# Investigating the Westinghouse 3.2 V AA LiFePO4 cells



## Mr Happy (Feb 27, 2010)

These are the latest generation of "green" cells being used for solar lighting applications and can be found, for example, in the solar lighting section of Wal-Mart.

I picked up a few of the 600 mAh AA/14500 variety to test and see what they can do.

An add replaced the OP's images. Bill

General Characteristics

They are identical in size to a regular AA cell, but lighter in weight. Each cell weighs 18 g, compared for example to 27 g for an Eneloop.

The nominal voltage is 3.2 V and this corresponds to the voltage seen under light load when freshly charged.

Charging

The cells are very unfussy about how they are charged. According to the LiFePO4 chemistry they should be charged with constant current up to 3.6 V and then constant voltage until the current tails off.

However, in practice these cells do not seem to mind being charged to higher voltages. If you charge them up to 4.0 V and remove them from the charger the extra voltage bleeds off until the voltage drops back down to 3.6 V or so.

This behavior seems to suggest the cells can be trickle charged with a low current such as would occur with the intended solar lighting applications, without needing complex charge control.

Discharging

Here, the cells seem to have the typical characteristics of the LiFePO4 chemistry. They have a relatively high internal resistance and do not do well with high discharge rates.

I measured the DC internal resistance at about 200 mΩ, a little less when freshly charged, a little more when discharged.

The following graph shows discharge tests through constant resistance loads. These correspond to approximate C rates of 0.5C, 1.0C and 2.25C. With true constant current discharge the voltage fall off at the end would be steeper. 

The measured capacity compares well to the claimed 600 mAh.

Ad removed

Conclusion

These cells are interesting, but not all that exciting. They are not A123 cells by any means. Possibly they would be a neat option for single AA LED lights where the head can take voltages up to 3.5 V.


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## ptolemy (Feb 27, 2010)

Good report. I guess if ultra portability is important, these wll work. But, at 600mah, versus their 3-4x denser AA cousins, the voltage really has to offer significant improvements for us to consider

Thanks!


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## alfreddajero (Feb 28, 2010)

I might have to check them out next time im there...if i may ask what charger did you use to charge them.......


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## Benson (Feb 28, 2010)

ptolemy said:


> Good report. I guess if ultra portability is important, these wll work. But, at 600mah, versus their 3-4x denser AA cousins, the voltage really has to offer significant improvements for us to consider


Since these, like all Li-ions, have negligible self-discharge, the most reasonable comparison to NiMH is LSD cells such as Eneloops.

Eneloop = 1.2V * 2Ah = 2.4Wh
Westinghouse = 3.2V * 0.6Ah = 1.9 Wh

So if the low voltage is fine, LSD NiMH are clearly 25% better. However, particularly in LED flashlights, two major benefits are realized with the higher voltage:
boost converters are generally more efficient as the supply voltage approaches the LED's Vf of 3.2-3.5V, so if the converter should have an efficiency of, say, 90% at 3.2V, and 72% at 1.2V, they'd come out even.
boost converters also frequently have difficulty giving high output from 1.2V, because the current required from the AA cell is about 3x the LED current. See, for example, the difference in turbo output on the Quark 123 vs. the Quark AA (same exact driver, with output specs given for different input voltages). So even if runtime is 20% less on low modes, the extra brightness on high may be worth it. The usual option here would be a LiCo (3.7V Li-ion) 14500, but as Mr. Happy mentioned, some lights (like the Fenix L1T) don't take well to over 3.5V.

I guess I'll have to look into getting some of these next time I'm at Walmart -- the ones I have ("Free Energy" brand) are only 400mAh, which is on the verge of uselessly low.


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## Mr Happy (Feb 28, 2010)

alfreddajero said:


> if i may ask what charger did you use to charge them.......


I don't have a proper charger, so I just cobbled something together with Eneloops, like this:

Ad replaced OP's images

Charge for about three hours or until the voltages equalize. As far as I can tell you don't have to be precious about the charging voltage on these things unlike lithium cobalt cells.

