Everlasting Solar Camping Night Lite

http://www.ledlights.greenwatts.info/ This simple project converts two solar garden lites and some PVC thin walled central vacume pipe into a pocket sized LED solar powered lamp that can be used as a night/comfort light or reading lamp. The finished lamp is water proof, will float and will last virtually forever and cost under $10 to make.

The circuit uses two NiCd AA batteries in series which under-drives the LED array giving off enough lite to be usable but consuming very little power. The batteries will last for thousands of recharges, the LEDs are rated for over 100,000 hours and the solar cells last over 20 years.

Step 1: Materials and Components

Disasemble the solar garden lites we are going to use the solar cells, the NiCd AA baterries and one of the Schottky diodes that you will find on the little circuit board. The solar cells may be glued into place but you should be able to carefuly free them. We will also need some wire, a small resistor and 12" of central vacume pipe. For tools you will need a utility knife, 20watt soldering iron, and small screw driver. You will also need clear silicone, PVC cement and super glue. http://www.ledlights.greenwatts.info/

Comments

[Schmidty16]

also could u use a lighter to melt it on like some tin to heat it up

[Schmidty16]

love iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiit cant wait to make one its awsomeeeeeeeeeeeeeeeeeeeeeee plzzzzzzzzzz contact meeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee

[helpmonkey]

more details are now on http://ledlights.greenwatts.info

[draghi]

All the links are still pointing to the down website an the last one hasn't changed. great instructable. only just read it not built yet so adding to list.

[-max-]

WOW now that's a LOT of steps.!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[andybuda]

hi very good instructable top mark
never thought to use pvc pipe like this even though you can make beer mats out of yogurt pots in the same way and plant pots out of old vinyl
im going to have a go at making something like this but to power some leds on a photo switch and charge batteries by solar iv not had much look with the led though cant get the right power to them they work fine with 2 aa batteries but wont seem to work in parallel(just 1 lights up)

[mr. clean]

this is a great instrutable i love my light and something you can do instead of cutting squares out for the solar pannels is drill holes for the leads to run through and silicone the pannels right to the top of the box. one thing i can't figure out though is why there are allways 2 or 3 LEDs that dont light up can anyone help.

[helpmonkey]

...also do you have any pics of your lamp would love to see them?

[mr. clean]

heres some pics, and the all the LEDs light up but some not as bright or very dim as u can see in the pic. if i do need a higer forward voltage how do i achieve that? In the third picture of the switch i used a mini toggle from allelectronics.com and over the switch is a piece of plastic tubing fitted over the switch and siliconed, the other end is simply melted shut.

[helpmonkey]

Hey great pics and good job mr clean! the only solution is to replace the LEDs that dont light up as increasing the voltage can only be done by adding more batteries which complicates the solar panel etc... At my local dollar store they have 24 LED night lite fro$2 ... pretty cheap ... also I am working on a new light that will use a joule thief circuit ... the advantage is the LEDs can be over driven without damaging them with heat ... I will be posting plans on my website greenwatts.info

Wayne

[mr. clean]

i noticed a small problem when ever i try to go to greencamplite.info it comes up with a completely different page, just thought id point that out. and as for the new light ur building i can't wait to see it! :)

[helpmonkey]

you either have a couple of bad leds or possibly some leds that require a higher forward voltage to turn on ...

[VadimS]

NiMH batteries last about 50% longer and contane more energy but NiCds have a slightly higher efficiency, so NiMH would take longer to charge but the light would stay bright longer and the battery would last about 3 years (apposed to 2)

[ReCreate]

Why are the images soo tiny? it hurts my eyes looking at them...

[mattccc]

how long dous this last

[helpmonkey]

a long long time... it under drives the LEDs which increases thier life span ... which in turn is easy on the NiCd batteries increasing their life span and the solar cells will last 20 years or more

[CybergothiChe]

That's cool, G!

[mchenson]

I like the idea of using the piping for a container! But I have a few comments. Connecting the positive of solar cell to the negative of the other is called SERIES. Parallel is when you have positve to positive & neg to neg. The output of the solar cells are 4v in bright sunlight, so an expensive Schottky diode is not called for. Any low power silicon diode would do. The difference is less than 1/2 a volt. You should draw a simple wiring chart so people know exactly where things go. Finally, the output of the Nicads are only 2.4 volts, which would make the LEDs, especially white ones very feeble. Find a way to get 3 nicads working and you will really go to town!

[thecheese429]

"The output of the solar cells are 4v in bright sunlight" "Find a way to get 3 nicads working and you will really go to town!" Maybe having three solar panels, and 3 nicads, and the LEDs wired the same way. Great instructable, I hope to build one of these (Eventually...........)

[helpmonkey]

thanks mchenson ... the parallel was a typo (ill fix it) ... the schottky diode came out of the solar garden lite so really didnt cost anything ... the wiring diagram is on www.greencamplite.info ... as for the batteries we want to underdrive the LEDs which gives us the very low power usage ... even at 1mA there is quite a bit of usable light for its intended purpose ... I will be designing a high power unit using emitters and 6 NiCds with fold out solar cells :o)

[FeedTheGrid]

Nice construction. I'd like to make one of these. Thanks.

[helpmonkey]

I have been using the light as a night light in my 5 year olds bedroom ... I let him operate it as it is completly safe ... and amazingly he is going to bed with much less fuss :o)

[Grumpy_Fish]

I'm definitely playing with PVC this weekend, but out of curiosity, wouldn't the switch present a possible failure point (especially by way of moisture infiltration)?

[helpmonkey]

Its a push on push off and I placed a light coating of clear silicone around it so it should be good ... i could not locate a water proof switch :o( ...

[baken411]

i never thought about melting a pvc pipe to get flat plastic, great instructable 5 stars

[RiddleOfSphinx]

Yeah, I was wondering about how to go about doing that one day. Thanks for the tip. This would make a very good survival pack addition, too :)

[helpmonkey]

yes the thin walled PVC is very nice to work with just make sure you dont overheat it ... you can also do the same thing with ABS palstic ... it is a little harder to work with but much stronger

[hominid]

Inspiring. I couldn't find the value of the small resistors. Do you mention that? Thanks Kind regards Hominid.

[sw]

Since the LEDs are being driven at 1/10 of their power, and there is no chance of the Nicads putting out more energy, the resistors are not needed. All they do is WASTE electricity.

[helpmonkey]

yes I fully agree but I always use resistors with LEDs besides with this circuit they dont waste much

[helpmonkey]

I used four 10 ohm 1/4 watt resistors in parallel which gives you 2.5 ohms...