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My gw6900 has been on "m" ever since i got it a few days ago, i dont think there's something wrong with the watch, it just havent got as much wrist time as it would like :roll:

anyway, am i wasting time (and flashlight batteries) by trying to charge it with my LED flashlight?



btw its in the box while being flashed by the led light because i dont want other light sources to ruin my tiny experiment (because science :-d )

on a side note, my solar only g5600e has been on "h" ever since i got it even if it spends most of its time inside the box. Do atomics really suck power?

thanks wus masters.
 

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My gw6900 has been on "m" ever since i got it a few days ago, i dont think there's something wrong with the watch, it just havent got as much wrist time as it would like :roll:

anyway, am i wasting time (and flashlight batteries) by trying to charge it with my LED flashlight?



btw its in the box while being flashed by the led light because i dont want other light sources to ruin my tiny experiment (because science :-d )

on a side note, my solar only g5600e has been on "h" ever since i got it even if it spends most of its time inside the box. Do atomics really suck power?

thanks wus masters.
A LED is no replacement for the sun. While it can provide some trickle charging which can come handy if your watch is really, really out of power, it generates only about a few hundred lumen of light as against the thousands of lumens that sunlight can provide, even on a mildly cloudly day! A 15-minute charge in the sun would probably charge the watch much to a better extent than 8-10 hours of LED exposure.
 

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My gw6900 has been on "m" ever since i got it a few days ago, i dont think there's something wrong with the watch, it just havent got as much wrist time as it would like :roll:

anyway, am i wasting time (and flashlight batteries) by trying to charge it with my LED flashlight?
Yes, you are. As bbsrailfan said, even a modern LED flashlight "generates only about a few hundred lumen of light as against the thousands of lumens that sunlight can provide, even on a mildly cloudly day! A 15-minute charge in the sun would probably charge the watch much to a better extent than 8-10 hours of LED exposure."

Or to paraphrase The Hitchhiker's Guide to the Galaxy: ""Even a yellow star," it would say, "is bright. Really bright. You just won't believe how vastly, hugely, mindbogglingly bright it is. I mean, you may think stadium lights for nighttime football matches are bright, but that's just peanuts to stars. Listen..." :)

Most homes that have solar panels have several of them, they're measured in square feet, and they use the SUN for power. The solar cell on most Casio watches is only about the size of a fingernail, and while it's only charging a small watch battery, it's designed to use the sun too -- the owner's manuals show how many hours of direct sunlight a watch will need to charge from "low" to "full." Those charts usually show that it takes five times longer for the same charge with sunlight through a window, and ten times as long with a window and a cloudy day. Even if an LED light was as efficient as a cloudy day, do you still want to use hundreds of hours of battery power when you could just put the watch outside for two days?


on a side note, my solar only g5600e has been on "h" ever since i got it even if it spends most of its time inside the box. Do atomics really suck power?
Your situation has everything to do with your atomic watch not being fully charged and VERY LITTLE to do with the atomic feature.

The manual for the G5600E claims that the watch should last 11 months on a full charge, without exposure to light, if it was still being used normally.

The manual for the GW-5610 claims that the watch should last 10 months under the same conditions -- so while the "receive" feature uses some power, it's certainly not using that much!
 

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Discussion Starter #4
Thanks masters. I think i got busted for the habit of not reading any of the manuals ^_^

anyway, i took it off the flashlight and will just let it hang around the dash of my car for a few days.
 

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Thanks masters. I think i got busted for the habit of not reading any of the manuals ^_^

anyway, i took it off the flashlight and will just let it hang around the dash of my car for a few days.
This time of year, in the Northern Hemisphere, you'll probably be okay -- but the manual also cautions against car dashboards on sunny days! :)


dash.png
 

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Mike is right. While G-Shocks are robust, and can put up with heat pretty well, they do have their limits and you have to be careful. Another issue is the battery. It could explode or leak... or heat up enough to release caustic fumes that damage module components. If you're in the upper half of the northern hemisphere right now, you shouldn't have anything to worry about. The danger is letting a watch bake in the hot summer sun on top of a car dashboard, especially with the windows rolled up.

