500 Lumen drop-in for SF 6P

[cpfmember]

Hi everybody

Just wanted to share my latest mod I finished:
It's a SF 6P drop in with 4 Rebel 100 LEDs and 4 rebel reflectors (from Wayne). I call it RebP500.
The rebels are direct driven from a 18650 Li-Ion battery and take about 500mah each.
All in all you get roughly 500 LED-Lumens for 1 hour. Not bad for your old SF 6P. Up to now I did no runtime test, so I can't say anything about the heat issue. But I guess for my short time operation up to 10 minutes it should work. And as I use it with a two stage switch it is very versatile.
The beam pattern is (as the reflectors themself) comparable to the SF L4, just way brighter = a true wall of light. I would say to my eyes the hotspot is as bright as the one from my preferred SF L5, just about 4 times larger. The picture of the beamshot does mislead a bit.
Just wanted to share this idea with other modders and encourage them, even if its small: it works. My next idea is a 7 Rebel drop-in for a SF U2 clone.

Dominic

RebP500 on the left SF L5 on the right

Base is a drop-in from DX

 

[021411]

Will this mod ever be for sale?

 

[nuggett]

Very nice!

 

[tino_ale]

very cool!
looks like your LEDs are wired in parallel... Did you Vf match them?

 

[cpfmember]

Sorry to disappoint you but the RebP500 won't be for sale. At least not from me. Besides that I don't have the time to produce them, the unit would be quite expensive as the parts themselves are about 100$.

But perhaps another modder is interested and able to produce and sell them.

Yesterday I compared the RebP500 with my 10watt HID (flood one) and its quite comparable. The LEDs are a bit more focused.

 

[depusm12]

Is it more flood than throw?

 

[cpfmember]

Yes its more flood than throw.
You can't expect much shrow from such small reflectors, even if you take 4 of them.

But I like the beam as you have a great mix between sidespill and a bright, large hotspot.

Great for indoor and up to about 15m.

 

[PhotonAddict]

Nice mod! How did you mount the LEDs? Were they epoxied to the heatsink or did you use one of the PCBs from the Shoppe?

 

[cpfmember]

I already bought the Rebel100 mounted on a pcb (german seller) so I had just to fit these pcbs to the space I have.

 

[Mash]

WHat did you use as your base? Ie the bottom aluminum bit of the pill.

 

[Raoul_Duke]

Very very cool!!!!

 

[weed099]

Oooohhhh I want one!!!!!!!!!!!!!!!!!!!! Wish I had the skill to do that. Who wants to build me one?

 

[cpfmember]

The bottom (where the Rebel-PCBs are mounted) is an ordinary 2mm thick and 20mm in diameter steel part form a DIY-shop.

Btw: has anybody a good idea for a driver that I could install?

I had to find out that the current drawn drops within the first 30 minutes of use to 1500mah. So a small step-up converter to 2000mah or 2500mah would be nice. I have the same space available as in the normal DX-drop-ins.

 

[Mash]

For the driver, try a 1.2 or 1.4A one, and with LEDs in parallel you should get 400 to 500mA each. I also would have said the 4-18V kai one, but i dont think you would have enough Vin to run three LEDs.

As for my question regarding the "bottom bit", i meant the bottom of the pill, ie the tapered sectin which connects to the battery + point. Is it from a DX diy drop in set?

 

[cpfmember]

Yes the bottem part is a down-cutted DX DIY-drop in.

I just found out that a Shark circuit should do the job (I just have to solder the Rebels from prallel to serial). But then I should get up to 700mah per LED.
And this would then be close to 700 Lumens. Not bad.

 

[mdocod]

I'm dazzled by this mod, pure genius!

 

[nein166]

Yes the bottem part is a down-cutted DX DIY-drop in.

I just found out that a Shark circuit should do the job (I just have to solder the Rebels from prallel to serial). But then I should get up to 700mah per LED.
And this would then be close to 700 Lumens. Not bad.

The shark can do the job but not off a 18650, 2xCR123s could work.
Wayne has a formula for minimum Vin on this thread
You'll be boosting up to 12-14v for 4 series Rebels and the amp pull on a 18650 would be about 3.5-4A.
Try it with a protected 18650 and you may get a flash of light out of it.
It could work at a lower level like 500ma as the shark is dimmable

 

[cpfmember]

Doesn't state Wayne exactly in this post that 700mah should work (at least if the battery is relativly freshly charged) (post 25)?

the question was: can you verify I can drive 4 cree's at 700ma with 3.6v input

quote Wayne:

"
Your input/output ratio is 3.6V:~14V or ~1:3.9

Simplified calculation is for the current knowing the Vin/Vout ratio and apply the same for the current. 14V@1A equal 3.9 X 1A to get the input Current = 3.9A. That's too much for the Shark. 14V @ 0.7 = 0.7 * 3.9 = 2.73A. That's possibly OK since we did not factor in the efficiency of the converter so input current will be higher than 2.73A by another 15% or so which will go over 3A again, but, not by much. So, 700mA is around the limit for the Shark in this configuration.
"