Question on 3V rechargebles

Paul6ppca

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I wnt to use 3 V rechargable for my Fenix PD 10,Whats the difference between Tenergy lifepo4 750ma vs tenergy 3v rcr LI on 900ma. Are thier Ma ratings accurate? What would be the better choice.
 
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no the ratings are all BS :) This all assumes where talking about Rechargables and not a lithium primary, which should Never be charged ever.

the li-fepo will be concidered the "safest" and will have very poor capacity.

a Regulated 3V li-Co type will require a special charging capability, assuming it is an actual regulated li-ion.

Neither of them should be charged with a regular li-ion charger unless it has the switch for 3V. and you should know the huge differences between the li-Fe and a regulated Li-ion before charging them.
and there can be a huge differance in a chargers opinion of a 3V cell, having a switch for it.

a regulated one acts like this
+-.7V--{==]--
while the internal battery is a li-ion standard going from ~2.5-4.2v there is a ~1/2 volt SLOP that goes on.
so it gives you about 3V even though it is a 3.6v cell, and you charge it at a HIGHER voltage because of the slop.
to read the voltage with a DMM you should put any lightweight load on the battery.
a regulated one has about as much power as a raw li-ion, and on some lights it helps runtime that it is regulated, even though the 1/2volt is discarded.

a Li-FE is a battery chemistry that has actual lower voltages, while it will seem like you can charge it with regular li-ion charger. its charge voltage is way lower .
it has about 60% of the capacity of a li-ion, and needs no regulation, and does not come with a curcuit for protection or regulation (usually)

some 3V LISTED/SOLD batteries are not 3V nominal at all, and can be just raw or protected li-ion cells , so you gotta watch out what you get.

my most favorite regulated li-ion cell item to date listed properly as a 3.3v RCR123 is an Orange and white powerizer, which seems to also include actual protection not just regulation, and has lived a long fruitfull life.

and that is the most simplistic splaining i can do, without you asking more questions.
 
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The Tenergy 900mAh cells are as Vid described. They are regular LiCo cells with two diodes incorporated into the cell. This reduces the voltage of the cell when under load to ~3 volts (actually, depending on the load applied, usually somewhere between 3.2 and 3.6 Volts). As Vid said, it also means that to properly charge the cell, you need a different charger than regular LiCo cells use (4.20 volt) to overcome the effect of the diodes. Most chargers intended for charging this type of "voltage reduced" cell, charge to 4.4-4.5 Volts. This means that you cannot use a LiFe charger to charge "3 Volt" LiCo cells either, as they are typically 3.6-3.8 Volt chargers. Most chargers that I am aware of that have a selectable 3, or 3.6 Volt setting, are for LiFe, or LiCo cells respectively, and are not intended for charging "3 volt" LiCo cells.

Tenergy offers specific chargers for all three kinds of cells. You just need to make sure you have the correct one. The most dangerous combination, is attempting to charge an unprotected regular LiCo (4.2 Volt) cell in a charger that is intended for a "3 Volt" LiCo cell. This combination will charge the cell to a potentially dangerous voltage of 4.4-4.5 Volts.:poof: Attempting to charge a LiFe cell in this same charger, will likely only shorten the life of the cell due to overcharging.

Charging 4.2 Volt LiCo cells in a LiFe charger will result in practically no charge to the cell and charging a "3 Volt" LiCo cell in either a LiFe charger, or a regular LiCo charger will result in basically no charge, and typically less than a 40% charge respectively. So again, make certain you use the proper charger/cell combination.

Dave
 
The tenergy lifepo batteries are okay imo, Yes they have lower capacity, but as a 3v cell, they are pretty good. With about 3.2v charged, and under 3v under load, it works quite well. You can get packs of cells that come bundled with the specific charger.
 
Thanks guys for all the info.I do understand that i will need another charger just for either of these batteries,
I am still unclear if there is a performance advantage to either.Which will have better runtime and will there be any decrease in brightness?

Heres is the kit I am looking at; Combo Kit: 6 RCR123A 3.0V 750mAh LiFePO4 Rechargeable Batteries with a Smart Charger
Please let me know what yuor opinion of these cells.

Thanks
 
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The 3 Volt LiCo cells are likely to provide considerably longer runtime than the LiFe cells. The highlight of LiFe cells for me anyway, is that they have a much longer expected lifetime (longer shelf life, 10 yrs as opposed to 5 yrs for LiCo). Also, they are said to be rechargeable around 2000 times, as opposed to 300-400 for typical LiCo cells. This more than makes up for the reduced capacity, in many ways.

In addition, LiFe chemistry Li-Ion cells are much more resistant to abuse than LiCo cells, do not rely on any electronic circuitry for either voltage reduction, or "protection", so there are fewer things to go wrong with a LiFe cell, and there is less safety concern when running LiFe cells in series applications, as well.

Keep in mind that 900mAh for a 3 Volt LiCo cell, and 750mAh for a LiFe 123 cell are totally outrageous numbers. The 3 Volt LiCo cells are probably about 500-600mAh, and the LiFe cells are most likely around 350-400mAh. That's just a guess, I've never had any Tenergy cells, but from my experience with other RCR123 3 volt LiCo (Powerizer and AW's) and LiFe cells (various DX et al), that is what I would expect.

