Renewable Energy Questions/Discussion > Renewable Energy Q&A

Using High Power LEDs to Make Lights

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WooferHound:
I had found a few videos on YouTube about using High Power LEDs to make all kinds of lights. So I went on eBay and found this listing for LEDs from 1 to 100 watts.

https://www.ebay.com/itm/High-Power-1W-3W-5W-10W-20W-30W-50W-100W-White-SMD-LED-COB-Chip-Lights-Beads/122044236962?hash=item1c6a6744a2:m:mrwPJXkCqGpBSWx5zzsnzvA&var=421059306307

The prices were amazing, Shipping is free, and the seller was in California instead of China. Purchased a Lot of these and it only came out to $25 total. Be sure to click through to his Store and look at all of his LED products.

LEDs are powered at a certain Current, so a current limiter is needed to to use them. I found these Buck Converter Voltage Regulator/Current Limiters on eBay for $2 each, so I got 10 of them to play with. Perfect for powering LEDs from my 12 volt Solar Power system. They are rated at 5 amps but aren't stable above about 3 amps. The Output is a bit noisy so some additional filtering is helpful but not necessary.

https://www.ebay.com/itm/5pcs-XL4005-5A-DC-Buck-Step-Down-Voltage-Converter-Constant-Current-Power-Module/142632518904?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649



Small LEDs on the left are 1-3-5 watts. They look identical and I need to keep them in their packets until they are needed or they will get mixed up. The LED on the big heatsink top-right is a 10 watt. The Large LED bottom-right is a 20 watt. Buck Converter at the bottom.

I've been playing around with this stuff for about 3 weeks now and I'm very impressed.

First thing is, they get very hot. Assume that all the power that you put into them will come out as heat, a heatsink is required for anything over a minute. I have been gluing them down to heatsinks using 5-Minute Epoxy with very good results, the LED must be pressed down firmly to squeeze out the glue and get good thermal contact with the heatsink. I have had much better results using CPU Coolers, small heatsinks with a 12 volt fan attached. The fan gets the 12 volt directly while the LEDs are powered through the Current Regulator. Using a resister inline with the fan will slow it down and make it quieter. A small heatsink is fine for the 1 and 3 watt LEDs but a fan is needed for ratings 5 watts or more because the heatsink would need to be so too big.

The LEDs come in 4 versions of White . . .
Warm 3000-3500
Natural 4000-4500
White 6000-6500
Cool 10000-15000
I've tried the Warm and the Natural versions. The "warm" is a little green but nice and warm. The "Natural" is very nice and realistic. An order with some "Cool" versions will arrive in the middle of next week.

The LED Specs are . . .
1w - 3.5v - 350ma - 105 lumins
3w - 3.5v - 700ma - 270 lumins
5w - 6.5v - 700ma - 550 lumins
10w - 10v - 1000ma - 950 lumins
20w - 31v - 700ma - 1700 lumins
30w - 31v - 1000ma - 2750 lumins
50w - 31v - 1700ma - 4750 lumins
100w - 31v - 3500ma - 8500 lumins
They spread light 180 degrees from the face, but they are brighter with better color in the center area, They are rated at a 120 degree angle. The Higher power versions are harder to work with because of the 31 volts need to bring it up to Full Power. About the only way to use them is with a Boost Converter so I have decided not to mess with anything higher than 10 watts that requires 31 volts. It is easier to use multiple 5 or 10 watt LEDs to make the lighting and it's better light because it is spread out more.

The light coming from these things is a point source and it can hard on the eyes, If you look directly at them for more than just a glance, then you will see dots for hours burned into your eyes. Some kind of fixture needs to be used that will spread and soften the light and make it more appealing.

After playing with this batch of LEDs I put in another order for the ones that I liked, plus a few colors including Ultraviolet. Should be here in a few days . . . Can't Wait . . .

hiker1:
Are you thinking of a bike lite with those...?   Thought about rewiring this...super brite..

WooferHound:
Here are some more experiments that I made to learn more about these LEDs



The first thing I made is pictured on the Left. I glued two 1w LEDs to a strip of aluminum. One was a Warm White and the other was a Natural White. This was to see what the colors look like and to see how much heat they produce. Powered from a 4 volt Lithium Ion 18650 battery with 2 ohm resisters inline. This got almost too hot too touch and is when I realized that I need some real heatsinks to use these lights.

The item in the center is an emergency light I made with a single LED with a good heatsink. It does not have a switch and powers up when a battery is inserted. It will run for about 5 hours on a 4 volt 18650 battery. I tried this one outside at night to see if this 1w LED would be useful on the Bicycle and was pleasantly surprised at how well it works, it lights up the whole area. The 1w LEDs are 3.5v at 350ma so I would only want to use 1 with the single battery on the bike.

The light on the right-hand side was built yesterday. It's built on top of a 2100mah Lithium Cell Phone battery. It has a single 1w Warm White led glued to a small heatsink, then glued to a big nail. Everything is glued together with 5-minute Epoxy. It has a Slide Switch and a 1/8 inch plug to be used for charging the Cell Battery. Best for emergency lighting but it was more of a fun little project



The most useful thing I made was this cute little battery powered Gooseneck Lamp. It has Two 18650 batteries for 8 volt power, and it uses a 3w LED which is 3.5v 700ma. Inside the chassis box is a Buck Converter to regulate the power to the LED so it stays the same brightness and color as the batteries drain. It will last over 6 hours on charged batteries and the 3w LED makes it wonderfully bright. Really nice to use when working close to some small projects and need good lighting.



Should get my new LED order in the mail tomorrow. I have already started assembling a couple of things that I will use those LEDs for.

Pete:
Looks like you are having lots of fun Woofer.
I like the cute little light on the aluminium box.
We use 12 volt lights in our house, a mix of LED bulbs and LED dichroic lamps.
The new 12 volt LED bulbs are great, I find a 7 watt LED bulb is great as a reading lamp, general lighting.
Keep on experimenting,
Pete

Wolvenar:
I remember buying LED lights ~1 watt  in the early 2ks
At one time I checked they were $40+ I finally got one for a flashlight once they dropped to about $25

That flashlight works flawless to this day. It's been through 3, 6v lead acid batts in its life, but the led is still going strong.

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