Btw, I have an Eastward facing window that gets a good bit of sun up through to around 2pm, and for 3/4 of the year, on a full sunny day that window sill can get mighty hot. I've accidentally left a few watches there and found them very warm to the touch after solid exposure to the sun for an hour or two.
 
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I don't often bake my solar G-Shocks in the sun to charge them. But when I do, I like to place them in a glass of water to dissipate the heat. Stay charged my friends.b-)
 

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I've said it before, and no doubt will say it again, I find the best thing with solar watches is to just leave them out in a room to charge from ambient light.

It's all I ever do with mine, and the ones that can indicate charge all stay on HI / H.

May not be tenable if you've got many - I've got probably around 8 or 9 that are solar - and they just live on a dresser in my bedroom.
 

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I've said it before, and no doubt will say it again, I find the best thing with solar watches is to just leave them out in a room to charge from ambient light.

It's all I ever do with mine, and the ones that can indicate charge all stay on HI / H.

May not be tenable if you've got many - I've got probably around 8 or 9 that are solar - and they just live on a dresser in my bedroom.
I do basically the same thing. I have a clear-top watch box that holds my solar watches. I just put the whole box in a room that gets strong indirect light through a translucent window blind. If I do this a few times a week, all of my watches will stay on high all the time, and this way none of them ever get hot (or even warm) to the touch.
 

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If you have one that is suitable, a North-facing window sill makes a good place to charge solars. All of mine live in such a place. Often, RC's will catch a signal there as well. The really nice thing about those sills is plenty of light to keep them charged (more than enough, really) but very little direct sunlight, even in Mid-Summer.

Thanks masters. I think i got busted for the habit of not reading any of the manuals ^_^

anyway, i took it off the flashlight and will just let it hang around the dash of my car for a few days.
 

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I used to think that LEDs were not powerful enough to charge my watches. :think:

So when my Gulfmaster kept dropping to M (and all my other watches were always at H) I decided to compare my usual charging habit of charging my watches with ambient lighting through a window and a daily 2hour blast from a USB LED (roughly 3 inches away).

And yes, silly me o| forgot to turn on the power saving feature on the Gulfmaster, which was the main reason why it kept falling to M. Never realised how much juice the second hand would suck up. Curse you second hand!! :-|

I used my lux meter to check the ambient light coming through the window (no direct sunlight but still very bright) and I got between 500lux (roughly about 1.5 feet away from the window) to 8000lux (at the outside edge of the window facing outside). This was measured on a very sunny cloudless day but no direct sunlight on the window (usual scenario). The outside (direct sunlight) lux rating was 116000 lux.

So on a daily basis, all my watches are getting roughly between 800 lux to 1000 lux a day (whole day) since they all sit roughly about 1.5 feet away from the window. But obviously it was not enough since the Gulfmaster dropped to M.

The LED light that I was using on my Gulfmaster is the Xtar UL1 (which puts out 180 lumens).
xtar.jpg
I powered on the xtar and set it to medium brightness (there's Low, Medium, High/Turbo), I measured 50000lux from about 2 inches away. Even at 6 inches away I was still able to get at least 10000 lux.

According to Casio's lux chart (below) for the Gulfmaster, the LEDs were equivalent to outdoor sunlight and sunlight through the window.
gwn1000-charge-table.jpg

I blasted my Gulfmaster with the LED from around 3 inches away for 2hours a day. It went to H after only two sessions. And (with power saving on), it has remained on H ever since.

So, the ambient light that I get through the window is surprisingly not enough to keep the Gulfmaster on H if power saving is not used (again, curse you power sucking second hand!! :-| ).


