G2 BATTERY HELP

[longrange08]

hello im pretty new at this i just purchased a cree r2 290 lumen led for my g2 blowing thru 123A'S is going to get expensive so i was wondering what my best route is as far as batteries i think i can use a 17670 correct? but my night vision uses 123's also so unless it has a distinct advantage i would like 123 rechargable cells any advice anyone you guys havent steered me wrong yet thanks

 

[Black Rose]

A 17670 will work well, assuming the drop-in is geared for 3.7-4.2 volts.

It will still work if the drop-in is geared for wider voltage, but will likely run unregulated.

Also do you have a G2 or a G2L? If it's a regular G2, you're going to have heat issues with a 290 Lumen Cree.

If you want to use 123 rechargeables (16340 cells) that will also work and will work with the wider voltage range I mentioned above.
One thing to keep in mind is that 16340 cells have much less capacity than an equivelent CR123A primary cells (600 mAh for a 16340, ~1500 for a primary CR123A).

Also, 16340 cells are 3.7 to 4.2 volts, whereas a CR123A primary is 3 volts. Make sure what you are going to put them in can handle the extra voltage.

 

[mdocod]

The 17670 may be the best solution if you don't mind taking a hit on output...
Before I "shock" you with the output hit.... consider the following:

*Pretty much all of the "270, 290, 300+" lumen rated R2 modules sold out there on ebay, dx, kd, etc, are right around 175-200 true torch lumens.

*if you run the module on a pair of 3.7V protected RCR123 cells (AW brand recommended for reliability/safety/and fitment), then you will get that 175-200 lumen output through a continuous run of about an hour, at which point it will suddenly shut off with no warning with dimming or anything. If you are on a stock G2 with plastic head, you will need to limit continuous runs to about 5 minutes each to prevent the lamp assembly from over-heating and destroying the LED.

*if you run the module on a single 17670, worst case scenario it will start off around 100 lumen and diminish to around 50 lumens in ~4 hours of burn time. (some modules will vary here, depends on which specific one you have).. The lower output is not as *bad* as you might think. For one thing, the lower power consumption means that if you have a regular G2 (plastic head), you don't have anything to worry about along the lines of heat buildup. I have run the 11836 (popular "super-bright" D26 LED R2 module) continuously on an 18650 in a plastic host without any problems with heat (module gets warm but not hot). Also, "doubling" or "halving" output only looks like a "step" difference in output to the human eye. It's not as "big" a deal as you might think looking on paper. When the cell is fully charged, it's actually hard to notice a difference between an 11836 running on a 17670 or 2 li-ion cells unless you compare them side by side. It's when you run the single li-ion cell down a ways (~50 lumens) that you can start to see the difference pop up more dramatically.

-Eric

 

[longrange08]

thank you for your help that was exactly what i needed