MC-E/P7 lights: full power from 1x18650?

[Fallingwater]

Browsing the usual sites that I shall not name, I've found a considerable number of lights that use the newer P7 and MC-E emitters and are powered by one cell. I'm not familiar with those emitters (yet), so I don't know how much power is necessary to drive them at full power. Is one 18650 feeding a driver enough?
I ask because I've had the general idea that 2x18650 lights would work better, but now I've seen the MC-E Trustfire TR-C2, which is small enough that one could consider EDCing it (the head is only very slightly wider than the body), but works on one cell only (obviously). I'm sorta tempted to get it...

 

[tsask]

I'm waitin on an ELECTROLUMENS 700 lumen P7.:whistle:
Getting ready to order a Wolf Eyes MC-E Sniper both run on 18650.

 

[bigchelis]

The next P7 single cell I purchae will be from Malkoff. Only if Surefire, Fenix, or Eagletac made these in a single cell I would purchase another P7 light.

It might be a hit and miss, but for $33 bucks at DX it's might be worth the risk.

 

[WadeF]

I'd love to see some Malkoff M60 MC-E's. Especially in a flood configuration, but they'd almost have to be flood. Hopefully someone will come up with some MC-E optics that can produce either a decent beam with throw, or nice even flood. For starters a MC-E with a small reflector to produce a nice floody beam with a good 400 lumens out the front should be possible while running off 2xCR123 or 2xR123. Going over 400 lumens out the front may run into heat problems in a P60 sized host, but I'm sure Gene will be able to figure out the limits of what is safe as he is always very attentive to heat management.

 

[ichoderso]

this cheap one cell lights have not a boost driver. the full/high brightness only in the first minutes and drops quickly and permanent. With half discharged battery, the current is only around 1A and you have the same brightness how a good Q5 flashlight.
but a nice floody beam and high brightness in the first time. You must charge your batteries often and you will be happy:grin2:

jens

 

[Lighthouse one]

I have one of the DX P7 lights, and the single 18650 holds full power quite well. Mine has a 5 mode 2800 ma driver.

 

[bluecrow76]

You don't get full bright on a single 18650 cell using the 7135 drivers for very long. I recently rebuilt my Lumapower MRV using a DSXOI P7 and a 2.8A 7135 sandwich (with protection diodes removed to reduce the voltage drop). The Vin on those drivers is limited to 4.2V. I am going to rebuild it with a Shark Buck and Remora. That will allow me to use a single 18650, or slap the extension tube on a go 2x18650 for longer runtime, plus access to a couple modes and hopefully better regulation than the 7135 drivers offer.

 

[Jarl]

this cheap one cell lights have not a boost driver. the full/high brightness only in the first minutes and drops quickly and permanent. With half discharged battery, the current is only around 1A and you have the same brightness how a good Q5 flashlight.
but a nice floody beam and high brightness in the first time. You must charge your batteries often and you will be happy:grin2:

jens

I beg to differ, it stays at about 2A throughout discharge (1 hour), easily out-lumening (lol) any other light I have until the sudden drop when the battery runs out of juice.

As long as you don't mind dodgy QC, they're pretty good lights :twothumbs

 

[txgp17]

Gene Malkoff + MC-E emitters + Khatod optic = flashlight happiness

 

[LEDninja]

Elektrolumens EDC P7 left ~2.8A, Ultrafire Q5 14500 right ~1A.

Left L-mini 1*18650 Q5 ~1A, right MTE 5 mode 1*18650 P7 ~2A.

