Lumens Factory D26 high output LED and which battery

Hey guys I need a bit of advice. I just purchased the Lumens Factory D26 high output LED drop-in for my Surefire M950 weapon mounted light. I typically only run (2) 123 primaries in this light but I'm curious if I have my light bored to fit an 18650 will I see any benefits from running a 2200 mAh, 2400 mAh, or 2600 mAh AW battery. The drop-in states, "3.6 - 13V regulated input for maximum flexibility". Do you guys think I would see longer run times by running the 18650 in it!?!
:thanks:

Runtime does seem to be longer with slightly dimmer output.

I hardly run my torches on CR123's anymore but my first test of the D26 LED showed this.

I have 2x of these LED's and one seems to have a much warmer colour than the other.
The warmer of the 2 develops a bad flicker at turn on with a 18650, this lasts a few seconds and then I think it drops out of full regulation.
The other one runs a lot longer before doing this.

shark_za said:

Runtime does seem to be longer with slightly dimmer output.

I hardly run my torches on CR123's anymore but my first test of the D26 LED showed this.

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+1

I'll have more runtime with long 3,7v cells but, say, "considerable" dimmer IMHO. I think the output rate will be around 100-120lms against 182lm peak [according IS 6''] running on 6v or more by 2 cr123 cells, or others.

Well this is my room clearing, warrant serving weapon mounted light. Its kind of a toss up which is more important. If the run time was fairly close I would have to go with more lumens! Being able to see the threat immediately is high on my priority list! Feel free to chime in!?!

I bought the seraph with this led. I was not impressed with the brightness with a 18650. The other day I tried 2 rcr123 and there was a noticable difference in brightness, some where in the middle of surefire p60l and a malkolf.

I was just about to answer your PM.. lol


the single 18650 will reduce the brightness, 2 AW 123's works great. I use that combo in my Z2. tailcap current is about .5A so you might get a little more than an hour of runtime there and full brightness.


If you want to use just a single 18650 then go for the 3.7V dropin. You'll get full brightness and some nice runtimes.

Superdave said:

If you want to use just a single 18650 then go for the 3.7V dropin. You'll get full brightness and some nice runtimes.

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I've got the 3-3.6V drop in and I'm quite happy with it. Just be careful as it seems to run in full regulation right til the Li-ion protection kicks in which could leave in the dark if you're not careful to charge them. The colour temperature is also quite nice on this drop in.

Thanks guys! I just got (2) AW RCR123's so when the lamp arrives I will test it with the RCR123's, 123 primaries, and the 18650. I'm curious!

Ok...as I sat eating my stuffed crust pepperoni pizza, which was awesome by the way, and drinking an ice cold Pepsi I realized there is alot about batteries that I don't know. I was always told that primary 123's are usually brighter than RCR123's. True or False. And why would two RCR123's give me more light than an 18650!?! I realize this post is beginning to stray off course but it is still relevant to my topic.

The problem with running 1 18650 on a regulator that's rated for 3.6-13V is that a single 18650 comes off the charger at around 4V, that low of an input voltage makes it hard for the driver to get the right voltage to the LED.

If you would like i'll test a few combos in my sphere so you can see the difference.

2 123 primaries would be just as bright as 2 rcr123's because both the total voltage and the total current available is within the range of the driver.

Policetacteam said:

...I realized there is alot about batteries that I don't know. I was always told that primary 123's are usually brighter than RCR123's. True or False.

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Answer is dependant on the voltage range of the drop-in.

Fully charged RCR123's have a higher voltage than a primary 123, which should equate to brighter output, assuming you don't your drop-in.

A primary 123 will give you more runtime, as their capacity is almost 3x that of an RCR123.

And why would two RCR123's give me more light than an 18650!?!

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Depends on the voltage range of the drop-in.

Two RCR123's will give you 7.4-8.4v, whereas a single 18650 will only give you 3.7-4.2v.

If you have a 3.7v drop-in and use a pair of RCR123...
That same drop-in will work fine with a single 18650 or a single RCR123 (with the right battery tube).

On the other hand, if you have a 4.2v-8.4v(or higher) drop-in, it will be brighter with the pair of RCR123 cells, but will start to dim and fall out of regulation once the voltage of a single 18650 drops below 4.2v.

I've found that RCR123's are usually brighter. Primaries are 3.0v. RCR's are 3.7v protected and up to 4.2v unprotected. The 18650 is the same voltage as a single 123. It does have about double the mah so it can power high drain engines, but otherwise it really only brings more run time. It's also safer to run a single cell than multiple cells because you don't to worry about matching them.

CR123s should never be brighter than RCR123 for practically anything. RCR123 has higher voltage throughout it's entire discharge, maybe in extremely high current if there is voltage sag?

Brasso said:

I've found that RCR123's are usually brighter. Primaries are 3.0v. RCR's are 3.7v protected and up to 4.2v unprotected. The 18650 is the same voltage as a single 123. It does have about double the mah so it can power high drain engines, but otherwise it really only brings more run time. It's also safer to run a single cell than multiple cells because you don't to worry about matching them.

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Unprotected vs protected should not have a different voltage. 3.7V is the "nominal" value of Li-Ion cells and 4.2 is the typical max recommended charge voltage. Your typical 18650 or RCR that says 3.7V comes off the charger at 4.2V. CR123 is lower than both RCR and 18650 voltage wise. The 18650 isn't too far off 2 x CR123 in terms of total watt-hours but it will run longer because as it's voltage tapers the driving circuit drops out of regulation. As it drops out of regulation, less current is drawn and thus the 18650's remaining capacity lasts a long period of time.

Alright...in a nutshell...thank you to everyone! That explains alot and actually made very simple sense!