Blame the Battery ....

[flatline]

When I do start using lithium-ions in my flashlight mods (and that may be relatively soon), I will only use cells from known, top tier cell manufacturers. Since cells from these manufacturers tend to be hard to come by, I will likely harvest cells from a power tool or laptop packs.

So does that mean that the only quality cells available are 18650s? Or do top tier cell manufacturers also make RCR123s?

The reason I'm asking is that I finally broke down and bought a 1xCR123 light (HDS high-CRI clicky) and 2 protected AW RCR123s. Is it your recommendation to just suck it up and use primary CR123 cells instead of rechargeable cells?

--flatline

 

[LEDAdd1ct]

For the HDS, you can purchase the 17670 tube, and use AW cells.

 

[Battery Guy]

Really depends on the cell itself

This is true, and the values that Lux gave should only be used as a general guide.

A long, long time ago (pre-2000), nearly all lithium-ion cells were made with essentially the same type of carbon for the negative electrode and LiCoO2 as the positive electrode. Today, there are different varieties of carbon and different metal oxides used, and these may shift the OCV at a given state of charge by 100 mV or more. There are even some commercially available lithium-ion cells that require charging to 4.3 V in order to be at 100% SOC.

So there is no OCV vs SOC curve that works for all lithium-ion cells. Even cells that use LiCoO2 can be quite different because of differences in the type of carbon used and the anode:cathode balance. And to make things even more complicated, as a lithium-ion cell ages, the anode:cathode balance shifts and the OCV vs SOC relationship will also change.

So the best thing to do is exactly what you did: make your own curves for your own cells. There is no substitute for that.

Just remember that the amount of time that you let the cell rest will also affect the results. You might be surprised in the difference if you repeated your test, but let the cells rest for 2 hours instead of 10 minutes.

Cheers,
BG

 

[flatline]

For the HDS, you can purchase the 17670 tube, and use AW cells.

If BatteryGuy doesn't trust the quality of AW cells, I don't see how his recommendation would be different between AW 17670 and AW RCR123 cells.

--flatline

 

[Fusion_m8]

Thanks Matt, a.k.a Battery Legend!

:thumbsup:

 

[Battery Guy]

If BatteryGuy doesn't trust the quality of AW cells, I don't see how his recommendation would be different between AW 17670 and AW RCR123 cells.

--flatline

I never said that I don't trust the quality of AW cells. In fact, my experience with AW leads me to believe that he is fully aware of the quality issues among various cell manufacturers and sources his product very carefully. I would say that AW is an exception to the rule.

Cheers,
BG

 

[Battery Guy]

So does that mean that the only quality cells available are 18650s? Or do top tier cell manufacturers also make RCR123s?

The larger, more established cell companies tend not to mess around with the goofy cell sizes that have low sales volumes. Therefore, you will usually only see 18650s, 26650s and 18500s available for purchase or harvesting from OEM battery packs.

Of all of the top tier manufacturers, Sanyo seems to have the largest variety of cell sizes, and they do make a RCR123 (also called an LC16340). You can find them forsale on Battery Universe here.

Cheers,
Battery Guy

 

[flatline]

I never said that I don't trust the quality of AW cells. In fact, my experience with AW leads me to believe that he is fully aware of the quality issues among various cell manufacturers and sources his product very carefully. I would say that AW is an exception to the rule.

Cheers,
BG

I apologize for putting words in your mouth. I didn't remember seeing AW in your list of trusted manufacturers earlier (either in this thread or another) and just assumed that you didn't trust AW.

But I'm glad to hear your opinion of AW since I've got 2 AW RCR123 (16350?) cells on their way for my new light.

--flatline

 

[jacknife]

Is there any Risk in testing Batteries, The ZTS tests under load, And I thought I read somewhere that you have to be careful testing with A multi tester, Is there risks testing batteries with any of these??