From jtr1962's testing of LEDs at 1A.
Q5 237 lumens at 1000 mA (*1) & 288 lumens at 1400 mA
R2 270 lumens at 1000 mA & 335 lumens at 1400 mA
P7 328 lumens at 1000 mA & 440 lumens at 1400 mA (*2) & 581 lumens at 2000 mA (*3) & 741 lumens at 2800 mA (*4) (jtr1962 has not tested any MCEs yet but I figure The MCE & P7 is fairly close as they are both 4*late bin XRE dies.)
http://www.candlepowerforums.com/vb/showpost.php?p=2170040&postcount=141
http://www.candlepowerforums.com/vb/showpost.php?p=2412997&postcount=158
http://www.candlepowerforums.com/vb/showpost.php?p=2668288&postcount=229
*1) 237 lumens Estimated output of Trustfire TR-801 & Shining Neam L-mini & Ultrafire C3/14500.
*2) 440 lumens Estimated output of Trustfire TR-C2.
*1) 581 lumens Estimated output of MTE 5 mode P7.
*1) 741 lumens Estimated output of Elektrolumens EDC-P7.

Looking at the pictures of the Trustfire TR-C2 I am concerned at heat removal from the LED. With heat having long thermal paths through the front of the reflector and round and round the springs. I do not think the LED can be driven hard or LED life would be short. I would recommend using Low normally and go to High only when necessary on burst. Unfortunate the modes are High>Low>Strobe.

Hi (2800mA, 430LM) > Lo (1000mA, 100LM) > Strobe (1500mA, 200LM) is interesting.
Trustfire is claiming 2.8A on High yet only 430 instead of the normal '900 lumens'. From jtr1962's testing of P7s 440 lumens comes from 1400mA.
Trustfire is claiming 1A on Low yet only 100 lumens. From jtr1962's testing of P7s 114 lumens comes from 320mA.
I have a sneaking suspicion Trustfire is under-driving the LED to avoid heat problems and just claiming 2800 mA because people won't buy a P7/MCE light unless they see 2800 mA.

So a Q5 light is ~1/2 the brightness of the TR-C2 but with a better focussed beam. Unless you need lots of floody light I would stay with a small Q5 light like the TrustFire TR-801 or Shining Beam's L-mini. These lights are another 5mm narrower than the TR-C2.
Note there are problems fitting protected batteries into some L-minis.

Note also I am using LED lumens throughout this post.

 

[Fallingwater]

I have a sneaking suspicion Trustfire is under-driving the LED to avoid heat problems and just claiming 2800 mA because people won't buy a P7/MCE light unless they see 2800 mA.

Does anyone have a TR-C2 yet to confirm?
Thanks for the informative post, by the way :)

 

[tsask]

great post and pics! this makes my wait for my P7 a little more interesting!

 

[Fallingwater]

Hmm. I missed the fact that the light module is a P60 plugin. As far as I can determine, the metal body of the plugin itself constitutes the whole of the heatsinking. Maybe it can pass a bit of it through the reflector to the body, but I don't think it'd be significant.
This doesn't sound too good. How much heat can a P60 plugin body be expected to sink effectively?

The LED is probably underdriven to avoid heat problems. The light is still more powerful (and efficient) than any using a normal emitter, but not nearly enough to justify buying it IMO.
I imagine to get it to full power one would have to swap the driver and provide some way for the heat to pass from the P60 to the light's body. All in all, it seems like far too much hassle. Too bad, because I can't seem to find other MC-E or P7 lights in EDC format on the cheap sites, they all have big heads. I also very definitely can't afford custom jobs.

Hmm... might have to build my own out of an existing single-die design... how's the Trustfire TR-801 in terms of heat sinking abilities? Could it handle a quad-die LED going full blast? Would the narrower reflector even be enough for a larger quad-die LED?

 

[LEDninja]

Dereelight runs their modules at 1000 and 1400 mA but their pills contact the body directly.
The Trustfire looks like heat transfer will be through the 2 springs as well as the reflector. As I estimate only 1400 mA (see my previous post) it should still be OK unless you are using the light during a heat wave.

 

[Pöbel]

use the pill in a SF C2 (or sth. alike) without the spring. The Pill will directly have contact to the body as the body is exactly shaped like the lower brass part of the pill - kinda how the malcoff solution works. This will provide enough heatsinking. Not for 2,8A, but surely enough for 1.5A or even a bit more.