Dave
 
brightness is the same with the usual Boost curcuit, as the voltages of both are being boosted.
Unlike an unregulated li-ion which can pound some of the boost curcuits designed for 123s , and be very bright and be toasting the led in them. ( i run a few this way carefully in thier "direct drive")
and
this light Fenix PD 10 would be similar, in that it would be very bright with a unregulated and give the possibility of frying it dead.
you make A Wise choice getting one of the lower voltage alternatives , but still rechargable.

If the light was some amazing Hotwire :) or trying to push a 12 watt led then pick the Li-FE because it will cope with more amperage at a time, but not that much.

with li-fe i would want to carry a spare, and thankfully that can be done more safe :) i prefer the regulated li-ion for the runtime advantage.
 
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Found this info in a Fenix pd10 Ti thread;

"Most of the ones I've tested lose the low mode and is at the same output as the medium level.

I've pretty much purchased every single "3v rcr123a" and tested them all. They are NOT up to snuff. There is VERY good reason I do not carry them. Let me educate you.

1) They're really not 3v's. They're actually 4.2v without load (so they will fry low power electronics - i.e. cameras that use cr123a). Under load they are 3.3v to 3.5v. Still not good. They'll blow some of your expensive incandescents.

2) They actually use an LDO circuit to "regulate" the voltage under load. This means it simply acts like a variable resistor. So imagine, the LDO is actually dropping up to 1v. At higher currents that's a lot of energy wasted! I've pulled out cells after being under heavy load and the battery is hotter than the light!

3) Their capacity is abysmal at best. They are as bad as 1/2 the capacity of the awrcr123's that I sell and as bad as 1/4 the capacity of lithium cr123a primaries."

and this

"Got my PD10 Ti today, and using AW LiFePO4, there is no low mode (although my battery is recently charged), and on high there is a pretty audible high-pitched electronics whine."

Thanks for the info guys ,but I think I will stay with primarys.It seems like the best choice for this light.
 
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Thanks for the info guys ,but I think I will stay with primarys.It seems like the best choice for this light.

Heh, yeah, there can be repercussions with cells that are higher voltage than what the light's circuit is designed for. I guess I was only attempting to answer the first two parts of your original question, sorry about that.

The only Fenix light I run RCR 3 Volt LiCo cells in, is a P1. It does run a bit brighter with a 3 Volt LiCo than with a primary cell, but more noticeable than that, is that it runs noticeably warmer, as well. No problems in 5 or so years though.

3) Their capacity is abysmal at best. They are as bad as 1/2 the capacity of the awrcr123's that I sell and as bad as 1/4 the capacity of lithium cr123a primaries.
I have to say that as far as the 3 volt LiCo cells that I've used (not Tenergy's), they do quite a bit better than that, but are still less capacity than an AW RCR123 cell. The rest is true however. LiFe cells struggle to have half the capacity of LiCo cells, it's just the nature of LiFePO4 chemistry. Also, LiCo cells in general, are only about half the capacity of lithium primary cells, at best. Their higher voltage offsets this substantially though, the actual "power" (Wh) thus, is a bit better than that.

My use of either LiFe, or "3 Volt" RCR123/16340 LiCo cells, is limited pretty much to lights that were designed for the use of lithium primary cells. In addition to the aforementioned Fenix P1, I also use them in various Peak single 123 lights, as well as 2x, and 3x 123 lights. The later, anymore, run on 17670, or 2x17500 cells though. All of my other 123 lights were designed to run on 4.2 volt RCR 123 cells, so I don't have problems such as the loss of features etc, with them.

Unfortunately, if you want your Fenix to work as it was meant to, I think you're making the right choice, expensive as it is. This is one of the reasons I quit buying Fenix lights long ago.

Dave
 
"All of my other 123 lights were designed to run on 4.2 volt RCR 123 cells, so I don't have problems such as the loss of features etc, with them.

Unfortunately, if you want your Fenix to work as it was meant to, I think you're making the right choice, expensive as it is. This is one of the reasons I quit buying Fenix lights long ago."

Dave[/QUOTE]

I agree,this is my only Fenix light with primary cr123,I really liked its size and UI, as well as the smoothest twisty Ive used. So I feel its worth the effort and money to buy primarys. I seem to only use 1 a month so the cost online is about $12 /year I can live with that.

All my other lights, like yours run on some kind of rechargable, and are designed to run on RCR 123. I too stopped reading about Fenix because of the lack of support for RCR batteries.

BTW have you ever used 3V rechargable and lost some/all modes?Im just curious if its likely to happen in most lights.

Thanks for all the info!
 
BTW have you ever used 3V rechargable and lost some/all modes?Im just curious if its likely to happen in most lights.

All the single cell lights that I have, that are "multi-mode" are 4.2 Volt capable, so can't help you there. I only use 3 Volt Li-Ions in single mode lights. Reading the Forums though, I think loosing some of the functions of multi-mode lights that are not setup for 4.2 Volts, is quite common.