 

[45/70]

Just a few quick comments. Regarding why AW's cells are preferred by many on these forums over other Chinese cells, it has a lot to do with experience. Some of us that have used both AW's and the others over the past 5-6 years, like myself, have seen a marked difference. AW's cells nearly always have more consistency from cell to cell than the other brands, which is critical for series applications. This doesn't mean that you will never get a bad cell from AW, but I never have. This is something I can't say about cells from other distributors, such as xxxxxFire. Also, new cells from AW nearly always have better voltage retention than the others. This is a sign that the cells that AW provides are newer. Keep in mind that unlike NiCd/NiMH cells, all forms of Li-Ion cells start to degrade significantly, from the day they are manufactured, whether they are used or not.

Another factor that those fairly new to using Li-Ion cells may not be aware of, is that just because a new cell performs well, doesn't mean that it will perform as well 10, 20, or 50 cycles later. In my experience, AW's cells outperform other distributor's in the long run. They retain usable capacity for more cycles, and retain their consistancy from cell to cell, far better than any of the others. That doesn't mean that you won't come across a good sample from the other distributors once in a while, but this very inconsistency is a problem. You can never be as sure, what you're going to get.

As I have mentioned in other threads over the years, I don't know how it is, that AW manages to provide better cells, but I suspect that he has a close relationship with one or more of the 3(?) Chinese Li-Ion cell manufacturers. This possibly allows him to get "first pick" among the surplus cells manufacturer's offer. This no doubt would cost him more, and the additional cost would obviously have to be reflected in the price of his cells.

As for determining the estimated capacity of LiCo Li-Ion cells by measuring the OC voltage of the cell, the various charts/tables that are commonly used, were never intended to be an absolute means of estimating capacity. Also, years ago, when most all Li-Ion cells on these forums were LiCo, it was understood even then, that voltage readings below 3.80 Volts were not as accurate, due to differences in the actual composition of cells from different manufacturer's. Jason's findings seem to reflect this.

Dave

 

[LuxLuthor]

Guidelines are guidelines. In my posted guidelines which I got from Silverfox, there is the word "about" for each value. These are still better than having no guidelines, and however wonderfully accurate it may be to know the exact discharge graph for each cell you are using, re-evaluated at least once a year, and keeping track of all that as separate guides linked and meticulously scrutinized by people using a DMM to evaluate the cell state when removed from their flashlights is utterly preposterous. How many members using Lithium cells don't have a DMM, let alone an accurate and safe discharge testing setup?

In the interest of fairness and full disclosure, while I also regard AW's cells as a quality exception coming from years of experience and reading these and other forums, I did get a bad batch of 8 x 17670 cells several years ago. Upon arrival, they would not charge consistently, or properly on Pila IBC; did not reach full charge voltages, and in retrospect were likely dangerous. I posted about them in a thread somewhere...I think in a Fivemega mod where I was intending to use them.

I had a number of PM's with AW in addition to posting in that thread to find out what happened as the cause. That was back in the day that Lithium Ions were still being mailed easily all over the place, and he did promptly replace them while I returned them to Hong Kong. From memory, I think he finally traced this to either a bad batch of electrolye, or bubbles in the electrolyte, or some problem with the electrolyte layering. I have never forgotten since then that it is my responsibility to make sure to fully evaluate cells, even if from a trusted source.

 

[jasonck08]

The larger, more established cell companies tend not to mess around with the goofy cell sizes that have low sales volumes. Therefore, you will usually only see 18650s, 26650s and 18500s available for purchase or harvesting from OEM battery packs.

Of all of the top tier manufacturers, Sanyo seems to have the largest variety of cell sizes, and they do make a RCR123 (also called an LC16340). You can find them forsale on Battery Universe here.

Cheers,
Battery Guy

Hmmm... Are you sure these are legit Sanyo made cells? Maybe discontinued? It seems like Sanyo would list them on their site if they still made them or if they were legit: http://battery.sanyo.com/en/product/lithiumion_2.html

The only cells I've seen from Sanyo are 18xxx and 14xxx cells.

Capacity also seems a bit high. 800mAh from a 16340. Sanyo's 14500 (which IIRC is about 10-20% greater volume then a 16340) is rated @ 800mAh.

 

[Wiggle]

Why the recommendation to let cells sit before using? I can understand if it's multi-cell and you don't want one cell with a capacity different to sag more than the other but for average single cell use I don't see the risk. I top off the 14500 in my EDC light every day or two just cause I can and I always throw it right off the charger into my light.