 

[FalconFX]

From the one major site that has a ton of P7 and MC-Es, I've got two lights from there, one of them being an UltraFire WF-1200L with a P7, and it's grossly underdriven, probably on purpose. There's heat generated on high after about 15 mins, but nothing to worry about, as the 1200L I got was surprisingly very well built. But it's being driven at 2.1 Amps. It outpowers my SureFire M6 (500lm), barely. But if I had to guess, it'd be somewhere only in the neighborhood of 600 lumens at the most.

If Wayne can drive that single cell P7 at 2.8A, just go with his EDC-P7... I've never been disappointed with anything from Elektrolumens.

 

[Fallingwater]

Can't afford a SF to use its body.

If Wayne can drive that single cell P7 at 2.8A, just go with his EDC-P7... I've never been disappointed with anything from Elektrolumens.

As I said, I can't afford custom jobs either.

It's gotta be either a refit of an existing design that I can do myself, or something from the usual two cheap sites...

 

[FalconFX]

Can't afford a SF to use its body.


As I said, I can't afford custom jobs either.

It's gotta be either a refit of an existing design that I can do myself, or something from the usual two cheap sites...

If you're gonna order from DX, go for the Aurora AK-P7-3 (SKU14212)... It's driven closer to peak. The one I gave my brother was driven at 2.62A according to my Fluke. It's not the 2.96A they listed, however I seriously doubt ANY P7 lights on DX are driven at 2.9A. It's brighter (and cheaper) than my UltraFire WF-1200L, but it doesn't throw as well. This one's a dual cell; the single cell one obviously will be underdriven much more.

You really need it to be at or more than 2.8 amps current draw in order to get it above 700 lumens. At this point, no 1x 18650 will ever do that from that site. The single cell Aurora quotes 2.0A. And if it's any indication, it won't even get to that either. But even if it was, from one of the data tables on CPF, if 2.8A gives you roughly 750 lumens, then at 2.0A, that should yield you about 540 lumens.

And runtime from a single cell with maximum draw to get you above 800 lumens would drain the battery in less than 40 mins, with dimming kicking in earlier. You'd probably have to pull 3.0-3.1 amps to do that, and most 18650s are at 2200ma capacity...

 

[Fallingwater]

This one's a dual cell; the single cell one obviously will be underdriven much more.

This kills it for me; I need it to be EDCable, and thus it must be a single-cell light.

And runtime from a single cell with maximum draw to get you above 800 lumens would drain the battery in less than 40 mins, with dimming kicking in earlier. You'd probably have to pull 3.0-3.1 amps to do that, and most 18650s are at 2200ma capacity...

LiIon cells are good for a maximum draw of 2C. A 2500mAh 18650 would therefore be ok with draws of up to five amps. I'm aware of the short runtime, which is why I need a multimode light. Ideally I'd want a dim mode for utility use and long runtimes (10+ hours?), medium mode for normal use and, say, a 2-3h runtime, and a "dazzle" mode for when I want a lighthouse in the palm of my hand, and who cares about runtimes then :D

In the end I reconsidered and ordered the TR-C2. I know it's underdriven, but I'm just too curious to see how much light it makes even at about half power.
I also have a little project for it. I still have to figure out all the small bits, but the general idea is to drive the MC-E at full power and solve the heat problem with forced air cooling.

I'll probably write a review of it when I get it, and a separate page for it if/when I mod it.

 

[kanarie]

In the end I reconsidered and ordered the TR-C2. I know it's underdriven, but I'm just too curious to see how much light it makes even at about half power.
I also have a little project for it. I still have to figure out all the small bits, but the general idea is to drive the MC-E at full power and solve the heat problem with forced air cooling.

I'll probably write a review of it when I get it, and a separate page for it if/when I mod i

please do,
I am very curious about this light!