Mini Review Of The 900L P7 LED Conversion Head

qarawol

Enlightened
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Jan 16, 2004
Messages
380
Location
Southern California
This is a mini review of the 900L P7 LED Conversion Head that fits the Surefire M series body. I was willing to try one out and wanted to see if it can do what it claims. Do an eBay search for " Surefire 900L " - there were a couple listed at the time of this writing.

It was mailed in a plain bubble type envelope that was in a USPS Priority Mail envelope that came from CA, USA. My first impression was… eh! The finish is a dull bead blasted looking olive drab. I am not sure if it is actually hard anodized but I tried scratching it lightly with a key and nothing. I didn't want to deep scratch it on purpose yet; I will let time do its thing. The color matches the Surefire SW02 switch but without the glossiness. The reflector looks decent and it has a light stippled finish. The base of the reflector, where the LED is, is flat with a diameter of about 1". The LED seems dead center and the yellowish reflector glow appears uniform but there is no reflection of the LED on the flat area, it remains silver in color.

Angle.jpg

Side.jpg

BusinessEnd.jpg

100_2174.jpg



The OAL is 79.85mm (3.114"). The bezel is lightly crenulated and has an outside diameter of 53.91mm.(2.122") at its widest and has a nice clean shape down to the cooling fins. The glass window is 1.84mm (.0725") in thickness and has a diameter of 50.8mm (2"). It is not coated in any way. I didn't remove the reflector for it did not drop out on its own. There was a thin o-ring between the reflector and inner edge of the head. I didn't want to chance scratching the reflector should I slip in removing the o-ring with a pick or the o-ring popping out touching the reflector leaving a smudge..

The back of the head has the standard 2 spring contact points. Center spring (+) is silver and the outer spring (-) is gold. Not sure if it is 'gold' plated though I doubt it. The springs can be pulled out of the base quite easily and I don't like that. The wires remained attached but I don't see any solder on the wire/spring contact point. It could be spot welded.

The threading looks good and it fit with no problems. It was a very nice feel screwing it on an M3/M4 body. It made very good contact with the o-ring and felt like it should give a proper seal.

The rated operating voltage is 9-12vdc. This means it can be used with three or four CR123 primaries or three 3.7v RCR123 rechargeable cells.

The beam pattern is very impressive for a medium cost wanna be high end accessory/mod. The hot spot has a soft outer edge that feather out to the side spill. It seems to be dead center and the side spill has the hexagon shape of the bezel. There are no dark spots or artifacts in the beam. This to me shows that everything is lined up properly and seems to be pretty well built. Though I don't know what the inside electronics looks like.


Camera shutter @ 1/320 sec beam pattern...

BeamPattern.jpg




I compared this 900L P7 to two other Flashlights that I thought would be a good comparison. The Surefire L6 and the 'ARC mania' SF-V 3 cell in Black HA… the only one in existence. All camera setting were the same for these 3 beam pictures and was set at 1 sec shutter, ISO50, f2.8, tripod mounted with 2 sec timer used for a steady shot.

L to R * Surefire Z3 w/900L P7(3xRCR123) * SF-V(3xRCR123) * Surefire L6(3xCR123)
Candidates.jpg



Surefire L6…
SurefireL6.jpg



900L P7 Head…
900LP7.jpg



ARC mania SF-V 3 cell…
SF-III3cell.jpg


The beam for the L6 in the picture looks like it needs to go to the doctor to get fixed up. I took the picture twice and it was the same. I doesn't look that bad live but I have to use what the camera sees. The L6 tint is on the greenish side. The 900L P7 kept up with the SF-V… NOT! It did run a middle second though. The pics don't do justice in the real world of beam shots. I have yet to see one beat the SF-V in its size/power source category. If the SF-V is rated at around 1000 lumens then the 900L P7 maybe putting out what it claims.


Current draw on 3 x CR123 (9.13vdc) = 2.08 amps
Current draw on 3 x RCR123 (12.25vdc) = 0.87 amps

Amp readings were taken at the 5 sec mark. Meaning, once I hooked up the meter and the light came on, I counted 5 seconds and what ever was displayed on the meter at that point is what I recorded. Unknown if this head is reverse polarity protected and no I didn't want to try to see if it was.