If I were going to use these cells a lot I would come up with a more permanent charging solution.


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## alfreddajero (Feb 28, 2010)

I wonder if these cells would do well in a Nitecore D10 just for use around the house and for backup.


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## supergravy (Feb 28, 2010)

alfreddajero said:


> I wonder if these cells would do well in a Nitecore D10 just for use around the house and for backup.



I use similar cells to these (battery station 14505 lifepo4) in a lot of my AA flashlights. With the Nitecore D10 they don't bring much to the table as brightness is about the same as Eneloop or any other battery chemistry. The regulation of the D10 keeps things in check and run time doesn't seem any better either. 

Where I really like these batteries is in my fenix and quark flashlights. Both reward you with much higher output on lifepo4 then you would get with nimh or alkaline. And you don't end up losing modes in the fenix, which is a problem with 3.7v 14500's. Run time is mediocre at best though.

I have checked a couple of walmarts looking for the westinghouse batteries but so far no luck. I don't think these are an item that they regularly stock so prepare your expectations accordingly.


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## alfreddajero (Feb 28, 2010)

Okay thanks for the update, i guess in my case it will not be worth getting them.


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## Mr Happy (Feb 28, 2010)

supergravy said:


> I have checked a couple of walmarts looking for the westinghouse batteries but so far no luck. I don't think these are an item that they regularly stock so prepare your expectations accordingly.


If found, they would be in the garden section with the solar lighting.


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## jasonck08 (Feb 28, 2010)

cant believe no one has asked yet... how much do they cost?


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## Mr Happy (Feb 28, 2010)

jasonck08 said:


> how much do they cost?


$10/4


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## jasonck08 (Feb 28, 2010)

Not too bad... I believe 600mAH is very good for LiFePO4 cells.

On DX they have some 14500 350mAH LiFePO4 cells, these are much higher capacity and are about the same price per unit.

Have you attempted discharging them at 2C? What are the results?


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## Mr Happy (Feb 28, 2010)

jasonck08 said:


> Have you attempted discharging them at 2C? What are the results?


I have not done a 2C discharge yet but may do one later.


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## alfreddajero (Feb 28, 2010)

If im able to find the cells then it might just be worth getting a pack for the hell of it. As long as the light comes on then to me thats what really matters right.


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## Mr Happy (Feb 28, 2010)

jasonck08 said:


> Have you attempted discharging them at 2C? What are the results?


I have added a high load discharge test to the graph.


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## jasonck08 (Feb 28, 2010)

Mr Happy said:


> I have added a high load discharge test to the graph.


 
Thank you!  Did the cell get warm at all during the test? Do you think it can go any higher... 3C or 4C? Thanks for the tests. It's very valuable information.

Regular LiCo cells usually have a max recommended max discharge of 2C, but I was under the impression that LiFePO4's can usually go a lot higher.


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## Mr Happy (Feb 28, 2010)

jasonck08 said:


> Thank you!  Did the cell get warm at all during the test? Do you think it can go any higher... 3C or 4C? Thanks for the tests. It's very valuable information.
> 
> Regular LiCo cells usually have a max recommended max discharge of 2C, but I was under the impression that LiFePO4's can usually go a lot higher.


No the cell did not get more than very slightly warm.

Remember that these are regular old fashioned LiFePO4 cells, not the new breed of specially modified ones such as nano-phosphate or A123 Systems cells. Regular LiFePO4 chemistry has limited discharge rates due to the high internal resistance. You can see that by the way the voltage drops quite significantly at 2C in my graph.


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## jasonck08 (Feb 28, 2010)

Just got back from WM. Had to pick up a few things. I found these for sale, so I also picked up a pack to test ou.

They had 14500's and also 18500's. The funny thing about the 18500's is they were also rated at 600mAH, despite there 40% larger size.

