DIY flashlights costs 20 cents each 1 watt, and grow LED's for seedlings that cost 80 cents!

[Matt Gruber]

of course there is a catch :lol: i'm using old 18650's from my well used Makita packs from my -9 scooter.
2 cells were not holding the voltage, so i switched packs. might as well use them since they are from 2011 and have a limited life remaining.
so i ordered 10, 3 watt led's for $1.12 https://www.ebay.com/itm/NEW-10PCS-LOT-3W-High-power-LED-CHIP-beads-lamp-white-blue-red-green-yellow/263053999669?hash=item3d3f3d7e35:m:m0gKc5Dh1DgPK027qr08sKw and for faster delivery 10, 1 watt for 1.95.
So i'm bored, and i'm going to make a few with the good cells. I'm just going to hot glue 1 led and a switch i have laying around. With a resistor. No case :lol: so you can't get any easier than that 8)
I'm sure you have made DIY lights, so post pics if you like :thumb:

 

[markz]

The only question is
- How many Lumens?

I see lots of "Chinese" ads for 15,000 Lumen flashlights, the same kind of ads for 8Ah 18650 cans, where the most you can get now is 3Ah or 3250mAh maybe 3500mAh <---MAYBE

 

[Matt Gruber]

i go by current to judge. ad says 350ma for 1w and 700ma for 3w.
very hard to put a lot of current into a led without it burning up
that said, it would not surprise me if the 1w is brighter than the 3w

 

[Matt Gruber]

so i figure i need 1.7 ohms to drop 4.2v to 3.6v at .35a. i'm using a dual switch (surplus Nintendo).
off/on and momentary on for turbo boost (when cell drops below 3.8v)
i have some skinny modem wire, about .5 ohm per foot. plan is to wrap about 3' around the cell, and center tap it for turbo boost 8) hot glue the wire and switch and see if it heats up enough to melt the glue
this cheap resistor keeps the cost as advertised :lol:
years ago i bought a box of the high quality dual switches for .17 ea pair, ( no longer available).

 

[Drunkskunk]

Sounds like a cool idea. But that style of LED can't run without a heatsink. Got a plan?

 

[Matt Gruber]

Sounds like a cool idea. But that style of LED can't run without a heatsink. Got a plan?

Plan is to JB Weld it to the neg end of the 18650. thanks for the heads up 8)

 

[The fingers]

I bought a Chinese cheapo flashlight at Harbor Freight which barely out lasted the cheapie batteries it came with. :x

 

[Matt Gruber]

the 1w cool white testsusing 10a diodes instead of resistor)
cell v. 4.11 w/1 diode led gets 3.29v .36a
..............w/2 doides in series 2.71v .04a
DIRECT 1 amp just for 2 sec. got hot.
.
cell 3.86v w/1= 3.07v .23a
w/2 diodes .01 amp
epoxied 1 to the -end of cell which still has spot weld tab 8) . 2nd one even got flux for easy soldering. not much room to work :lol:
not much excess heat to dissipate, but they need to be mounted anyway. jb weld ready tomorrow 8)
.
3w plain white not due until next month

 

[Matt Gruber]

i like the WIDE angle better than my other flashlights. covers half the room no need to point it, it just goes everywhere
and cool white is, well, 8)
went with 2 on/off switches- full pwr and LOW which is like a full moon X2 and is only 10-40 ma, 1 chg could last 24hrs vs 3-4 for full pwr. Low is great when i don't want to wake up :lol:
no over heat, epoxied to the cell, before it got warm pretty quick on full. after 5 min on high, the warmest spot is 107F
.
the 3w, when they get here, may go in the tail lights on my 61 (keeping the 1157 too)

 

[Matt Gruber]

my favorite is a converted harbor freight "head lamp". With a light strapped to my forehead it is impossible to not have enough light, and both hands are free.
ebay has 18650 models, as little a $6. Buy one if you don't have a head lamp 8)

 

[Matt Gruber]

converted an old reading desk lamp to the led. 8) Here is an ebay pic of the exact model i have https://www.ebay.com/itm/BLACK-LAMP-DESK-OFFICE-READING-DORM-TABLE-105-013105-028-FLEXIBLE-GOOSENECK/363024316193?hash=item5485ef7721:g:gwQAAOSwMNhe6k1T
cut off the cord, and put a cell in the base. added the Hi/Lo switch w/ 2 diodes as resistors :thumb:
i like this much better, as i can quickly move it to any location, without needing to plug it in 8)
the led is epoxied to the shield. will see if it takes the heat, in actual use.

