# Pila GL4 550 - Problem, Disappointment, Questions for the Hive Mind



## technojunkie (Jan 5, 2007)

I have a number of high output LED lights, which are great, but I eventually got hungry for the power and throw of a big incan, so I recently purchased the new GL4 550. After playing for a few weeks, I've got some questions for all of you out there in flashlight land...

1. The GL4 is supposed to work at 550 lumens on four primaries (CR123) or at 250 lumens with two 600P lithium ion rechargeables. I purchased two new 18650 cells, which I thought were the same as 600P cells, but they do not work at all (i.e. no light). I tried both orientations and I have a clickie (not LED) tailcap. Primaries work fine. Any thoughts?

2. If there is any way possible, it would be great to get 550 lumens from rechargeables. Does anyone know if using four 3V RCR123a protected cells (such as those sold by lighthound) would be OK? Any other ways to accomplish?

3. Maybe I'm missing something, but it seems like 550 lumens is a lot less impressive than it sounds. I've compared the GL4 (running on primaries) to my Surefire U2, for example, and the GL4 definitely wins when illuminating a tree at 50-60 yards, but to my eyes the center spot is no more than 2-3X brighter than the U2 in that test. For short-range use, I would say the GL4 appears to have even less of an edge over the U2. The U2 is supposed to be 80-100 lumens, so I guess I was expecting the GL4 to be 5X brighter or more. Do my observations sound OK? Or is the GL4 nowhere near 550 lumens? According to Pila's USA distributor, btw, all of their lamps are tested at the factory on an integrating sphere.

4. Is there any chance that a Surefire M3 Millenium Combat with the High-Output Lamp Assembly would be brighter than the GL4 550? I realize that it's rated for lower output, but I wonder if perhaps SF tends to understate output while Pila perhaps overstates typical output.

Thanks for the help! I await your responses with great anticipation. Long live CPF!

Brian


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## greenLED (Jan 5, 2007)

welcome to CPF, technojunkie!

1. Did you buy Pila-brand 600P's, or cheap, no-name? Some of the latter do not have enough of a "button" on the battery to make proper contact - your light won't work with them. (People will jump in and recommend you use magnets to make a battery button - I *strongly* discourage this practice because of the risk of shorting out the batteries, which can lead to explosion).

2. I haven't heard of people using 4xR123's to power an incan lamp. As long as you match the lamp's voltage with what's coming out of the cells, *and* you aren't draining them beyond their maximum current rating, you'd probably be OK. That said, double-check with the hotwire guys.

3. Two issues: IIRC, Pila rates their output at the source, not out the bezel. There's a bit of light lost between the lamp itself and once it actually leaves the bezel. The other issue is how we perceive color temperature. LED's are mostly "cool" light sources, and we perceive warmer (ie. incandescent) light sources better.

4. I have no experience with the M3, but see my comment about how Pila and other manufacturers rate their outputs.


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## technojunkie (Jan 5, 2007)

The 18650s I bought for the GL4 are Tenergy 2200 mAh cells, which I assumed would perform equivalently to the Pila cells.

I also have a Pila brand 168A and, now that I compare them, it looks like the Pila is 1.5 - 2mm longer because of an extra button on the bottom side.

As far as I can tell, it looks like the GL4 spring and tailcap are making contact with the top and bottom of the stack of 18650s, but it is possible that the two cells are not making contact with each other in the middle. I will try a temporary fix to rule that out...


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## diesel_dad (Jan 5, 2007)

I have the same light and I am very happy with it.

I use 2 X AW's 17670 batteries, which come with the button. I had the same problem with the 18650 and concluded that magnets or button top cells are needed.

For the bulb, get a Lumens Factory E09L from www.lumensfactory.com. It's a 450 lumen 9 v bulb that fits the Pila and produces lots of brilliant white light from 2 X lithium cells.

You will flash the bulb with 4 X RCR123 since they will produce 16.8V total hot off the charger. YMMV.

Cheers!


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## technojunkie (Jan 5, 2007)

I wonder if there is a problem with using these batteries with this light. I just put both batts in series, checked for voltage with a multimeter, then conected them directly to the lamp assembly and... no light.

Is the protection circuit in the Tenergy cells different than in the Pila brand cells? Will I run into the same problem if I try to use four RCR123a cells?


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## technojunkie (Jan 5, 2007)

diesel_dad: I'm proposing the use of special 3V protected RCR123a cells, which should not flash the bulb because they, supposedly, limit the voltage at 3V. Do you know otherwise?

About the 9V bulb you recommend... have you found that it is brighter than the stock bulb? If not, why would I switch?


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## Paul_in_Maryland (Jan 5, 2007)

technojunkie said:


> About the 9V bulb you recommend... have you found that it is brighter than the stock bulb?


It should be far brighter. See these beam shots and various observations in the Lumens Factory thread.


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## greenLED (Jan 5, 2007)

technojunkie said:


> Is the protection circuit in the Tenergy cells different than in the Pila brand cells? Will I run into the same problem if I try to use four RCR123a cells?


If indeed those are protected, then that's possible. Part of the job of the protection circuit is to prevent over-current from being drawn off the battery. Some li-ion protected batts need a "double-tap" to get the lamp to light up.


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## Paul5M (Jan 5, 2007)

technojunkie said:


> Is the protection circuit in the Tenergy cells different than in the Pila brand cells?