 

[old4570]

Why the recommendation to let cells sit before using? I can understand if it's multi-cell and you don't want one cell with a capacity different to sag more than the other but for average single cell use I don't see the risk. I top off the 14500 in my EDC light every day or two just cause I can and I always throw it right off the charger into my light.

For single cell use it would not be important .. But it would give you some idea of the state of the cell .. As cells get older they degrade , a degraded cell fresh of the charger may show 4.2v , but after one hour it will show a more true capacity state . Was 10% per year mentioned some where ?

So if you have 1 year old cells , used or not , they may have degraded 10% , 2 year old cells 20% etc . Using old laptop cells of ?? state ..
For single cells use , not really an issue , but for multi cell , great care would be called for to sort out the batteries .

Most of the flame events used to be with CR123A primaries , folks simply did not check the state of the batteries when feeding the flashlight , and accidents happen , fresh cells with used cells , or cells with differing voltages being used , with a great enough variation

Now that multi cell 18650 lights are becoming ever more popular , we are starting to see flame events with the 18650 , and its a larger more powerful battery capable of doing more damage .

Some folks seem to think that because they use a protected battery they are safe , when nothing could be further from the truth . The PTC protects the battery from over discharge and charging , it does not protect you from stupid ! I dare say the PTC is giving some people a false sense of security , and may be contributing to unsafe practices .

 

[Battery Guy]

,,, I don't know how it is, that AW manages to provide better cells, but I suspect that he has a close relationship with one or more of the 3(?) Chinese Li-Ion cell manufacturers.

There are approximately 600 battery companies throughout China, and over 100 of those manufacturer lithium-ion cells. Most of the Chinese companies manufacturing lithium-ion are making pouch (aka "polymer") cells, but that still leaves a very large number making cylindrical cells like 18650.

I suspect that you are correct and that AW has relationships with several of the higher quality cell manufacturers in China, and works to insure that he is getting high quality product.

Cheers,
BG

 

[Battery Guy]

Hmmm... Are you sure these are legit Sanyo made cells? Maybe discontinued? It seems like Sanyo would list them on their site if they still made them or if they were legit: http://battery.sanyo.com/en/product/lithiumion_2.html

The only cells I've seen from Sanyo are 18xxx and 14xxx cells.

Capacity also seems a bit high. 800mAh from a 16340. Sanyo's 14500 (which IIRC is about 10-20% greater volume then a 16340) is rated @ 800mAh.

No idea if they are legit. I only know that Sanyo has a reasonably good variety of cylindrical cells sizes, and I found those cells when I did a quick Google search.

Nice link to Sanyo's battery site, and good point about the capacity. That is certainly sufficient information to cause one to have some legitimate suspicion of these cells.

Although, one thing about a cylindrical cell is that they all have a hollow region in the center of the cell where the electrodes were wound around a mandrel. The diameter of this hollow area is relatively the same for all cylindrical cell sizes. Therefore, the smaller the cell diameter, the less efficient the overall electrode packing in the cell is going to be. So it would not be too surprising to me if a 16 mm diameter cell has a 10-20% higher volumetric capacity compared to a 14 mm diameter cell from the same manufacturer.

Cheers,
BG

 

[Battery Guy]

Guidelines are guidelines. In my posted guidelines which I got from Silverfox, there is the word "about" for each value. These are still better than having no guidelines, and however wonderfully accurate it may be to know the exact discharge graph for each cell you are using, re-evaluated at least once a year, and keeping track of all that as separate guides linked and meticulously scrutinized by people using a DMM to evaluate the cell state when removed from their flashlights is utterly preposterous. How many members using Lithium cells don't have a DMM, let alone an accurate and safe discharge testing setup?

Hey Lux

When I read your post above, my first thought was "what kind of idiot would recommend such a thing?". Then I realized that you were talking about me!

In my previous post, I was not recommending that people make their own OCV vs SOC curves for their batteries. What I was trying to say is that if the guidelines that you posted are not sufficiently accurate for someone's needs, then that person should make his own curves...and that he would need to re-calibrate those curves after the battery ages.

It was not my intent to make that a general recommendation that all lithium-ion battery users follow. Although, rereading my own post I can see how it would be interpreted that way.

