LED 4v max! can it take 6v?

Hello,

I have an LED that states 4 volt max, but I have seen some others powered by 2 3V coin cells (the 2016's I think) without resistors. Does anyone have recommendations for best powering the LED in the simplest fashion. I am currently considering testing it with the two 3V batteries (for 6v total) to see if it holds up. The other, obvious, option is to use a resistor to drag down the voltage.
I am interested in anyone that has experience in overpowering LED's with such specs and results you may have had.

I am fairly new to LEDs. Your help is very much appreciated.

Are those 2x3C coin cells wired in series or parallel? 6V would likely kill the LED.

If you're into modding, check out the Homemade and Modified section on CPF - lots of neat ideas for cool projects and very knowledgeable people.

Welcome to CPF!

With coin cells, 6V is possibly only because the cells themselves can only output a limited amount of current which isn't enough to fry the LED.

You can even power an LED with up to 12 V using those small 12V cells used for remotes etc.

Any larger cells will however, put out enough current to fry the LED if you apply more than about 4V to the LED.

Thank you for your responses.

So ... is it common to assume that the smaller coin cells are not actually putting out the voltage they specify? I have two 2016s for a total of 6v directly powering a 4v max LED, and it looks good. I loose quite a bit of brightness with the 100 ohm resistor that was originally recommended, and would rather run them brighter if possible. If the coin cells were larger, say the 2032s, would the same apply? That is, is it just the 2016s that will allow the LED to be run at 6v? How about the 2032's?

I would appreciate input from anyone with experience with the Nichia CS and data on over powering them.

Thanks in advance to anyone who responds! :thanks:

It's not a matter of the batteries not putting out the specified voltage, it's a matter of them not being able to put out the current levels (amperage) that we expect from NiMH and even alkaline cells. Both voltage and current play a factor in how bright the LED will be and on how much the LED is being overdriven.

The Nichia CS LEDs are VERY overdrivable. I have four of them (in four different lights) running direct off of either 10440 (AAA sized) LiON cells or 14500 (AA sized) LiON cells. These cells come fresh off the charger at about 4.2V and are between 3.8V for most of their runtime. The CS initially pulls about 180mA (milliamps) from the LiON cells which is about 9 times their spec'ed current of 20mA. Many lights run the CS around 60mA and they can take that treatment for a good long time.

I've killed two of the CS LEDs running them direct on LiON cells and both of those were the B0 bin which is more of a pure blue than the C0 bin which is the more typical blue in the middle surrounded by green and white.

Bottom line is, I assure you that you will have no problems with a CS LED being run on 2 2016 cells. Several factory lights run this setup... the newest Photon Freedom To The Max and the newest Inova keychain lights both use the CS on 2 2016 cells.

It is important to realize that all batteries have natural internal resistance. For those coin cells, that resistance is quite high. Chemically two of those cells put out 6V, but the internal resistance is so high that when you connect them to the LEDS, the external voltage is only 4V.

Semiman