18650 Question

[Hitthespot]

First off I'm learning this rechargable stuff as fast as I can read every night. If any thing I state is incorrect please correct me.

I have a number of (2) CR123 based lights. I believe the Lithium Ion replacement for that is the 18650 which is approx 3.7V.

1) Does this battery reduce the output in either/or LED/Incand lights since the the voltage is reduced from 6.0V to 3.7 Volts.

2) Is there more or less Run time with the 18650 vs 2 Cr123 Primary batteries.

3) I just purchased and am waiting on the Pila charger for recharging my 14500 batteries. Do I need spacers. The 18650 battery this charger is made for should be longer? Correct?

Thanks in advance, I'm learning as much as I can from the searches but sometimes it's just easier to ask.

Bill

 

[mdocod]

1. depends on the light, many won't fit 18650s, some won't work right on 3.7V at all.
2. Same answer as #1.
3. Yes, you will need ~15mm spacers

 

[Hitthespot]

Surefire E2e
Olight T20-Q5
SureFire G2 w/ Bugout gear Q5

EDIT: Found the spacers at Lighthound. Thank you very much.

Bill

 

[mdocod]

E2E:
18650 won't fit, install a 17670 and a LumensFactory E1R series bulb (HO or EO). Or run 2x3.7V AW protected RCR123 and an E2R series bulb (HO or EO).
My personal recomendation would be the 2x3.7V AW protected RCR123 and a EO-E2R bulb. Incredible brightness and whiteness for the size.

T20:
Sorry I'm not sure if this light works best with 2xRCR123s or 1x17670, but I do know it doesn't have room for an 18650, sorry. Hopefully a T20 owner can give you some insight.

G2 w/Bugout:
The bug out gear drop-in is not suitable for single Li-Ion driven applications, from what I can figure, it drops out of regulation below 4.5V. You will need to run this one on 2x 3.7V RCR123s. Sorry


With any luck, this thread can serve as a learning tool. If you have even the slightest feeling that you might want to go rechargeable with your lights in the future, buy 18650 ready lights from the get go. Look at DereeLight, LumaPower, Wolf-Eyes, Pila, and countless others offering 18650 compatible lights with more runtime and boost/buck regulation in similar sizes as the lights listed above.

 

[matrixshaman]

Yes the 17670 is essentially the same size as 2 x CR123's whereas the 18650 is bigger. If it's an LED light most that use 2 x CR123's will probably work on one 17670 but not necessarily all. My Surefire L4 seems to work great on this battery and I don't think I can even see a difference in output over 2 x CR123's.
An incandescent bulb made to run on 6.0 volt will be very dim on 3.7 volt regardless of how much current or power is available in the 18650 or other rechargeable. It takes voltage close to the bulb rated voltage to make it bright.

 

[Hitthespot]

Thanks gentlemen, appreciated!

Very educational. I'm sure others new to all this rechargable information will get something from this thread also.

Bill