Yep, I think they max out @ 2Amps. They're OK with a WE 12V LA (1.18Amps), at less brightness of course. But it can NOT power up a WE 3.7V LA (2.18Amps).
I think you can use them with a 320 Lumens LA (1.55Amps) from Lumens Factory.


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## woodrow (Jan 5, 2007)

I also have a gl4 550 and so far have just used surefire primaries. I plan on using lumans facory lamps (mike at pts will <is> be carrying them) shortly.

I posted beamshots vs my tl3 and light cannon hid. It is much brighter than the tl3, and arround the same brightness as the light cannon. The lc100 bulb is rated at 500 lumans, but from what I have read here, multiply that by 65% to get real world output. I know pila uses bulb lumans in their ads. 

Therefore, it should not be as bright as a m6 ho but about as bright as a m4 ho lamp. 

Jon at js burly's told me about a article he read stating that to the human eye, there is not much differance between 300 and 500 lumans at close range. The eye makes adjustments for brightness just like (better than) a camera set on automatic. At longer distances the brightness difference becomes more clear. That makes sense to me based on my tests.

hope that helps...
brad


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## technojunkie (Jan 5, 2007)

Paul5M, et. al: Do you think the Tenergy cells will work with the Lumens Factory E09L lamp? How do you know those battery specs?


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## greenLED (Jan 5, 2007)

technojunkie said:


> How do you know those battery specs?


We just make stuff up as we go. :laughing: 

Just kidding, there's loads of knowledge spread around CPF; it just takes a while to peruse the forum and absorb the tidbits. Check the "threads of interest" sticky on top of each forum section - those usually have a lot of meat and potatoes. 

ledmuseum.org, flashlightreviews.com, and the CPF Wiki are also great sources of reliable info. Again, welcome to CPF!


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## Paul5M (Jan 5, 2007)

technojunkie said:


> Paul5M, et. al: Do you think the Tenergy cells will work with the Lumens Factory E09L lamp? How do you know those battery specs?


Nope, the EO-9L sinks 2.4Amps. I don't have any specs. But based on my real world experience, the Tenergy cells can source at least 1.18Amps and less than 2.18Amps.


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## diesel_dad (Jan 5, 2007)

technojunkie said:


> diesel_dad: I'm proposing the use of special 3V protected RCR123a cells, which should not flash the bulb because they, supposedly, limit the voltage at 3V. Do you know otherwise?
> 
> About the 9V bulb you recommend... have you found that it is brighter than the stock bulb? If not, why would I switch?




Most RCR123's (like those from AW & others) are 3.7V nominally and 4.2V off the charger. I have measured. So, 4 X 4.2V = 16.8V. So, at $20/bulb I'd take a cautious approach.
There are some 3V RCR123's that AW and perhaps others sell, so they may be ok. I'd check with the voltmeter.
For 18650/17670 batteries, 2 X 4.2V = 8.4V -- so not enought to get a 12V lamp up to full brightness and white color. That's why you need a 9V lamp for that combo. It does not look any different to my eyes compared to Pila 550 lumen bulb and 4X123 primaries.
Have fun!


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## technojunkie (Jan 6, 2007)

Thanks for all of the info! It looks like I should probably get the E0 9L and some new batteries.

So:

1. Does anyone know the max current that can be drawn off the Pila brand cells before protection kicks in?

2. Anyone know of any non-Pila protected cells that will support the current draw?

3. Do you think I can remove the protection circuits from my existing batteries so that I can use them? Is that a bad idea?

4. How about using one of those 700 lumen 13V lamps in the GL4 with four primaries? Think that would be safe?


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## diesel_dad (Jan 6, 2007)

Ok, this morning I did test 2 X AW 18650 protected cells with one rare earth magnet (supplied by AW when I ordered the batteries) between the two cells and it worked just fine with my E0-9L bulb. So, the stock 18650's are just a little too short without the magnet. Maybe I will order a couple of Pila 168Ps next time but for now the 17670s and 18650s are both fine.

The issue with 2 X LithiumIon cells and the stock 550 lumen bulb is not current draw, it's voltage, so the current draw is likely not an issue. Also safe to say that 100 lumens of output difference would not be noticeable without a shoot-out.

Have fun!


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## 02Scuba (Mar 4, 2007)

Hi diesel dad !

I own a GL4 and I was very interested in the EO9L from the Lumens Factory. Checked the web-site and could not find the EO9L. I could not even find a 9 volt bulb. Are you sure it was the Lumens Factory ? Thanks.

Mike


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## GeorgePaul (Mar 4, 2007)

02Scuba said:


> I could not even find a 9 volt bulb. Are you sure it was the Lumens Factory


See 9V bulbs at Lumens Factory.


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## GeorgePaul (Mar 4, 2007)

02Scuba said:


> Checked the web-site and could not find the EO9L.


It's here.


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## max52 (Mar 4, 2007)

I have changed the configuration of my 12V GL4, Wolf Eyes 12v Turbo head. and Surefire M4. I am running 3 of new AW high current CR123A with a dummy. The results are really impressive. I had been unhappy with M4. Now it is great. I suspect all three are slightly over-driven, but I have not had an insta-flash.


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## max52 (Mar 4, 2007)

I forgot to mention that for my GL3, and other high current draw 9 volt applications, I use 3 of the Powerizer "3.0" volt R123a cells. These, again over-drive the lamp slightly and produce a distinct improvement in performance. The Gl3 is alot whiter, and brighter with the Powerizers.
They do not have under-current shut-off, so you need to recharge at the first sign of dimming. You also have to make sure the cells are balanced using cells that have been matched.


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