Fenix and rcr123's

geoffg

Newly Enlightened
Joined
Sep 13, 2008
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Is it possible to use Rcr123's in a P1D, P3D and in particular an edc PD20 without any risk and will they keep all modes?

I also have a TK11 with protected ultrafire 18650s and find rechargeables a much better option as i seem to use around 3 Cr123s a week in the pd20 alone.

Tia Geoff
 
The P1D will loose its low mode and med will be closer to high with a rcr123.
 
I sold both my fenix's as i didnt think i could use rechargeables, the P1D and Tk10 ... i thought that i had read somewhere that its not recommended to use rcr123's in the P1D ... but i cant be sure ...
 
My PD30 runs fine on RCR123's, but my PD20 loses all the lower mode, just as Selfbuilt observed in his review.
 
Two-cell lights (ie. TK10, PD30, etc.) work just fine on RCR's.

The 1xCR123's will go into direct drive and loose lower modes.
 
Two-cell lights (ie. TK10, PD30, etc.) work just fine on RCR's.

The 1xCR123's will go into direct drive and loose lower modes.

Does this apply to the 3.0 v cells or just to the 3.7 v?
I have A PD20 also and have been wondering if the Tenergy 3.0 cells would allow all levels to work.
 
Does this apply to the 3.0 v cells or just to the 3.7 v?
I have A PD20 also and have been wondering if the Tenergy 3.0 cells would allow all levels to work.

3v RCR's would be fine, but I would avoid Tenergy cells like the plague.
 
Most people with 1 cell Fenix lights report a loss of low mode with a 3.7V cell, and report a brighter than normal low mode on a 3.0V RCR123 cell. Some people report burning out the electronics or the LED. (this is possible in some revisions of the 1 cell lights over the years, especially if it has a relatively low Vf LED).

I'm not a big fan of the 3.0V rechargeable options. Either you sacrifice energy density by going with LiFePO4, or sacrifice by wasted space and energy converted to heat with a voltage-bucked cell. both options have a lot of down-sides.

My recomendation when this question comes up (I'd estimate I've answered this question around 57 times in the last few years), is to sell the 1 cell Fenix lights as buy a competing model from another brand that offers 3.7V RCR123 compatibility. In the long term, this will simplify things. If you buy the charger and cells to make the Fenix rechargeable now, then in the future wind up buying different cells and different chargers for other lights, then there are possible dangers that can be introduced that are unnecessary. (Many of the chargers designed for use with the voltage-bucked 3.0V cells can cause a regular 3.7V cell to explode if accidentally put on the "3.0V" charger).

-Eric
 
Wow, thought my Fenix TK10 couldnt use RCR123's. About to order some spacers and some AW RCR123's. Would it be any brighter? :thinking: Or should I get an 18650? Will it even fit?
 
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Hello WHT GE8

As I recall, the TK10 will work fine on either 2 CR123 primary cells or 2 3.7V RCR123 cells. (must be protected or the unit can over-discharge them).

A single 18650 will not fit as a I recall

A single 17670 probably would fit but would not work correctly as the low-battery warning system would be constantly "on."
 
Ultrafire ICR123A 800mAh 3.0V cell
Ultrafire WF-138A charger (make sure to put it on 3V).


I'm going to use your post here as a teachable moment...

----------------

Based on looking at the various sales pages around the net for those ultrafire cells. Can anyone confidently proclaim to know what chemistry the cells actually are, and if they are appropriate for use with the 3.0V setting on a WF-138?

Everywhere seems to be just calling them a "3.0V rechargeable lithium cell."

It could be a voltage bucked LiCo, it could be a LiFePO4, or it could be a regular CR123 that will explode after 2-3 cycles.

---------------

This to me, would be a lot like pulling up to what you thought was a gas station, only to find out that the pump looks very plain, with no information about what comes out of the pump, no octane selection, nothing telling me that it is actually gasoline, just a sign over-head that says "fuel." Hmmmm.... What kind of fuel? Are you going to risk putting kerosene or diesel into your gasoline car? Obviously such a practice would be illegal in the states, but in China? Oh yes, you can buy all sorts of unregulated batteries sold with inadequate descriptions and specifications for safe use.

-Eric
 
I use 2x 16340 LiFePO4 cells in my Fenix PD30 and P3D. All brightness levels are retained, but the low cell indicator seems to no longer work.
 
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