k2 led and ampers

karlosk98

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Hi everyone,

I´m new into mods, planning to make a k2 led light, my question is if it is rated at 130 lumens at 1.5 mA, how can it stand 6000 mAh from a C Cell, is it because one stands for seconds and the other for hours?
I´m planing to use 3 Nimh AA cells at 2.5 mAh, will it burn it or do I have to use instead 1.2 mAh AA?
I will apreciate your answers. Thank you.
 

TigerhawkT3

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Okay, here we go:

1.5A (amps), not mA. That would be 1500mA.

mAh is the capacity of a cell. It has nothing to do with how much current it can handle. mAh is mA*hours, so a 1000mAh (1Ah) cell could do 1A for an hour, 0.5A for 2 hours, 100mA for 10 hours, etc. Remember, though, that different types of cells can all handle different amounts of current. For example, an alkaline wouldn't be able to handle 1.5A, while a NiMH or Li-Ion could do it easily. 3 2.5Ah NiMHs should be fine for your light. Just remember to use the appropriate driver or resistor.
 

rolling

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Use an Seoul P4. Its brighter ,more efficient and have the same package than a Luxeon III and almost the same as a k2 except it is round.
 

yellow

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K2 or Seoul or Cree might stand direct drive form 3 AAs, but its not recommended.
K2 sucks, its just good for heating something up, get another Led

Any led where the specs say "1.5 A" (or "1 A" by now for Cree or SSC) will not survive, if You are pushing 4 times!!! the max recommended current through.

Take care in heatsinking. Just from reading the post, I would suppose: "make the heatsink 4 times larger", even if You end up using a current of 1 A "only"
;)

I d' recommend this setup: the 3 batts, one resistor of at least 0.7 Ohms, led,
no matter which size of batts You use
 
Last edited:

karlosk98

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TigerhawkT3 said:
Okay, here we go:

1.5A (amps), not mA. That would be 1500mA.

mAh is the capacity of a cell. It has nothing to do with how much current it can handle. mAh is mA*hours, so a 1000mAh (1Ah) cell could do 1A for an hour, 0.5A for 2 hours, 100mA for 10 hours, etc. Remember, though, that different types of cells can all handle different amounts of current. For example, an alkaline wouldn't be able to handle 1.5A, while a NiMH or Li-Ion could do it easily. 3 2.5Ah NiMHs should be fine for your light. Just remember to use the appropriate driver or resistor.

Supose you don´t use a resistor just a heatsink, can a k2 handle 3 AA cells at 1.2 volts and 2.5 mAh or would be better the same just at 1.2 mAh?
Thanks.
 

Mockingbird

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For your purpose using the 2.5 mAh battery or the 1.2 mAh battery will give the same result, except the 2.5 battery will give longer run time. However, do NOT use either type of battery hot off a charger. The voltage is too high hot off a charger.
 

mdocod

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The current that flows through an LED is not determined by the MAH capacity of the batteries you are using. It is determined by the input voltage to the LED.
 

kanarie

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The current that flows through an LED is not determined by the MAH capacity of the batteries you are using. It is determined by the input voltage to the LED.
So in case of 3xAA 1,2v (total 3,6v) and a Cree. Will Cree will suck about 900- 1000 Mah ??
 

karlosk98

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Mockingbird said:
For your purpose using the 2.5 mAh battery or the 1.2 mAh battery will give the same result, except the 2.5 battery will give longer run time. However, do NOT use either type of battery hot off a charger. The voltage is too high hot off a charger.

Yes, but do you need a resistor? How long do you have to wait? Thanks
 

DUQ

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You should be able to direct drive a K2 with those cells. You need to look for this (below) when you choose a K2 to buy. The Vf is listed as the last letter in the bin code --> UYAN N being a vf of 4.23v - 4.47v

K............3.51V - 3.75V
L.............3.75V - 3.99V
M............3.99V - 4.23V
N............4.23V - 4.47V
 
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