Solar flashlight helps Africans

Flashlights for a worthy cause:

http://www.azstarnet.com/news/183839

Brightnorm

SolarFlashlight where it makes sense?

Hi guys,
My wife just sent me a link to This Article about a guy who developed a flashlight for people who don't have access to the grid or funds for batteries.

EDIT: if this has already been posted forgive me and my ignorance...

More info on this light from the manufacturer here and Craig's review as well.

Re: SolarFlashlight where it makes sense?

Are the AAs NiCad?

That light sounds like a very appropriate use of the technology. I think it's important to remember that for those flashlights to work as designed (or most other self contained solar devices that charge themselves) they must be used on a regular basis -- making them suitable for their intended market. They have no choice but to use them every night.

I'd expect Westerners to be very dissapointed with them for a number of reasons. Most of the complaints about solar lights, radios, etc, seem to revolve around the device not working after sitting idle for 6-9 months -- which won't happen to these lights in the refugee camps.

Re: SolarFlashlight where it makes sense?

(Moderator note: removed inactive link due to thread merge - THANKS!)

About 3 hours ago someone posted something similar, where sigman posted the manufacturer's URL and craigs review:huh:

Re: SolarFlashlight where it makes sense?

Thanks for the link. After reading the review and skimming the BoGo site I'm really impressed. I love the idea of being able to swap out the AA cells. I also like the fact that they used an LED array. This is the coolest solar light I've ever seen.

Merged threads (thanks for the link Illum!)...same articles in the links, but the one that Don posted has more info...

your welcome

Hello Brightnorm,

Thanks for bringing this to our attention.

I have been thinking about checking out solar battery chargers for some time now. This gave me an opportunity to start in a way that benefits others.

Who knows... I may find a use for the light too...

Tom

I'm one of the testers. Just like Craig, it failed the "dunk" test (messed up the switch), but otherwise performed very well in terms of charge/discharge cycling, amount of light, portability, ease of use, etc.

My intention was to ship it off to some people in Central America for them to do some extended "real world" testing, but the switch died before I could do that. Maybe the light can withstand use slight rain and/or even a downpour, but it won't tolerate more water. Resistance to humidity in the switch would be critical for these things to be relied upon in the humid tropics, and is something that still concerns me about the design.

I just read Craig's review, and I don't think I could add much more, except that I will try to break the darned thing. I really want to see how impact resistant this thing is. I'm just trying to push it to the limits to see where it might fail. So far, though, there was very little I could convey to the company in terms of improvements.

Sub, to answer your question, IIRC, they're 800mAh NiMH's. You can easily swap them for cells with greater capacity. You'd be stuck with a loooooong charging time, though.

...and since we're talking about simple lights and projects for developing countries, here's another one:
http://www.worldtorch.com/

There are some very knowledgeable CPF'ers behind that one, BTW.

Wouldn't it be better to use NiCd batteries in these lights? They will certainly be over-discharged regularly. The first person to get one will probably fall asleep with it turned on. Much of that will kill a NiMH in a hurry.

Geoff

Flying Turtle said:

Wouldn't it be better to use NiCd batteries in these lights?...

Click to expand...

My thought, too.

Sorry Sub_Umbra. Looking back over the posts I see you already pointed out the potential battery problem. Didn't intend to echo your thoughts.

Geoff

Flying Turtle said:

Sorry Sub_Umbra. Looking back over the posts I see you already pointed out the potential battery problem. Didn't intend to echo your thoughts.

Geoff

Click to expand...

Not to worry. I'm content to just not be alone. Actually, your post was more lucid than my thoughts were.

My lights arrived.

Very interesting design. I set them out in the sun for a day and got around 4 hours of light from them before shutting them off. They were dimming down and I had not equalized nor formed the batteries yet, so I just shut them off.

Pulled the batteries to do a forming charge and to check the capacity. My units came with NiCd cells, but they are printed with a message that states that they should be replaced with NiCd or NiMh cells.

My batteries are labeled as 800 mAh, and they are testing out to a little better than 900 mAh.

I went to show a friend the light and noticed a fog on the inside of the lens. The light had been sitting on the dash of my car in full sun. I opened up the head and let the moisture out. A few more hours in the sun did not see any re-occurrence of the moisture.

Using Craigs "blow" test, I blew on the switch and air came out around the edges of the battery cover. I could press on the cover and slow the air down, but it appears that this light should not be submerged.

I plan to leave mine out in the rain to see how well it does. My gut feel is that rain should not be an issue, if the light is laying with the solar panel up.

I like the "glow in the dark" gasket at the head, but the battery compartment cover is very hard to open up. The screw comes out easily, but the cover is a tight fit. I had to take a knife to work it out.

I get around 84 lux on fully charged batteries and it dims down from there. It actually started out at around 90 lux, but it dropped off rather quickly and settled down at around 84 lux.

The beam is very useful. It is similar to my 5 LED High output Peak Kilimanjaro, but the BoGo light has a lot more spill and the hot spot is a bit bigger. There are a few artifacts in the spill of the BoGo, but when reading with the light I don't notice them.

I hung the light up in a room, read a few chapters in a book, and did some sorting. There was ample light, so it seems to meet its light output objectives.

I like the concept, and the price is dirt cheap. The only issue is the lack of being water proof. Any ideas on how to improve this?

I called Mark Bent to discuss this. His wife informed me that he is in France until Thursday. I invited them to visit CPF and will have a discussion with Mark when he gets back. His wife told me that he is working on improving the light. They have several thousand lights in the field. Exxon Mobile was responsible for getting around 20000 lights distributed, and others have jumped in as well.

I think this is a worthwhile project and we should offer any technical help we can in order to improve the light.

Tom

SilverFox said:

Using Craigs "blow" test, I blew on the switch and air came out around the edges of the battery cover. I could press on the cover and slow the air down, but it appears that this light should not be submerged.

Click to expand...

Isn't Craig's test actually the "dreadful suction" test? Though whether a light blows or sucks is of little consequence, only that it does

Sounds like a really nice piece: hours of runtime with no cranking, floats, forward clickie(!). Perhaps an o-ring + rubber boot like one from a 6V lantern or Kroll glued to the body could help with the waterproofness?

SilverFox said:

I like the concept, and the price is dirt cheap. The only issue is the lack of being water proof. Any ideas on how to improve this?

Click to expand...

Ideally, you'd want a waterproof switch assembly, but from what I heard from the manufacturer, that would raise the cost beyond what is financially feasible for the project.

A simpler idea would be to make a groove on the switch plunger and place an o-ring there. That way, the o-ring would seal the space between the outer cylinder and the actual switch plunger. A couple of potential caviats I see with that approach:

- switch action may be stiffer, unless the o-ring is well lubed, but
- it'll need regular maintenance as the lube wears off

Another option would be to make a rubber switch cover. This would require a modification in the flashlight molds, etc.

Hello Bfg,

You are correct... It was a suck test.

Tom

Hello greenLED,

I will have to take mine apart to see if there is a possible simple solution.

Zip Loc bags come immediately to mind...

Tom

SilverFox said:

I will have to take mine apart to see if there is a possible simple solution.

Click to expand...

Hi, SilverFox,
Is your switch still working? Mine gave up the ghost and I couldn't get it to work again, even after major surgery. I was surprised at how quickly the switch parts corroded. Maybe coating them/encapsulating them would add an extra layer of waterproofing?