minutes a week to receive possible incoming calls, again, a couple of those portable NiMH chargers should be enough to keep you covered.

It looks like you can get an Iridium phone on Ebay for about $1000, with prepaid airtime costing $1/minute in 300 minute increments with 1 year expiration. So for two years you'd have to buy 600 minutes, or 6 minutes a week. I guess that's about right to make a weekly 2 minute status call, and have an occasional longer conversation.

My mental image of this situation comes from TV shows and may not resemble reality, but I'd guess the satellite phone isn't really needed. Wherever Yeti's friend is stationed, stuff like food supplies have to be coming in from somewhere, probably from someplace where there's a phone and a fax. So there's probably some way to get an occasional letter mailed or faxed back home, or a phone call made if something urgent comes up.

Where are you guys getting Satellite Phone? I am talking about a Satellite Radio. A Satellite radio has $7-$10 a month subscription several hundred channels commercial free. It recieves, but doesn't broadcast. Africa shares a geocyncronus satalite with europe. The US version of this is the sirius radio, see here:
http://www.siriusradio.com/

Yeah, satellite radio is different than satellite phones. For just getting news broadcasts and having something to listen to, I think a shortwave receiver is better. Sirius Radio has always seemed to me to be too much of a yuppie toy. Also, the satellite receiver probably uses a lot more power than a shortwave set.