this is the driver of the crelant 7g6cs ,i believe all models have similar drivers,as you can see it has 3 resistors R1,R2,R3 ,in this topic Modded: Small Sun ZY-T13 3.2 Amps or Sunwayman T40CS Clone changing the resistor you are giving more Amps to the led ,now in the crelant case ,looks like it has 3 resistors in paralel if i remove complete one what will be the results ?
i am using the flashlight with 1x 18650 and now it pulls 1,5Amps max with IMR
There was discussion of the Crelant drivers on cpfm
http://www.cpfmarketplace.com/mp/showthread.php?282356-crelant-driver-gives-only-1-5Amps
My OTF numbers for the 7g2cs was 550 lumens with an 18650 but 811 lumens with 2 16340. I assume if you change the driver to make it brighter on 18650 it might not be able to use 2x16340 anymore.
As I understand it you actually want to decrease the resistance, so you would parallel another resistor in with those. Not sure how to calculate that value though.
correct i want to make it brighter with 1 battery,i am not going to use 2x batteries.
It’s fairly straight forward, you just use the reciprocal value of each resistor when adding parallel resistors.
So on a calculator if you wanted to add 3 resistors of different (or same) values together you would use the following function.
Resistor 1 (3 ohms) + Resistor 2 (2 ohms) + Resistor 3 (5 ohms)
3 (1/x) + 2 (1/x) + 5(1/x) = 0.2(1/x) = (1/x) = 0.967
So 3 ohms + 2 ohms + 5 ohms in parallel = 0.967 ohms
Hope that made sense
Alternatively, this is very helpful to calculate them
what i dont get, is why use three resistors when they could use one 1ohm? i never quite understood why they do that.
i disconect the one “leg ” of the one of resistors and the test flashlight.
edit
now i get 0.2 less amps.
By doing that you actually Increased the resistance 
so maybe not noticeably by eye, you would have made it less bright.
you are correct ,i have to remove it complete?
no, i think you would have to add one to lower the resistance instead of raise the resistance
Exactly this
quick question… hate to derail this too much…
is it possible to replace the resistors with a smd pot/trimmer? is so what kind of wattage would it see?
edit: or is the multiple resistor configuration done to handle the current better? 3 paths for the current instead of one
Yes it is, as the sense resistors only see micro amps you would have full variable control over the output.
You’ll have to be careful though to get a low enough value pot/trimmer that you have very precise control over the resistance.
AFAIK the 10ohm trimmer pot has 10 full turns throughout the entire range so should be good.
I had this question once but unfortunately, there aren’t any SMD trimmer pots in the miliohm range. In fact, no pots do. 
The wattage doesn’t need to be great, 1/4 of a watt would do, but it does need to be pretty precise.
Edit: Sorry, there are in fact, pots that are sensitive enough to be used in place of sense resistors. 
cause i am newbie to resistors stuff with what number will be ok to change the R240 resistor for example?
im browsing through that list right now… but probably shouldnt bother until i take my zy-t13 apart and see what range i would need for it
What you’ll need is something like this
http://www.talonix.com/shop/item.aspx?itemid=3781
The problem is they’re not SMD so fitting it in there is the biggest problem.
The one I linked has 12 turns for 10 ohms so more than fine enough adjustment to control the output
Before you do anything, you should measure the current going to the LED first.
Then, adding a R250 Ohm resistor would increase the current by about 25%.
Adding resistors (piggybacking) will make the light brighter, and removing them will make it darker.
Swapping the resistors with a lower valued ones will also increase the brightness.
If you can get the exact LED current, we’ll take it from there.
from the tail its 1,4a,but to the led its dificult to do it :),thank you all for your comments i got the idea.
edit
i measure the amps to the led,its 1,32A(with all resistors)
If you look in the zy-t08 thread there is an ebay link from viffer for some 22 turn trim pots, and a video showing the current reading as adjusted.
They work as you want them too, you could then dial in your tailcap current and now you’ve measured, know your emitter current won’t be that far behind.
That’s the link to the pots, good luck with the mod.