question about direct drive ْfrom 18650 cell

Flashlight Modding and DIY Parts
1

Hi all

After i knew that i can direct Drive a XM-L2 directly from a 18650 cell i tried it

and here is some results

setup was XM-L2 t6 3B on Noctigon fixed on a big copper heatsink , 2.6A Red Sanyo R1122 cell pulled from a laptop battery

I got about 4.5 A only while some members got about 6A from from direct driving

I made another test i tried the same setup but with 2x XM-L2 in parallel i got about 5.8 while the cell were at 4.1 volts

My question is why i cant have those 5.8A with one XM-L2 ?

and in generally as i can direct drive XM-L2 from 18650 cell, Can i direct drive a 3x XM-L2 in series with 3x 18650 cells in series ( 12.6 volt ) or its dangerous for the leds ? ?

2

The direct drive current is limited by the LED vf and battery voltage sag under load. You will be able to get higher current with a better cell that doesn’t sag as much under load.

Edit: With two LEDs in parallel the vf is lower because the current through each LED is lower.

3

tried parrallel on those 18650s?

4

A meter is a really good way to get an inaccurate current measurement.

Yes. 3 + 3 + 3 is the same as 3 x 3, isn't it?

5

i will try it today

6

ok thank you i will try it today

and about the ( A meter is a really good way to get an inaccurate current measurement. ) what i can use to test ?

7

Either a modded DMM or a clamp on meter. I sell external shunt resistor modded DMM’s that are accurately able to measure DC amps up to and above 20A, if your interested check my thread in the want to sell subforum.