I suspect that the 18500's may be under rated. I don't have anything that uses 18500's, otherwise I would have grabbed some for testing.

Mr Happy did you see any 18500's at your WM?


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## alfreddajero (Feb 28, 2010)

Once you get them charged up can you post what lights your going to use them in and how well they did, and what charger you used.


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## Mr Happy (Feb 28, 2010)

jasonck08 said:


> Mr Happy did you see any 18500's at your WM?


Yes, but I thought, "What's the point of making a bigger battery with the same capacity as a smaller battery?" So I didn't get any.


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## 45/70 (Feb 28, 2010)

:sigh:


Mr Happy said:


> Yes, but I thought, "What's the point of making a bigger battery with the same capacity as a smaller battery?" So I didn't get any.



I haven't checked out Wallyworld for these yet, as I don't really have any need for 3.2 Volt 14500 LiFe cells. If they had 18650 size that were ~1200mAh, I'd be interested. From what I gathered from the other thread, the 18650's they do have, are likely just 14500's in an 18650 package so they'll "fit" the intended application. 

*EDIT:* My mistake, they're 18500's, not 18650's. All the worse. :sigh:

Dave


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## Benson (Feb 28, 2010)

It's just possible that the 18500s, even if they have no more capacity, may have lower internal resistance as an entirely unintended side effect of making a larger cell with the same capacity, allowing significantly faster discharges. In this case, they'd be quite handy for burning off 6V incans in 3-cell bodies... great for anyone with a sizable investment but wanting to switch to guilt-free lumens.


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## Mr Happy (Feb 28, 2010)

Benson said:


> It's just possible that the 18500s, even if they have no more capacity, may have lower internal resistance as an entirely unintended side effect of making a larger cell with the same capacity, allowing significantly faster discharges.


I wondered about that, but I couldn't think of any justification for faster discharges in solar lighting applications where there is an inherently low rate discharge requirement. Therefore I didn't buy any to find out.


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## Mr Happy (Mar 1, 2010)

Benson said:


> the ones I have ("Free Energy" brand) are only 400mAh, which is on the verge of uselessly low.


Here is a comparison of the Energy Free cell compared to the Westinghouse cell at the same 10 Ω load:

Ad replaced OP's images...Bill

The Energy Free cell does not compare very well, does it?


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## Benson (Mar 1, 2010)

Oops, misremembered the name. But after all, they are almost "energy free", aren't they?


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## alfreddajero (Mar 1, 2010)

Well stopped by WM tonight and did buy a pack.......for some reason the cell works well in all my other single celled lights except my D10, in which it acts just like a nimh or alkie. Not bad at all for 10bones.


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## jasonck08 (Mar 1, 2010)

One of my cells out of the pack arrived @ 0.8v. So I'll probably bring it back to walmart for a refund. I'll test them in my other lights first. So far in one of my 14500/AA XP-G lights, it worked very well.


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## Mr Happy (Mar 1, 2010)

jasonck08 said:


> One of my cells out of the pack arrived @ 0.8v. So I'll probably bring it back to walmart for a refund.


That's interesting. I also had one cell arrive at 0.6 V while all the others were about 3.3 V. I took the package back and exchanged it for another one.

Seems that quality control is not very good on these cells.


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## Benson (Mar 1, 2010)

Well, I hit Walmart today and grabbed some of each; I'm quite sure the 18500s aren't just the AAs with a sleeve, as they're button-top rather than the AA nipple-top. This makes me cautiously optimistic about lower resistance, by virtue of greater area.

I will be testing them and posting some results as soon as I get a chance... stay tuned.


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## jasonck08 (Mar 2, 2010)

Doing a discharge test right now on one of these cells. I accidently charged it up to about 4v (because I don't have a proper charger for these). After 5 minutes of sitting there, the battery bled off the access voltage and now its sitting at ~3.5v.


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## alfreddajero (Mar 2, 2010)

Mine came off the charger at 3.5 volts as well.......what charger did you use. Did your cells get warm.