 

[markz]

Great for working on a Tesla in the garage.

converted an old reading desk lamp to the led. 8) Here is an ebay pic of the exact model i have https://www.ebay.com/itm/BLACK-LAMP-DESK-OFFICE-READING-DORM-TABLE-105-013105-028-FLEXIBLE-GOOSENECK/363024316193?hash=item5485ef7721:g:gwQAAOSwMNhe6k1T
cut off the cord, and put a cell in the base. added the Hi/Lo switch w/ 2 diodes as resistors :thumb:
i like this much better, as i can quickly move it to any location, without needing to plug it in 8)
the led is epoxied to the shield. will see if it takes the heat, in actual use.

 

[Matt Gruber]

got the 10 3w leds, $1.12 and made an overhead light strip 9 feet long has 9 leds 400 ma, w/switch for 8 which boosts it to 600 ma.(rated 700ma max)
old parts recycled- 24v scooter charger- old transformer type
9' 1x3 baseboard, from trash day
very strange light - i'm sure visitors will comment on it. it reminds me of the lights you see in a used car lot. each led is very bright, hard to look at directly. my 31 year old 4' flourescent is failing- comes on when it feels like it so now i have something different 8)

 

[Matt Gruber]

i converted an old closet light to 1w led and 18650. i put it in the bathroom so, in the middle of the night, when there is no moon, i can click it on, without using the bright light. 2 diodes in series to keep it dim.
looks like this one https://www.ebay.com/itm/AmerTac-Cabinet-Closet-Touch-Light-White-Round-Wireless-Battery-Operated/283911222837?hash=item421a6d7635:g:QbIAAOSwObhaT529
as you can see, i'm running out of ideas :lol:

 

[Matt Gruber]

ordered another 10 leds for 1.95. this time 4-4.5k for growing seedlings. While the temp here in FL in winter is near perfect, like today 75F, it can be windy or cloudy or raining, and not much sun due to the short winter days. I put seeds in back of my house to avoid the wind gusts to 30mph, but half shade With these grow leds i can start seeds in the spare bathroom, or just stick the lights outside as needed.
I've never seen grow lights like the one i'm making, but i didn't look at many. usually they are expensive. who wants to grow $2 worth of greens for $5 in electric My design uses 4 leds per 22" aluminum pipe, so 80 cents to buy, and only 4 watts, or 2 days of fake sun for a penny. 8) i made 4 spring clamps out of 12 awg solid copper wire. so they slide on the pipe(from old chair) allowing adjustment of the spacing from 2" to 6" and they can rotate if a plant comes up off center. the pipe has a hole in each end for a pin to stick it in the ground. pins are from a coat hanger. so the entire 4 led grow lamp really does cost me 80 cents. Power is from a 12v switching ps from my old modem.

ebay leds even cheaper! 1.29 for 10
99.5 rating 8) https://www.ebay.com/itm/1W-3W-5W-10W-50W-100W-High-power-SMD-Chip-LED-COB-White-Blue-Red-Light-Beads/124011607823?_trkparms=aid%3D1110012%26algo%3DSPLICE.SOIPOST%26ao%3D1%26asc%3D229666%26meid%3Dea4e7d9c84cd400894bee8e5eb1b1fd8%26pid%3D100008%26rk%3D1%26rkt%3D12%26mehot%3Dpp%26sd%3D122044236962%26itm%3D124011607823%26pmt%3D1%26noa%3D0%26pg%3D2047675%26algv%3DPromotedSellersOtherItemsV2%26brand%3DCh&_trksid=p2047675.c100008.m2219

edit: while the 1st fixture took an hour to make, #2 took 1/4hr. not including mounting and wiring as the led's are not here yet.