12V LED bulbs for camping - my two cents

Alabama_Man

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Aug 1, 2020
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Hi folks!
I wasn’t sure wheter posting this here or in other forum areas, but these bulb lamps are cheap as dirt, so let’s have a look at them.
I found these bulb on a popular online store. They sell for some 2-4 bucks each, depending on their listed power. Models available were 3W, 6W, 7W and 9W, offered in both 3000 and 6000 K gradation.
I ordered one of each in the 3000 K range, and soon tested them.
To make a long story short: I think they’re awesome for camping purposes.
Now, a few details:

As far as technology goes, all lamps are COB LEDs encased in a bulb-like frame. There is no glass, and the opaque surface helps shedding smooth light. Also, being all plastic makes them less fragile and good for backpack / camping transportation.
Basically, the higher the Watts, the more LEDs are on the circuit board.

All bulbs come with a nice length of DC wire (about 1 metre / 3.50 feet), ending with useful clamps.

These bulbs require 12V, which you can easily get from any car battery or -even better- a series of 3x 18650 lithium battery cells: they are so lightweight and easy to recharge that they should never miss any backpacker’s inventory.

I have been using these bulbs for two years now in my mountain cabin, with no issues so far. Should they last a meager 1000 hours, they’re still a great bargain for the price. I even built a small 12V power supply out of salvaged 18650 cells (18 cells in 6 parallel rows of 3x series), and gets scores of hours of light before needing a solar recharge.

Last month I went camping with friends: coffee was ready, poker cards were being shuffled, but flashlights kept blinding each other. So I took a 7W bulb, 3x 18650 cells, 4x rubber bands, 2 small sticks and 2 nails to set up a jury-rigged 12V battery (see pic below). We hanged everything on a pine branch and kept playing for hours under that smooth, warm light.

Unfortunately I can’t tell anything about their actual Lumens output, but compared to 220V AC LED bulbs I have at home, these seem to yield about 90 Lumens per Watt, give or take.
9W models do not seem to overheat cells, as current should be flowing around 750 mA, a very safe amount for 18650s.

Though they are listed for 12V, they can runa s low as 8.4V, with reduced brightness output: this leads me thinking that the COB LEDs might be on the 9-24V range type.
I should try to risk killing one and overcharging it to some 16.8-21V, and see if it holds or misbehaves.
More news on this in the future.

As a side note, I tested a 3W bulb on a 3x18650 series. Cells had been harvested from a dead laptop computer battery, so they had seen lots of abuse. Nominal capacity should have been 2200 mAh, but was actually lower due to mileage.
That said, the fully charged cells ran the battery for 12 hours of full-intensity light, plus 3 more hours of dimmer light. Readings on the cells after the test revealed they still had 3V on each.

I think this is a great product for the money, its main drawback being clearly not waterproofed, though this can be easily achieved with a few minutes of toolshed tinkering.

Bulbo_12V.jpg

assemblaggio_di_fortuna.jpg
 
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CSG

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I just use Streamlight Siege AA lamps with rechargeable batteries. They are reasonably inexpensive and just work.
iu
 

Chess

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Jun 12, 2021
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not very high quality, but when I've been camping, I've been using some of the lights from Harbor Freight Tools. They hold up reasonably well, have decent light output, fairly good run time, and I dont mind much if they get a bit dinged up from camping and beating on them a little bit. When they first started selling lights, they were not something I would consider taking camping, but recently, some of their LED lights have been pretty impressive.
 

Dave_H

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I've been tinkering with 12v MR11 and MR16 LED bulbs run from 12v battery or power supply; was curious how efficient their drive circuits are, and reduced-voltage behaviour. It seems to vary with particular model. On one case I was able to run two in series with reduced brightness. As they are directional, two lamps could give better coverage.


Dave
 

Dave_H

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Though they are listed for 12V, they can run as low as 8.4V, with reduced brightness output: this leads me thinking that the COB LEDs might be on the 9-24V range type. I should try to risk killing one and overcharging it to some 16.8-21V, and see if it holds or misbehaves.
More news on this in the future.

I have a somewhat similar bulb which runs from 5vdc and has USB connector.

For 12v with white LEDs it's common to run three in series (and sometimes parallel sets) with resistor or other current limiter. White LEDs start to turn on around 2.5v each or a bit higher which explains 8v operation.

Your light might survive 16v but will run hotter, very likely shortening life. The SMT resistor in my 5v light is not very large (I managed to get the bulb off) and won't take too much heat. I would not go higher, not much to gain.


Dave
 

Dave_H

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Ottawa Ont. Canada
A great OTC source of 12v LED lighting is some automotive stores. Much of this is considered "auxiliary", "off-road" lighting not necessarily certified/suitable/advisable for main vehicle use, but perfectly good for camping, outdoor lighting e.g. solar, even indoor low-voltage. A lot of it is overpriced, but there can be good sale deals.

For example: for a few dollars I picked up a couple of #194 white LED bulbs, which I would not consider using in a car for a various reasons. Otherwise they work great, have 9 SMT LEDs with good dispersion, and very compact. Current drain at 12v is 120mA (1.44W) and still lit down at 8v.

Dave
 

snakebite

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dayton oh
i made my own from a burned out led bulb,3 nichia 219c on cheap stars,and a mr16 driver board off ebay.
i got some thermal glue from ebay too.
better quality in every way over the cheap ones.
in a larger bulb with more surface area in the funnel(heatsink) these barely get warm.
 

snakebite

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another type i make also starts with a dead led bulb.
1 nichia 219c on an al star.
a usb cable and a 2.7 ohm 2w resistor.
assemble as above.
run from your usb powerbank.
 

snakebite

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dayton oh
my guess is the one in your pic has 3s leds and a resistor.
so a bunch of groups of 3.
going 4s on the batteries will make it brighter but shorten runtime and lifespan.
you can pop the dome off and see.
this is where the cheapest way is better.
i dont like rfi from drivers.
mine dont give any detectable rfi since i wound common mode chokes in the ones i use near radio equipment.
but resistors give none to suppress.
 

JustAnOldFashionedLEDGuy

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Apr 13, 2020
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Hook it up to a meter:

- If the current goes up as the voltage increases its a resistor

- if the current stays the same it's a linear regulator

- if the current goes down it's a DC-DC

No destruction required
 
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