Nuked Torch or batteries? HELP!

I've been a fool....

I recently bought a Romisen RC-G4 flashlight - with a cree q4 LED.

Like a muppet I stuck the two CR123 lithiums in upside down. There was a nasty burning smell -so I whipped them out again.

Now I've tried 2 sets of batteries - the one's I stuck in upside down, and another set that haven't been trashed.

The torch now only comes on very dim, and lasts only a few minutes.

What exactly do you think I've nuked? Could I replace the LED and driver? What do you think I've done to the batteries?

Could I stick a Q5 LED in there instead - how much quicker would drain the batteries...

AND would an 18650 last longer than 2x CR123s

Any help much appreciated

J

The driver is probably fried. Both sets of cells are most likely fine.

Thanks for replying Marduke -

The driver - is that the bit that sits between the LED and batteries?

is this something I can easily replace with a bit of soldering... any ideas were I could get one?

Thanks for your help

Marduke said:

The driver is probably fried. Both sets of cells are most likely fine.

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No probably about it. the driver circuit will die from reverse voltage like that. That burning smell was the printed circuit board and couple charred components. The LED is probably still good but can't get any power from the shorted out components of the driver board. I wouldn't try running it any more.

(so thats a +2 for your comment).

If you can figure out how to disconnect all the components and go directly to the LED with a 3.7V battery it should work and light up rather well. The batteries are drained some what but should not be "damaged".

OK, here's another question - does anyone know of a Q5 LED with a slighty more floody reflector that I could drop into a Romisen RC -G4?

I'd say for now if you've got an 18650 battery, go ahead and direct drive the light. You just carefully remove the old circuit board and strip all the electronics off, then attach the positive and negative wires to the contacts. Put it back together and you'll have a very bright light.

You can also buy a new driver and see if you can swap it in for the fried one.

As for the LED and reflector, I think a Q5 on a 16mm board should work, and the reflector, a floody optic i guess? Or maybe take the current reflector and sputter it.

Ah, now this sounds interesting.....

However the problem I've hit is that the LED is firmly stuck to the driver so I suspect I'll have to replace the whole thing.

BUT, sputtering, does this involve gently sanding the reflector to take some of the shine off?

And is a floody optic a slighty domed/concave (can't remember which) replacement for the currently flat bit of glass in the front of the Flashlight?

Sorry - bit of an amateur...

JimmerG said:

BUT, sputtering, does this involve gently sanding the reflector to take some of the shine off?

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Sputtered reflectors:

I purchased a spray can of clear acrylic from Home Depot; the kind used to put a coating on furniture. My basement is very dry, so I did the coatings there. I laid all of my reflectors on newspaper and held the can about 24 inches above the reflectors. I would spray for just 1-2 seconds to allow a fine mist to settle on the surface (too much will cause drips and ruin the reflector). I would let it dry over night, then repeat the same process two or three more times depending on how textured I wanted it. The acrylic beads up more with each successive application. For a larger reflector you might only want one or two coats. I noticed some loss of light from the texturing probably because the acrylic is clear rather than reflective.

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JimmerG said:

I've been a fool....



Could I stick a Q5 LED in there instead - how much quicker would drain the batteries...



J

Click to expand...

The Q4 and Q5 LED use the same amount of power. The reason the Q5 puts out more power is well.. Because it's a Q5 "higher efficiency" then a Q4 or any thing under it's own rating. Just like how a R2 will use the same power but put out more light then the Q5.

JimmerG said:

And is a floody optic a slighty domed/concave (can't remember which) replacement for the currently flat bit of glass in the front of the Flashlight?

Click to expand...

This Is Referred To As An Optic.

The "flat bit of glass in the front of the Flashlight" Is Referred To As A Window.

More Information Can Be Found Here

JimmerG said:

Ah, now this sounds interesting.....

However the problem I've hit is that the LED is firmly stuck to the driver so I suspect I'll have to replace the whole thing...

Click to expand...

The LED is probably not attached to the driver. It is attached to a heatsink which has a cavity on the underside for the driver to sit in. You can try to pry off the board the LED is on.

JimmerG said:

Ah, now this sounds interesting.....

However the problem I've hit is that the LED is firmly stuck to the driver so I suspect I'll have to replace the whole thing.

Click to expand...

Try applying heat.

Thanks for all this help guys - its amazing how one can can utterly swept along by a passion for flashlights.

I've ordered a few bit and pieces and should be up and running again soon.

J