Is this truely Solar Powered? (dx keychain light)

Crenshaw · Jun 16, 2008

I recently bought this

http://www.dealextreme.com/details.dx/sku.13088

And would really appreciate if someone with more technical knowledge then me could hazard a guess if theres a chance this thing can be operated by solar power.

Yes i KNOW there are coin cell batteries there, but is there a chance this batteries can be recharged by the solar panel?

there was some speculation that because the Current produced by the solar panel was small enough as to be able to "recharge" primary cells.Or possibly the coin cells are of a rechargable kind?

Here you see it with a DX fauxton. Its very bright, even if it wasnt solar powered, its still not that bad.

And the GUts

Crenshaw

Daniel_sk · Jun 16, 2008

The coin cell is marked as "LIR2032", this is a li-ion rechargeable - so yes, it can be recharged. There are spec sheets on google if you search.

http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2420

http://www.powerstream.com/p/Lir2032.pdf

Jarl · Jun 16, 2008

Why the diode?

paulr · Jun 16, 2008

Yes there's a similar light called the Freelight or Swisslight (made in Switzerland) that's been reviewed here a while back. This DX thing is a much less expensive semi-knockoff with fewer features. The solar cell looks about 20x40mm which should produce enough power to recharge the battery in a day or so of sunlight if you clip the light to your backpack or maybe a zipper pull. Might make some sense for a very long hiking trip, except that model appears momentary-only and not well-enough built to really rely on. Even the Swiss one was a bit dubious. The concept is nice though.

You might also look into the Photon Rex which recharges from an external dc source, such as an AA cell that you could charge with a solar charger.

Crenshaw · Jun 16, 2008

Daniel_sk said:
The coin cell is marked as "LIR2032", this is a li-ion rechargeable - so yes, it can be recharged. There are spec sheets on google if you search.

http://www.batteryspace.com/index.asp?PageAction=VIEWPROD&ProdID=2420

http://www.powerstream.com/p/Lir2032.pdf

thats great! thanks Daniel

thanks for the input guys, i dont really need a small rechargable light, it jsut that this seemed like interesting thing to have, a solar charger+battery+light unit all in one, for a very small price. Imgaine, small giveaway baggies at "green day" roadshows or whatever would have these inside.

Crenshaw

raiste · Jun 16, 2008

Jarl said:
Why the diode?

I think it prevents the battery from discharging into the solor cell(s) when there is not enough light present for the solar cell output voltage to overcome the battery voltage.

Jarl · Jun 16, 2008

raiste said:
I think it prevents the battery from discharging into the solor cell(s) when there is not enough light present for the solar cell output voltage to overcome the battery voltage.

That'd make sense. Thanks!

LED-holic · Jun 16, 2008

crenshaw - which one is the solar powered led and which one is the fauxton in your beam shot photo?

Also any size comparison photo? say to a AAA or AA?

Crenshaw · Jun 16, 2008

hmmm on the left is the 3x 5mm led solar light...

size comparison, its quite big for a keychain light. Did you by any chance buy the "keychain" universal remote control? its about that size, just thicker...ill take another size photo with my NDI when i get home tonight...

in the meantime you can use the blue microfibre cloth's little squares to figure out a scale..:nana:

Crenshaw

Omega Man · Jun 16, 2008

Thanks for posting about this Crenshaw, I have about 3 of those solar keychain lights on my DX wishlist, and have been wondering about them.
Anyone think keeping one on your dashboard would damage the light rather than keeping it constantly charged?

swxb12 · Jun 16, 2008

OT: So if I keep charging up the LIR2032 in my crank light, will I have guilt-free lumens in my Photon?

Crenshaw · Jun 17, 2008

Omega Man said:
Thanks for posting about this Crenshaw, I have about 3 of those solar keychain lights on my DX wishlist, and have been wondering about them.
Anyone think keeping one on your dashboard would damage the light rather than keeping it constantly charged?

there was quite a bit of speculation on the product board too...i just wanted to know very badly..

i have three of these now.

swxb12, probably? its like a smaller version of the rex really..

Crenshaw

Fallingwater · Jun 17, 2008

swxb12 said:
OT: So if I keep charging up the LIR2032 in my crank light, will I have guilt-free lumens in my Photon?

You will have a dead crank light.

The vast majority of LIR2032 crank lights (possibly all of them, not sure) have no charging hardware; they just hook the cell to the little motor that makes the power, without anything but a diode bridge inbetween. And inbetween the cell and LED(s) there's just a resistor or three, or possibly some components for multimode operation (it's unlikely they control cell voltage though).

As you may know, LiIon cells are very sensitive to overcharge and overdischarge. Crank too much and/or run the light flat every time and you'll kill its cell quick smart; many people complain of not getting more than one cycle out of their crank lights before the battery dies.

There are two solutions to this problem.
1) get a LiIon crank light with proper charging hardware monitoring the cell, if one even exists;
2) get a NiMH-powered crank light. NiMH cells don't particularly like rough treatment either, but charging too much or running the battery flat every now and again is not death on a stick to them the way it is for LiIon.

Some more info in this thread I opened some time ago.

Crenshaw · Jun 17, 2008

Fallingwater said:
You will have a dead crank light.

The vast majority of LIR2032 crank lights (possibly all of them, not sure) have no charging hardware; they just hook the cell to the little motor that makes the power, without anything but a diode bridge inbetween. And inbetween the cell and LED(s) there's just a resistor or three, or possibly some components for multimode operation (it's unlikely they control cell voltage though).

As you may know, LiIon cells are very sensitive to overcharge and overdischarge. Crank too much and/or run the light flat every time and you'll kill its cell quick smart; many people complain of not getting more than one cycle out of their crank lights before the battery dies.

There are two solutions to this problem.
1) get a LiIon crank light with proper charging hardware monitoring the cell, if one even exists;
2) get a NiMH-powered crank light. NiMH cells don't particularly like rough treatment either, but charging too much or running the battery flat every now and again is not death on a stick to them the way it is for LiIon.

Some more info in this thread I opened some time ago.

thats interesting....im hoping that the rate of charge from the solarcell is enough that you wont over charge it?

i realised i promised pictures and totally forgot...oops! ill take some now...

with 3 of the 5 other lights i have on my office table (all of which i take home everyday)

Crenshaw

Fallingwater · Jun 18, 2008

Don't really know, my knowledge of solar cells is not sufficient to answer your question.
About the solar light: it's nifty and all, but I'd be wary of putting something with a delicate glass surface in the same pocket with my keys...

Is this truely Solar Powered? (dx keychain light)

Crenshaw

Flashlight Enthusiast

Daniel_sk

Flashlight Enthusiast

Jarl

Flashlight Enthusiast

paulr

Flashaholic

Crenshaw

Flashlight Enthusiast

raiste

Newly Enlightened

Jarl

Flashlight Enthusiast

LED-holic

Flashlight Enthusiast

Crenshaw

Flashlight Enthusiast

Omega Man

Flashlight Enthusiast

swxb12

Flashlight Enthusiast

Crenshaw

Flashlight Enthusiast

Fallingwater

Flashlight Enthusiast

Crenshaw

Flashlight Enthusiast

Fallingwater

Flashlight Enthusiast

Similar threads

Latest posts