Using 3 x RCR's it ran for 24 min before dimming to a very low low. I immediately turned it off and back on again and it went right to full brightness. 20 seconds later it dimmed again. I did it one more time and this time it remained on for 30 sec before dimming. I stopped and turned it off. I don't know if it could be the battery protection starting to kick in or if the head has a temperature sensor. It turns back to full brightness again immediately but I just turned it off. I didn't want to hurt anything. The outside temperature of the head was 116.5 F. It was very warm to the touch but manageable.


And now for some Flashlight porn with this 900L P7 head on some sexy bodies…

Surefire M4 body…
M4.jpg



Surefire M3 body…
M3.jpg



FM 2x18650 body…
FM2x18650.jpg



And my favorite… the Surefire Z3 with a C to M adapter and an SW02 tail…
Z3.jpg



Size comparison group hug…
Size.jpg



Would I recommend this head?,,, YES! It is a definite go in my book for a quick easy medium cost upgrade (for what you get) for the M series Surefire Flashlights or any M series threaded body you may own. Just don't exceed the 12v maximum. Reliability and longevity remains to be seen.


Njoy…
 
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Thanks for this - it looks interesting, and certainly makes the L6 look a bit blue and feeble. Price?

I'm moving this to the Reviews section.
 
**UPDATE Jan 12 2009**

When I kept swapping out the head onto different bodies, I kept hearing the spring grinding on the inside if the body = normal. Remember me mentioning that the spring could come off easily and I didn't see any solder on the contact point?... Well here is why.

Spring.jpg


The spring would seem to bind on the inner body and stop turning yet more turns were needed to fully seat the head. It turned that all the on and offs I was doing of the head, finally revealed a problem. The wire was slowly moving up the spring. It was not soldered in place, only wrapped. There was nothing locking the spring to the base and it would free spin as the head was turned. NOT ACCEPTABLE! Here is a quick cure for the problem.

I carefully removed the spring from the base and disconnected the unsoldered wire. I then used two needle nose pliers and bent a small portion of the base end 90 degrees inwards. This will sit in the slot of the base and prevent the spring/base from free spinning when mounted on a body.


Pics…

Springa.jpg

Springb.jpg

Springc.jpg


A little dap of solder and all is well. The spring no longer spins freely.

So I guess I have to change my recommendation for this head. If you like to tinker, then have at it otherwise, leave it alone for that spring/wire issue can loosen up enough to cause a dead short and we all know how lithium batteries would just love that… don't we?

Njoy…
 
Looks good, but I didn't notice who its from.

Link please!!

Thanks,
bigC


Please do a " Surefire 900L " search on eBay. There were two sellers... one in CA USA and the other in Taipei Taiwan. I didn't want to post the actual link for it would be dead in a few months and I wasn't sure if posting an auction link would be appropriate on a review thread.


Thanks for this - it looks interesting, and certainly makes the L6 look a bit blue and feeble. Price?

Tru dat on the L6. I need to send it in for repair.

I won my 900L P7 for $86.00. There is a link on one of the auctions that sells it on their website for $189.00.

Njoy...
 
The rated operating voltage is 9-12vdc. This means it can be used with three or four CR123 primaries or three 3.7v RCR123 rechargeable cells.

[...]

Just don't exceed the 12v maximum. Reliability and longevity remains to be seen.

3x16340 Li-ions fresh off the charger can give you 3*4.2V=12.6V before sagging to their quasi steady state voltage under load. If one used this head on a SureFire M6 with 3x17670 holder, there probably would be even less voltage sag than with 3x16340 used in your testing. It would be useful to know more details on the nature of the 12V max input voltage limit. Is it just some random number, a value based on the recommended datasheet limit for some driver component, or a value based on an absolute datasheet limit for some driver component? Lacking any other information, I would have to assume that there is a potential long term reliability issue.

It also would be nice if someone could do a head-to-head comparison of this TurboHead vs the Lumens Factory Seraph P7 TH, goinggear.com MC-E TH, and OpticsHQ TX3 TH.
 

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