Batteries for 2 Fenix Lights

The P series is advertised as taking only CR123As, but I thought RCRs were exactly the same except rechargeable, flatter output, and a bit less life. So can the P series take RCRs?

Also, just making sure, the L series can ANY type of AAs, right? Including alkalines, lithiums, Ni-Mh, and low self-discharge NiMh?

It seems like batteries (and performance on various types) may be the deciding factor between these two lights for me, despite my general disregard of batteries :ironic:

Nope. Rechargable Li-Ion are 3.7v, where CR123's are 3v. Some lights will take them, some won't. None of the 2-cell L series will take 2 Li-Ion. Some of the 1-cell ones will take one Li-Ion. The P1 and P2 series may loose low modes, but the P3D will work fine on RCR123's.

Perhaps if you post the specific light you are interested in we can tell you more.

The L series can take any of the AA batteries, the Li-ion ones will not work(well, the 14500 will work with the L1D but you loose lower modes).

Only the P3D can take rechargeables without loosing the lower modes.

The L1D, L2D, P2D all use the same head which only has the lower modes when input is under 3.2v.

A fully charged Li-ion battery is 4.2v and the 3.0V ones are about 3.6v fully charged so they won't work with the P2D and P1D if you want lower modes.

Also, AA lithium is 1.7v, which is fine, but 14500's is 3.7v. Same size, but very different. That's the difference between LiMnO2, LiFePO4, and Li-Ion chemistries.

Thanks for the clarification

I'm interested specifically in the P3D and L2D (both Q5).

So if I'm understanding right, the L2D will take all types of AAs except lithiums, and the P3D will take rechargeables. Seems like that is a pretty big advantage of the P3D, anybody know why Fenix isn't advertising it? On the same note, anybody know of a review with graphs of the P3D with CRs and RCRs?

The L2D will take alkaline, NiMH, and Lithium primary, such as the Energizer e2 Lithium. All those are AA's. A 14500 battery is "AA-sized", but is not an AA battery. Lithium Ion is a different beast.

Personally I prefer AA's since they are much cheap and safer (for nonflashaholics) to use and operate. With a couple LSD NiMH, you will never look back.

sorry for my ignorance... I feel like you're saying something pretty clearly but i can't understand the jargon...

So the L2D can use all AAs, but there are batteries that are the same size as AAs but are not AAs which it cannot use. Aren't there Li-ion (rechargeable) AAs? So can the L2D use those? Because it seems that Li-Ion are better than even LSD Ni-Mhs (correct me if i'm wrong).

Nothing about RCRs in the P3D? I'm looking a bit more favorably at the P3D with its increased runtime/output, but now thinking maybe more battery range would be worth a slight decrease.

Rechargable AA's are NiMH. They make a Li-Ion rechargable battery called a 14500 with is the same size and shape as an AA, and some flashlights like the Ultrafire C3 can use either (in one cell format only), but the L2D cannot. Very few 2xAA lights could use 2x14500 cells.

As for the slight decrease in brightness, you won't notice much of a decrease. Human eyes perceive eyes on a logarithmic scale, so it takes a large difference in brightness to notice much of one.

I'm not concerned much about the brightness decrease, but runtime decrease...

So energizer E2 Lithiums are 14440s?

No, e2 Lithiums are safe, 1.7v AA's

14500's are rechargable Li-Ion and are 3.7v

Li-Ion is rechargable, as is LiFePO4 chemistry
The e2's are LiMnO4, which is different.

Also, if you use RCR123's (rechargeable CR123's) in the P3D, you will LOOSE a lot of runtime. Using NiMH in the L2D, you will GAIN runtime.

OK, i get it now. Thanks for your help!

EDIT: hadn't seen your last post... But what about regulation? Is the gain with NiMh regulated?

It's actually a 14500 battery(14mm wide, 50mm long, cylindrical shape), I was not aware that there existed a 14440 battery. Thought there is a 10440(AAA sized, bit with 3.7v instead of 1.5v) battery. I think you were maxing those up.

All of the Fenix lights that I'm aware of are regulated. But to run the light on higher levels of illumination, you'll need to draw more power form the battery. Alkalines loose capacity when you try to draw lots of power from them. NiMh batteries also loose a bit of capacity at higher drain but much much less then an alkaline battery. NiMh and Lithium batteries retain their capacity much better then Alkalines at higher drain.

yeah, I know they're regulated, but very few regulation circuits work well for all battery types. Like you said, alkalines are an example. I'm just wondering what the graph of NiMh AAs would look like... many lights that are very well regulated with CRs or alkalines have nearly no regulation with NiMh.

Gunner12 said:

It's actually a 14500 battery(14mm wide, 50mm long, cylindrical shape), I was not aware that there existed a 14440 battery. Thought there is a 10440(AAA sized, bit with 3.7v instead of 1.5v) battery. I think you were maxing those up.

Click to expand...

Correct, I have edited my posts above.

Guess that shows which I deal with/prefer over the others...

I came to the light... said:

yeah, I know they're regulated, but very few regulation circuits work well for all battery types. Like you said, alkalines are an example. I'm just wondering what the graph of NiMh AAs would look like... many lights that are very well regulated with CRs or alkalines have nearly no regulation with NiMh.

Click to expand...

Generally, regulation is better with NiMH over Alkalines, as NiMH can provide higher current for longer, while alkalines sag in voltage under load.

This post shows some differences in a well-regulated light with NiMH, 14500's, and alkaline. Focus on the runtimes for the C3 Single (blue line in all graphs).

This one shows the difference between alkaline, NiMH and e2

Chevrofreak's L2D-CE and L1D-CE runtime graphs
Selfbuilt's AA Comparison + runtime graphs
Selfbuilt's Fenix Rebel VS Cree

I use 3.0v rcr123's in all my fenix lights that accept them, and the low modes work ok. The P1D-CE does blend the medium and high modes (only a slight difference in output) but low works fine.

Thanks for all the graphs - exactly what I was looking for

munkybiz_9881 said:

I use 3.0v rcr123's in all my fenix lights that accept them, and the low modes work ok. The P1D-CE does blend the medium and high modes (only a slight difference in output) but low works fine.

Click to expand...

Aren't RCRs 3.7V?