IFR16340 help

[Katherine Alicia]

I just bought some IFR 16340 (cr123a) cells and it says these are 3.2v batts, I`ll hopefully be using these in my P60 hosts because I refuse to buy single use batteries, but I have questions! LOL

1) is the 3.2v literal? as in that`s what they are when fully charged, Or is it like 3.7v Li-ion cells that are really 4.2v
2) since they`re only 3.2v what`s the max discharge cutoff voltage?
3) can I charge them on a regular charger that does Li-ion and NiMH cells or do i need a special one for Li iron phosphate?

anything else you think I might need to know when using these in a P60 Incan setup?

 

[adamlau]

3.2v nominal, usually comes off hot around 3.7v or even higher (if cycle life is not imperative). Around 1A max discharge. No special care other than trying not to discharge under 2v per cell for cycle life.

 

[Katherine Alicia]

Hmmm... seems like they`ll still be too much when freshly charged to run a 6v bulb module without popping it then

 

[xxo]

You need a special charger or a charger with a stetting for them. Voltage is too high for incan bulbs.

 

[Katherine Alicia]

I have a charger that will charge to either 3.7 or 4.2 if that`s any good? Ironically it`s the first charger I ever bought!

 

[xxo]

Seems like it would work, though I think IFRs are charged at 3.6V. You need a low charging current (around .25 A).

 

[Katherine Alicia]

You need a low charging current (around .25 A).

yeah, That`s gunna be a problem, it`s a 500ma charger

 

[xxo]

Probably a little too high of a charge rate for 16340's with typical 400-500 mAh capacity, but you might get away with it.

 

[aznsx]

I don't know what kind you bought, or of course the mfgrs. specs, but here's a link to a post with a link to the specs for the ones I use. You may find them interesting / enlightening if you haven't used the chemistry before.

https://www.candlepowerforums.com/v...r-6P-classic&p=5411936&highlight=#post5411936

 

[Katherine Alicia]

well I figured if I`m going to be doing this, then I may as well do it properly from the start, so I bought a charger for IFR cells as well. Worst comes to the worst I have several LED lights I can use them in so there`s nothing wasted.
The batts I bought are by Poover here: https://www.ebay.co.uk/itm/4-x-POOV...e=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649
I`v had batts by them before and they seem to be ok, and are still working fine a year later (even though I`d never heard of them before).

I`v read in a few places that if you leave these batts to rest for an hour or so, they do drop in voltage and tend to stabilise at about 3.35v (ish). so Now I`m wondering if i`ll have a few spare mm in the tube so that I can solder a couple of 1A diodes in parallel between 2 sheets of copper clad board and use that as an insert to drop the excess voltage, like: 3.35 x 2 = 6.7v - 0.7v = 6v.

 

[ChrisGarrett]

You could always locate a naked Sanyo ZTA 4.35v cell and something like a Littokala 100/202 and see if your light fires up?

Chris

 

[Katherine Alicia]

I`m trying to get to 6v or as close as possible with 2 cells, I`m not sure how I`d do the maths with 4.35 and another cell without mixing cell types. though 4.35 would light it up, it probably wouldn`t be a very nice beam.

 

[ChrisGarrett]

I`m trying to get to 6v or as close as possible with 2 cells, I`m not sure how I`d do the maths with 4.35 and another cell without mixing cell types. though 4.35 would light it up, it probably wouldn`t be a very nice beam.

You don't get there with dummy cells.

If the light fires up with a single 16650, even at 4.2v, then you have your answer. You might lose a bit of output, but you're no longer beholden to primaries.

3.2v RCR 16340s blow for longevity and anything you do try will be a small step up from Chinese dreck.

Chris

 

[Dave_H]

well I figured if I`m going to be doing this, then I may as well do it properly from the start, so I bought a charger for IFR cells as well. Worst comes to the worst I have several LED lights I can use them in so there`s nothing wasted.
The batts I bought are by Poover here: https://www.ebay.co.uk/itm/4-x-POOV...e=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649
I`v had batts by them before and they seem to be ok, and are still working fine a year later (even though I`d never heard of them before).

I`v read in a few places that if you leave these batts to rest for an hour or so, they do drop in voltage and tend to stabilise at about 3.35v (ish). so Now I`m wondering if i`ll have a few spare mm in the tube so that I can solder a couple of 1A diodes in parallel between 2 sheets of copper clad board and use that as an insert to drop the excess voltage, like: 3.35 x 2 = 6.7v - 0.7v = 6v.

Good that you got correct charger as regular 4.2v Li-ion charger on LiFePO4
would be not good as they top at 3.65v.

I got some LiFePO4 18650's used in garden lighting, and by chance in
second-hand store found a suitable charger with sliding contacts which take a
variety of sizes. Brand name is Rydelec. Slow charge, only 200mA though,
but most cylindrical cells have fairly low capacity anyway. Should be
other suitable chargers out there.

LiFePO4 has lower output voltage and capacity compared to "regular" Li-ion,
but it does have its advantages.

You could probably do the diode-drop thing but is it really necessary?
Will the difference between 6.6v and 6.0v likely have any consequences?

Dave

 

[Dave_H]

I only have one flashlight which runs from 2xCR123, nice but hardly
ever use it. Draws 400mA so run-time is short with primary cells.

Duracell Type 245(2CR5)camera battery ("6v")has inside two series cells
similar to CR123, but slightly smaller diameter. One which is years old still
measures 6.5v no-load (3.25v per cell). I'll likely disassemble them as
can't find any other use.

Coin cells such as CR2032 usually measure 3.3v new, when down at 3.0v
are starting to run out. Different Lithium primary chemistries are out there,
not all identical, some care in comparison required.

So voltage difference between primary Lithium CR123 and LiFePO4 does not seem
very much.


Dave

 

[xxo]

So voltage difference between primary Lithium CR123 and LiFePO4 does not seem
very much.

It's enough to blow incan bulbs.

 

[Katherine Alicia]

It's enough to blow incan bulbs.

Yup, I`v found this to be true also. Without that diode idea I wouldn`t risk it, However I have found that a 6V P60 dropin will run quite nicely with an 18650 cell and still be around 3000k.

 

[xxo]

You would probably need to drop it down to around 5V with the diode as that's about what a pair of CR123A's put out under load.

 

[Katherine Alicia]

well at the moment I`v kinda got them as backup cells because they work really well with a 7.4v dropin as well as in my E04 and OTR M3 Pro.

 

[Dave_H]

It's enough to blow incan bulbs.

I guess if you've tried it and that happens, who am I to argue...but
seems a bit strange unless the bulb is already overdriven at 6v as it is.

Just pointing out in the LFP123A datasheet, cell spends most of its discharge
in the 3.0v to 3.3v range.

Dave