Cheap Flashlight Mod

Found this cheap ($2.50) single AA flashlight and saw it had a legit Cree XP-C LED in it. It has a decent brightness and useable for EDC use. But I hated its bluish white tint (possibly the cheapest Cree LED bin they could get).

It is absolutely tiny. About the same size as my index finger.

Business end. It has a plastic lens and smooth plastic reflector.

Original LED is ok, but slightly bluish. I did not like it so much so I wanted to play with it.

Took apart the pill in preparation of the mod.

Driver board is a 3 mode (high, low, strobe). Battery draw at 1.5V is 1.67A high, 0.45A low, 0.8A strobe.

Current stays regulated between 1.45V up to the LED Vf. It tapers down when battery voltage falls below 1.45V but still keeps operating to below 0.5V (my bench supply minimum output) but circuit will not restart below 0.9V.

Here is the LED I ordered. It is said to be a Samsung chip at 4000K but appears to be warmer than that. This is the listing I got it from.

A bit of research and these appear to be Samsung LH351B devices.

Reflowed it using a hot air tool on the back side of the metal core PCB.

Mod completed. It is a warm white LED not neutral white as said in the ad. Still useable though, being underpowered, it should be brighter and more efficient.

Compared it to another with the original LED in it. This is on a white sheet of paper.

Beam spot is smoother but a little more floody due to the bigger die. Brightness appears to be the same.

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