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## jasonck08 (Mar 2, 2010)

I'm just using a single bay 18650 Chinese generic charger designed for LiCo cells, with a spacer. It charges @ about 500-600mAH so about 1C for these batteries... The batteries only got slightly warm, but I think all the heat was actually from the charger itself as it has the power transformer built into the base unit.

EDIT: My first test cell yielded 562mAH @ .5A draw, or almost 1C. Not bad at all. Would probably be around 580-590 with a lower .2C draw.


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## alfreddajero (Mar 2, 2010)

Mine was warm, dont know if it was due to the charger or the cells......im using a new gen wf139 that AW sells. Instead of using an AW 14500 in my Riverrock 1watt i just use one of these now, brought new life to the light. Brighter and the flashlight doesnt get as hot, just warm now due to the voltage. Thanks Mr. Happy for spotting these and posting the thread.


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## 45/70 (Mar 2, 2010)

jasonck08 said:


> Doing a discharge test right now on one of these cells. I accidently charged it up to about 4v (because I don't have a proper charger for these). After 5 minutes of sitting there, the battery bled off the access voltage and now its sitting at ~3.5v.




Most LiFePO4 cells are very forgiving when overcharged. Yes, it is possible to charge them up with a LiCo/LiMn charger, but it is not recommended to do so.

The problem is, charging them with a 4.2 Volt charger will drastically reduce their cycle life. For example, you may only get 100 charges instead of 2000. This of course all depends on the particular cell's formula, but charging LiFePO4 cells with a charging voltage of greater than 3.6-3.8 Volts, will reduce the cycle life of the cell.

Dave


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## alfreddajero (Mar 2, 2010)

Thanks for letting me know that as i had no idea. Oh well guess ill stop using them then........back to AW's.


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## Mr Happy (Mar 2, 2010)

alfreddajero said:


> Instead of using an AW 14500 in my Riverrock 1watt i just use one of these now, brought new life to the light. Brighter and the flashlight doesnt get as hot, just warm now due to the voltage.


The River Rock 1 W is a single AA light, is it not? I didn't know it was safe to over volt it like that? I suspect with a LiCo cell you are pushing the boost circuit into direct drive and that is why the light gets so hot. I doubt it is good for it. My light does not get warm at all with a regular AA cell.


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## alfreddajero (Mar 2, 2010)

It is........but it seems so anemic with nimh or alkies, I have had the light for years now so i dont imagine that the led or circuit will last when using a lithium cell. Are there new RR's with upgraded emitters, its been awhile since i went to Target.


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## 45/70 (Mar 2, 2010)

alfreddajero said:


> Thanks for letting me know that as i had no idea. Oh well guess ill stop using them then........back to AW's.



Hey, if you have some, you may as well use them.  I just wanted to point out the downside to using a 4.2 Volt charger. At least the cells won't go  like LiCo's might, if they were charged at a higher voltage!

Dave


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## alfreddajero (Mar 2, 2010)

Yes of course your right...why have something that im not going to use clutter my drawer. Well i do get a green light when the charge is complete.


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## 45/70 (Mar 2, 2010)

alfreddajero said:


> Yes of course your right...why have something that im not going to use clutter my drawer. Well i do get a green light when the charge is complete.



Keep in mind that "geen light" is indicating ~4.20 Volts, as opposed to the proper ~3.6 volts appropriate for LiFePO4. 

Carry on!

Dave


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## alfreddajero (Mar 2, 2010)

Yes your right.......now i know why it took me a while to go to this side of batts when it came to lights. So much to read and so much to learn. Thanks for your input yet again.


