bought 5w led flashlight off ebay, need help

[97prelude]

i bought a 5w led flashlight off of ebay. Instruction say to feed it a single AA battery. well with a 1.5v battery its not very bright. I wired 4 AA batteries in series and it was REALLY bright, and I was wondering if its safe for me to power it with a voltage other than 1.5v. Below is the link to the same flashlight I bought.

I was thinking of putting 2 3.6V 1/2 AA batteries in the tube. Would putting 7.4V on this LED fry it? I figure its a 5W LED so it can handle it, but i don't know for sure so what advice do you guys have on increasing brightness out of this light?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&rd=1&item=360009841771

 

[Gunner12]

You were probably overdriving the LED quite a bit. Does it still work with a AA battery. The circuit might be fried from the extra voltage. The LED might actually be using 5 watts with 4 batteries.

Also, for the price, you would have been better off buying a Cree/Seoul/Rebel LED light from Dealextreme. More output for a similar price(You might even be able to find you light for a lower price, check in the generic LED lights sections).

To make it brighter? Well, the current gen LEDs have double or more the efficiency of the previous LEDs(same power, double or more output). Current gen LEDs, Cree XR-E P4-R2 bin, Seoul P4 U-bin(Good replacement for a Luxeon LED), and Luxeon Rebel 80 and Rebel 100. Previous gen LEDs, Luxeon I, III, V and K2.

So if you were able to swap out the LED for a current gen one, you would double the output right away. Might be easier to buy a new light.

:welcome:

 

[97prelude]

The light works fine, I think its a current gen LED. The reason I ask is because the same seller is selling thethe same flashlight but with a longer tube and is putting 2 AA batteries and/or 2 3.6V batteries.

 

[Gunner12]

It says Luxeon. The only two current gen Luxeon LEDs are the Rebel 80-100 and the new K2.

You light probably uses a Luxeon I or III.

2 AAs might work but 4 in series(I'm surprised it didn't destroy the driver, which power the LED) would be bypassing the driver and driving the LED at at least 4.8v, which is much higher then the 3.3-3.7v of normal drive.

Most white LEDs run at around 3-3.7v. A 1.5v battery would not power up the LED, that is why there needs to be a boost driver to raise the voltage to an acceptable level.

Next time, it might be easier(and probably cheaper and brighter output wise) to buy from Dealextreme.

 

[matrixshaman]

If it didn't fry from 4 x AA you might try getting one 14500 cell which is the same size as a AA but it is 3.6 volt and see what that does. If it does fry you haven't lost a lot but if it's really dim on one AA then it isn't worth saving probably. The fact that they say 2x AA in the ad in one place seems to indicate it's okay with 3 volt but I wouldn't do 2 x 1/2AA Li-ions at 7.2 volt or that will be begging to fry it. Like others have said here though dealextreme.com has better deals and free shipping on all kinds of inexpensive lights. And :welcome:

 

[Marduke]

My personal recommendation is to avoid buying no-name flashlights from Ebay. Also goes for flashlights with unbelievable specs for equally unbelievably low prices.