In the interest of fairness and full disclosure, while I also regard AW's cells as a quality exception coming from years of experience and reading these and other forums, I did get a bad batch of 8 x 17670 cells several years ago. Upon arrival, they would not charge consistently, or properly on Pila IBC; did not reach full charge voltages, and in retrospect were likely dangerous. I posted about them in a thread somewhere...I think in a Fivemega mod where I was intending to use them.

I had a number of PM's with AW in addition to posting in that thread to find out what happened as the cause. That was back in the day that Lithium Ions were still being mailed easily all over the place, and he did promptly replace them while I returned them to Hong Kong. From memory, I think he finally traced this to either a bad batch of electrolye, or bubbles in the electrolyte, or some problem with the electrolyte layering. I have never forgotten since then that it is my responsibility to make sure to fully evaluate cells, even if from a trusted source.

Also in the interest of full disclosure, I have only purchased one cell from AW, and that was a 14500 for my AA Ragone Plot testing. Therefore, I have no real experience with the quality of AW cells, good or bad. However, AW does appear to have established a very good reputation for himself as being able to supply high quality lithium-ion cells of various sizes. Based on some of his posts on CPF, AW appears to have an advanced knowledge of lithium-ion cell chemistry, construction and manufacturing.

Having one person who holds himself responsible for the quality of the product he sells, and is actually available via email or PM to answer questions, is worth a lot in my book.

Cheers,
BG

 

[45/70]

There are approximately 600 battery companies throughout China, and over 100 of those manufacturer lithium-ion cells.

Are we talking manufacturers, or distributors? From what I understand, there are only a few facilities that actually manufacture cylindrical Li-Ion cells in China. Li-Poly, I have no idea. Unless you consider taking a cell, shrink wrapping it, and optionally adding a protection circuit as "manufacturing", I didn't think there were that many actual manufacturers, of cylindrical cells anyway.

Attempting to find this kind of information about companies in China is quite difficult, as it is sparse and not readily available. I know, as I've looked into it a bit. Seeing as you work much closer to the industry than I do, you may very well be correct, but your estimate conflicts with my findings.

My apologies old, but this is sorta, kinda, remotely, indirectly related to your thread...... maybe.

Dave

 

[Battery Guy]

Are we talking manufacturers, or distributors? From what I understand, there are only a few facilities that actually manufacture cylindrical Li-Ion cells in China. Li-Poly, I have no idea. Unless you consider taking a cell, shrink wrapping it, and optionally adding a protection circuit as "manufacturing", I didn't think there were that many actual manufacturers, of cylindrical cells anyway.

There are somewhere between 50 and 75 cylindrical lithium-ion cell manufacturers in China. Very hard to ever know for sure as they are constantly changing hands, changing names, and new ones pop up all of the time.

One of the things to keep in mind is that all battery companies have "scrap". By "scrap", I mean fully manufactured cells that for some reason do not meet quality requirements. Most of the large battery companies actually dispose of their scrap cells. However, I have know for certain that many of the Chinese manufacturers will resell their scrap to the highest bidder. Most of these low quality, "scrap" cells end up in foreign markets, but a few turn up with private labels and are sold online. I have personally witnessed this practice numerous times, and it is the reason that I will not buy private label lithium-ion cells unless I am very confident of the distributor.

Cheers,
BG

 

[45/70]

There are somewhere between 50 and 75 cylindrical lithium-ion cell manufacturers in China. Very hard to ever know for sure as they are constantly changing hands, changing names, and new ones pop up all of the time.

After doing a bit of quick research, it looks like you're right, BG. While I didn't seem to find any list longer than 25-30 companies, if sorted and combined, there most likely are that many.

I did notice that at least a couple of these battery companies mentioned the use of Samsung, Panasonic, etc. cells, suggesting that they manufacture battery packs using cells sourced from actual Li-Ion cell manufacturers. Also, in my quick investigation it appeared that the majority of actual cell manufacturers do not produce cells smaller than 18650. This may have influenced my interpretation of the number of manufacturers that produce Li-Ion cells smaller than this, which I primarily use. Still, things are definitely changing, and my "guesstimate" was likely way off.

Dave