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## Mr Happy (Mar 2, 2010)

OK, I did a quick comparison test with a light meter:

```
Light                                   Relative light output
----------------------------------      ---------------------
River Rock 1 W (Energizer lithium)         1.0
River Rock 1 W (LiFePO4)                   2.5
Coleman MAX 2AA 115                        3.75
```
Yes, the River Rock certainly gets way brighter with the 3 V cell. I guess that shows it is not regulated. I really don't know if I would want to run it that bright for a long time. :thinking:


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## alfreddajero (Mar 2, 2010)

Its mainly my indoor light.....i have brighter lights that i use for outdoors. The longest i have had it on using an AW cell is about 15minutes walking the dog up and down the street.


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## jasonck08 (Mar 2, 2010)

I think I have a 3V charger somewhere thats designed more for LifePo4's. Think it terminates the charge at around 3.6v.

Is that what these are suppose to be charged to, or is it more around 3.4-3.5?


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## GarageBoy (Mar 2, 2010)

what is their intended purpose?


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## jasonck08 (Mar 2, 2010)

GarageBoy said:


> what is their intended purpose?


 
Out door solar lamps.


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## Benson (Mar 6, 2010)

Benson said:


> Well, I hit Walmart today and grabbed some of each; I'm quite sure the 18500s aren't just the AAs with a sleeve, as they're button-top rather than the AA nipple-top. This makes me cautiously optimistic about lower resistance, by virtue of greater area.
> 
> I will be testing them and posting some results as soon as I get a chance... stay tuned.


And the results are in -- about 150mOhm for both sizes, with both (in a fully charged 4s pack) driving a CSM-360 to 1.68A

Still, that puts either size better than the "Free energy" ones at 200mOhm, better than a (somewhat used) CR123 I clocked at 400mOhm, and better than a random ICR14500 (freshly charged, but almost a year old, with light use) also right about 400mOhm.

But since the 18500 and 14500 are the same resistance, and (I presume) the same capacity, I'm not sure why they even produce the 18500s and whatever solar devices take them... I'm sure not buying any more.


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## alfreddajero (Mar 6, 2010)

Thanks for the update......


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## lctorana (Sep 7, 2010)

What would the target market be for the 18500 version to the general populace?

Is this size also used insome solar garden lights?


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## Mr Happy (Sep 7, 2010)

lctorana said:


> What would the target market be for the 18500 version to the general populace?
> 
> Is this size also used insome solar garden lights?


These Westinghouse cells in both AA and 18500 sizes are sold as replacements for solar garden lights. I have no idea why they would go to the trouble of producing the same capacity cell in two different sizes, unless, perhaps, there were some early versions of the 18500 with more capacity than the AA size and some lights took advantage of this. Certainly the "Energy Free" AA size cell that was on the market last year was no match for this year's Westinghouse AA cell, having only half the capacity.


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## CarpentryHero (Dec 22, 2012)

I found Westinghouse 18650 lifepo4 1200mah at Canadiantire. There where Noma grey ones too. I posted where in the good deals (canada) in cpfmp


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## mk313 (Oct 28, 2013)

Hey guys, sorry to resurrect an older thread, but I literally know nothing about batteries & this site came up when I googled the batteries I found. I am looking for a charger that I can use to recharge the Westinghouse batteries that look like AA batteries. They are the ones originally referenced on this thread (the side of the battery reads (600 mAh rechargeable 3.2 V, AA LiFe PO4).

To make a long story short my wife bought some "ghosts' that hang off the side of the house. They came with solar powered LED lighting, but the solar chargers don't work (or else we don't get enough light to charge them). I took apart the barging assembly & they contain these batteries. I bought a second pack to get us through this Halloween, but I will need to charge them at some point. I have no idea what kind of charger would charge these batteries. I tried googling it, but there are so many different numbers on the chargers that I'm not sure what will work & what won't. I have a charger that I use at home to charge my envelops, but I'm assuming that won't work with these batteries due to the different V & mAh numbers.

Can anyone recommend a charger that will work with these batteries?

Thanks in advance,


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## Pluot (Aug 25, 2015)

Sorry to post to an old thread, but I finally joined today, after lurking occasionally for over a year. 

