xoliilox
04-26-2008, 07:52 AM
Hi. This is my first post, and I can say that I feel I've learned a tremendous amount from these threads over the past few weeks. So, thank you all! A question that has come up for me is about direct driving (with no resistor). I have been experimenting with 18650 batteries (3.7v 2600mah) combined with LUX3s and K2s.
My first question is: I have a green K2 and a green 3 (both ordered from TCSS), and when I directly drive them with an 18650, the 3 is significantly brighter than the K2. This leads me to wonder what amperage these LEDs pull directly from a battery. On the lumileds website it says that a K2 typically pulls 1A and that a 3 pulls also typically pulls 1A but can minimally pull 750mA. On this (TCSS) website, the LED resistor chart says that you want a K2 at 1.5A (which I assume it's not getting?). So, a simple way of asking this question is -- if I put 3.7v into these two LEDs, and there is ample energy to power the LEDs for around/over 2 hours (2600mah), how many amps do each of these LEDs actually pull from the battery? And is there somewhere or someway that I can figure this out on my own?
Second question: I ordered a green rebel mounted on PCB. If I direct drive this with the same 18650 3.7 battery, how many Amps should I expect it will draw? I noticed on the site that I ordered from (led-tech.de) that there is a voltage typical of 3.15v and a voltage max of 3.99v, there is a mA typical of 350 and a mA max of 700, and there is a Lumen typical of 80 and a Lumen max of 145. Does this possibly answer my previous question, that there is a correlation between the amount of voltage that is put into the LED that results in the amount of Amps that it draws? If that is true, it still doesn't explain why my 3 is brighter than my K2...
Third question: I have also tried a Red 3 with the 18650 (I realize that this is a lot of voltage to throw into it) and it works and is nice and bright, is this going to destroy the LED quickly or will it be able to hang on?
I've been running these trials in a pair of Ultra stunt sabers (wraith version), just so you all know.
Thanks for the help!
My first question is: I have a green K2 and a green 3 (both ordered from TCSS), and when I directly drive them with an 18650, the 3 is significantly brighter than the K2. This leads me to wonder what amperage these LEDs pull directly from a battery. On the lumileds website it says that a K2 typically pulls 1A and that a 3 pulls also typically pulls 1A but can minimally pull 750mA. On this (TCSS) website, the LED resistor chart says that you want a K2 at 1.5A (which I assume it's not getting?). So, a simple way of asking this question is -- if I put 3.7v into these two LEDs, and there is ample energy to power the LEDs for around/over 2 hours (2600mah), how many amps do each of these LEDs actually pull from the battery? And is there somewhere or someway that I can figure this out on my own?
Second question: I ordered a green rebel mounted on PCB. If I direct drive this with the same 18650 3.7 battery, how many Amps should I expect it will draw? I noticed on the site that I ordered from (led-tech.de) that there is a voltage typical of 3.15v and a voltage max of 3.99v, there is a mA typical of 350 and a mA max of 700, and there is a Lumen typical of 80 and a Lumen max of 145. Does this possibly answer my previous question, that there is a correlation between the amount of voltage that is put into the LED that results in the amount of Amps that it draws? If that is true, it still doesn't explain why my 3 is brighter than my K2...
Third question: I have also tried a Red 3 with the 18650 (I realize that this is a lot of voltage to throw into it) and it works and is nice and bright, is this going to destroy the LED quickly or will it be able to hang on?
I've been running these trials in a pair of Ultra stunt sabers (wraith version), just so you all know.
Thanks for the help!