Dave
 
Isn't the Fenix the only one to lose modes? I thought all the rest just ran too hot (or died) with 4.2V input.

I use old AW LiFePO cells in my Inova X03 and Arc LS. Bought 'em for a Surefire A2 but they don't fit, and even if the did I'd get, what, 20 min of runtime?

I'd like a keychain LiIon light and have considered the Quark Minis. But, they have a runtime on hi of just about 30min and that's pushing LiCo cells harder than I'd like. Better than 10440s in my L0D but still, a regulated 1A on hi would be my ideal.
 
I'd like a keychain LiIon light and have considered the Quark Minis. But, they have a runtime on hi of just about 30min and that's pushing LiCo cells harder than I'd like. Better than 10440s in my L0D but still, a regulated 1A on hi would be my ideal.

OK, OT, but I have three AAA keychain Lights that are 10440 capable, an old LiteFlux LF2 (SSC P4) and two old MJP Extreme III's (same UI, different electronics). Both of these lights will run really hot on 10440 cells on max output. Mike (ARC mania) said he didn't recommend 10440's for any extended runtime on max anyway, for fear of burning out the rebel 80/100, and I'm sure the LF2 isn't much different.

That said, the drive current to the LED with 10440 LiCo cells is around 600mA, if I remember correctly, so that would be well under 1A from the 10440, probably ~700mA I'm guessing. This is over 2C from the 10440, but not too bad for short runs anyway. I'm not sure what the newer LiteFlux LF2xx's drive the emitter at, but I doubt if it's any more than that, so you'd be well under 1A, I would imagine. And, keep in mind these lights are designed to run on Li-Ion cells.

The runtime however is of course, very short with an AAA/10440 light, on max. I have mine setup for 15% drive current on P1, and 100% P2, but you could reduce the P2 to 80%, or even less to extend runtime, as well as reduce heat. The difference in brightness between a drive level of 70% and 100%, for example, is barely noticeable.

Dave
 
Well Ill risk a bit OTness... tho to start I had a real surprise with 3V 123s. To wit, I have a few LiFePO4 AW 500mA cella Ive used for years in a 3.0/3.6 switchable WF-138A RCR charger.

I ordered (and am trying to cancel) some Tenergy 750mA LiFePO4 cells that for some reason have a warning about not using the WF charger. Not sure why, something about them being LiFePO4 with a series .2V diode? Strange and very confusing even with warnings.

So, anyway, got an A1 and LiCo RCR to try together. Dunno if Ill like the larger diameter keyfob but at $25 I'm keen to try. 4sevens new S2 emitter MiNI 123 is probably as bright with LiFePO4 as the Q5 A1 is on overdrive with LiCo, but, oh well. I just want "a lot" more than the 70-80 L0D NiMH on my keychain in case I can deal with the size.

That is 3.7RCR on edge at 2C, but pulling my spare 10440 out I get 1.15A on high out of a ~300mA LiCO cell, pushing a unacceptable 3.5-4x C discharge rate. Why I quit using them.

Anyway, hoping to get a massive upgrade in keychain lumens here with any light or Li battery setup.

Think I'm going right direction?

After this maybe looking to upgrade to fancier versions, RCR123 or 10440 keychains with R5 or better emitters.
So far other than the old LF2, I can't find any LiIon keychains with overdischarge protection. No new 10440 lights, and the few RCR123 (ra,novatac) are larger EDC but not keychain lights.

Anyway, advice or comments appreciated.

My expectation is Ill end up as before, wait for a 1xAAA NiMH or li primary AAA that can put out enough more than the L0D-CE 70 to be worth upgrading (140lm would do it). I don't think the S2 Preon is quite enough but maybe next bin or two in the future.
 
I ordered (and am trying to cancel) some Tenergy 750mA LiFePO4 cells that for some reason have a warning about not using the WF charger. Not sure why, something about them being LiFePO4 with a series .2V diode? Strange and very confusing even with warnings.

Hi rad. I'm curious, where did you hear this? While I don't own any Tenergy "750mAh" (That's a joke) 3 volt RCR123 LiFe cells, as far as I know they do not have any diodes incorporated within the cell. They should charge just fine in the WF-138, set to "3 Volts".

I frequently charge 17350 and 15270 LiFe cells in a WF-138, when not using my hobby charger. It sounds to me like your source of information is perhaps confused. The Tenergy "900mAh" (another joke) 3 Volt RCR123 cells do incorporate diodes within the cell, as these are LiCo cells. Maybe that is where the confusion stems from. The "900mAh" cells would not charge very well in the WF-138, unless you set it to "3.6 Volts", in which case the cells would charge, but not fully (only to about 40%).

As for your desire to get more output from a keychain light, I don't own any of the lights that you mention. Keep in mind though, that while using a LiFe cell will keep the voltage down to possibly, a more manageable limit, these very small AAA/10440, or even CR2 lights, will get very hot when driven at high levels. Even limiting the use to short bursts can overheat the LED and electronics very quickly (undetectable from the outside) in such small lights. Probably you're best bet, is to do as you suggested, and wait for a higher efficiency LED to use in these lights.

Dave
 
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