This is a placeholder topic for “LED - Assorted with Resistor 5mm (20 pack)” comments.
You don’t have to worry about adding a resistor to an LED if you get an LED with a built in resistor! This pack contains 20x 5mm LEDs in four different colors. There … read more
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How much current do these LEDs draw at 5v?
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The product photos show the LEDs being used with a 9V battery but the product listing says 3-5V.
Is 9volts ok?
Hi John,
We didn’t have any of these LEDs in stock a few days ago so I couldn’t test any on the bench, but I’ve done some testing now.
Of the 8 or so LEDs I tested at 5 volts, of varying colours, all but one drew between 16 and 22mA, one outlier drew 180mA. The colours were also quite varied, even comparing two red LEDs.
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Hi Basil,
All the documentation we can find for this product says they have an operating range of 3 to 5 volts, the product pictures we were provided that include a 9 volt battery are a mystery to us as well.
We can guarantee they will work between 3 and 5 volts, if you’d like to do some destructive testing on a couple and find their limit that is of course up to you. Operating above 5 volts will void their warranty and is potential dangerous, but a quick way to find the failure point.
Personally, I’d just use a regular LED and add my own current limiting resistor but I can see the convenience that this option gives.
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Thanks for doing that testing Trent.
I presume that 180mA outlier would have released its magic smoke 
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No, it seemed to work just fine for the few minutes I had it powered up, it was noticeable that the colour was quite different to the others in the pack, being neither red nor yellow but a reddish-orange instead.
For an LED like that with a current 10x the rest of the batch, I wouldn’t be game to push it beyond the 5V operating range.
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That was the internal fire
Cheers Bob
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Hey Bob,
In this case, it wasn’t (yet…).
Looks like QC issues with the LED, based on the current that they were able to draw at each voltage we supplied them at. They all had different resistances from what was measured (even amongst the LED of the same color) and had noticeable differences in color versus LED packs I’ve seen before. Possibly just related to the manufacturing processes used to make them so inexpensive while integrating resistors which often have a range of error themselves.
Somehow it didn’t, although it did get quite warm by comparison to the others unsurprisingly. I’d imagine that the inline resistor on it was lower than the others of the same pack for some reason, although I’m not sure why.
To answer the original question, at 5V they draw about 20mA on average (for the most part 
)
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Hi Bryce
I think that says it all and just about sums it up.
I would have to agree with Trent there.
They may be OK as some sort of stand alone indicator but if things were a bit tight I think you would be flat out calculating what sort of current needed without measurement and a bit of pot luck.
Judging on comments above if you wanted several of the same intensity you would need a bag full and trial each combination.
Would that be why they are supplied in a 20 pack???
Cheers Bob
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Or use pots to limit the voltage across each LED individually until they’re all roughly identical (highly impractical of course), although Trent is exactly right, for most LED projects just whacking on a resistor of a few hundred ohms to ensure you don’t burn it out should be easy enough.
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Hi Trent
Thanks for the response. I will stick to 5 volts. Perhaps it would be best if the photo was updated.
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Hey Basil,
I agree, I’ll get onto that today for you and fix up the site 
If there’s anything else that you’d like us to get fixed up on that page let us know and we’ll see what we can do.
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