First, a request... On the first page of this thread are a bunch of posts that claim to show test results on these batteries. Unfortunately, instead of data, I see an ad for a free ITunes gift card, with mention of a Rain App. It looks like these ads replace the data posted for each test (4 times on the first page). I guessed that the ads will cover attachment files for non-members, which finally prompted me to join (as I should have before). The ads are still there when I open the page as a member. How do I view the attachments in this thread?

I found these 3.2V Wally-Westinghouse batteries and bought a set long before I had a flashlight I knew would fit. I bought a Chinese Ultrafire Cree flashlight about 18 months ago, and it works well in that. I have been charging, for now, with a Tenergy TN270 Li-ion charger, for 14500, 18500 & 18650, rated for 4.2V out at 500mA x2. It is easy to open the charger, and I suspect it might not be difficult to add a switch to stop the constant current charging at 3.7V, and switch to 3.7V constant voltage. I didn't modify it yet, but the original 4 Westinghouse cells have worked very well so far. 

That's unlike the Ultrafire 14450s I bought with the flashlight. They were grey, and unprotected. One shorted within about a month. Since I was using a dual Chinese 14450 charger, charging 2 cells, it overheated the second cell within about 45 seconds before I cut it off. I found that the 2 cells were physically in parellel, rather than isolated, creating this hazard. A similar 18650 charger also had the 2 cells in parallel. I will NEVER use such a charger again for more than one cell at a time.


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## Bullzeyebill (Aug 25, 2015)

Pluot said:


> First, a request... On the first page of this thread are a bunch of posts that claim to show test results on these batteries. Unfortunately, instead of data, I see an ad for a free ITunes gift card, with mention of a Rain App. It looks like these ads replace the data posted for each test (4 times on the first page). I guessed that the ads will cover attachment files for non-members, which finally prompted me to join (as I should have before). The ads are still there when I open the page as a member. How do I view the attachments in this thread?



The images (data) are gone, and can not be retrieved. I removed the ads.

Bill


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## Pluot (Aug 26, 2015)

Bill,
Tnx for the answer. Too bad the images are gone, as I am using those batteries, and I wanted to see
the curves. They are working well, in my pocket, and rarely run down when I rotate weekly and
recharge the current one. After 20 months use like this, they are much better than the Chinese
14500's I also bought. I bought 2 grey UltraFire LC14500 900mAh 3.6V Li-ion with PCB (but no PCB!),
and 2 Blue 3.7V 1200mAh 3,7V Li-ion, in January and June, 2014. As an example, I just made a quick
comparison of the 3 cells, using one sample of each, topped off in the Tenergy TN270 charger. To
estimate mAh and Wh, I used starting current and estimated voltage, which will remain fairly constant
during discharge. This is at least a 1C load, so I expect 10 to 20% mAh reduction. 


Each battery heated the flashlight too much, so was turned off for 10 minutes after 15 minutes
operation. 


Westinghouse 14500 3.2V 600mAh LiFePO4: 4.18V-oc 0.63A 38 min until discharged, to 1.8V & .22A. .63A x 38min = 399mAh, 1.28Wh 


Grey UltraFire 14500 3.6V 900mAh Li-ion: 4.21V-oc 0.87A 22 minutes to 2.58V & .22A. .87A x 22min = 319mAh, 1.18Wh 

Blue 14500 3.7V "1200mAh" Li-ion: 4.11V-oc 0.86A 30 min 2.35V .34A final current .86A x 30min = 430mAh, 1.59Wh 

The Westinghouse was the star here, still delivering 400mAh after 20 months of overcharging. The blue
1200mAh was almost as good, with 430mAh, compared to its "spec" of 1200mAh.
The Grey UltraFire was the worst, delivering 319mAh, compared to a 900mAh spec. 


I would rather have the longer life and accept the lower output of the Westinghouse 3.2V, along with
the safety of LiFePO4 in my pocket! However, I will try to add a switch to that charger to charge 3.2V
wtih a 3.7V limit, and will report the result on CPF.


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