So, are LEDs efficient? Yes, power-wise, based on the setup I was using. Of course, the LED quality would also determine how much juice you can get out of it. High powered Cree-based LEDs are good.

But, it is certainly not cost efficient. LEDs will burn out in time. Plus, if running on batteries or rechargeables, it will become very costly.

And there's just no comparison with taking the watch out to wear in broad daylight (you will get > 50000 lux easily, and a suntan, plus it's free).

However, as a quick jump start, the LEDs work fine in jacking up the power levels. I was so paranoid in seeing the M in the Gulfmaster that I just had to do something about (and it got no air-time since my go to watch is the Ambit3).

Sorry for the lengthy post! Just thought I'd like to share my experience. :)
 

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My gw6900 has been on "m" ever since i got it a few days ago, i dont think there's something wrong with the watch, it just havent got as much wrist time as it would like :roll:

anyway, am i wasting time (and flashlight batteries) by trying to charge it with my LED flashlight?

btw its in the box while being flashed by the led light because i dont want other light sources to ruin my tiny experiment (because science :-d )

on a side note, my solar only g5600e has been on "h" ever since i got it even if it spends most of its time inside the box. Do atomics really suck power?

thanks wus masters.
To answer your question, first you need to understand the difference between Luminous Flux, Luminous Intensity, Luminance and Illuminance. This video will help.

Then you need to understand how Photovoltaic Cell, Semiconductors, Silicon Fabrication, and P-N Junctions work. The video below will help.

Hopefully, after the study you can answer your own question. ;-)


Theoretically, it IS possible now to have the equivalent luminance of natural sunlight by using an extremely powerful LED lamp (see example below), pointing at the right angle (90 degrees), at a very short distance, and to the small area of your watch crystal. But doing so, you are basically wasting energy from another artificial energy source, especially when the small and lower grade solar panel on your watch is not that efficient (no more than 1 Sun or 1kW/m^2).

32,000 Lumen

100,000 Lumen. LOL, this is just crazy! ;-)
 

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Yes, LED will charge. I got a dead GW6900 to full level indicated under a LED lamp in 24 hours. It just takes a really long time at medium (full day).
Put the watch under the bulb, not on top to keep it cool. The closer to the bulb (not touching or close enough to get hot!) the faster it will charge. My watch was a few inches below the bulb as in the picture.
 

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Hello!! DO NOT LEAVE A G-SHOCK ON THE DASHBOARD OF A CAR! It may melt the plastic parts inside and out.

Very bad idea.

Instead, Wear it uncovered on your wrist with your sleeve rolled up and it will be charged. Afterall IT IS A WRISTWATCH!!
 

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Yes, LED will charge. I got a dead GW6900 to full level indicated under a LED lamp in 24 hours. It just takes a really long time at medium (full day).
Put the watch under the bulb, not on top to keep it cool. The closer to the bulb, the faster it will charge.
The closer to the bulb, the higher the chance of damaging the watch: http://forums.watchuseek.com/f17/omg-i-just-fried-my-gxw-56-kings-display-went-negative-now-become-positive-584823.html

There are other threads around here that end with the same sad result but I get tired of looking for them every time this topic comes up again...and again...and again.

Pretty much everybody on the planet who owns a solar-powered watch has access to sunlight, even in the winter, and it's free.
 

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Considering the amount of torches I have to cook them solar G's, I have no issue in making then from Medium power to HIGH power within a day of continuous power from LED Torches. Yes, they are using electricity and may not be practical for some. But with the Sun's uv rays, heat and all the atmospheric elements combine, I didn't want to risk the trouble of killing the G's. The LED's are much cooler to shine them through 🏼

I use maximum output only for Low power G's and when they come to Medium, I set the torch power to about 50% which normally last for a good solid 12hrs+ And yes, they do come High power eventually. If you got power to burn and the amount of batteries i got, no problem at all in reaching HIGH

Burn LED burn...

-Kawei-


Sent from Kawei HQ...
 
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