Recharging Energizer Ultimate Lithiums - Controlled experiments

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sxl168

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I was wondering if anyone with the right hardware has attempted to recharge the Energizer Ultimate Lithium cells. I was doing some reading and found some interesting information at: http://books.google.com/books?id=ZwD8uTpXet4C&pg=PA516&lpg=PA516&dq=nasa+lithium+iron+disulfide&source=bl&ots=l_lbu3l5fy&sig=3c2cBvA0ifgzQVzHhFdlok1tW44&hl=en&ei=az6qTvmYE6Hj0QHr3vnNDw&sa=X&oi=book_result&ct=result&resnum=3&ved=0CC0Q6AEwAjgK#v=onepage&q=nasa%20lithium%20iron%20disulfide&f=false

Page 516 and especially 517 show that a side chemical reaction takes place once the cell reaches 2.4 volts or so and needs to be avoided. After more Googling it appears that they use 2.25 volts as the cutoff voltage when charging the high temperature versions of this battery chemistry.

I ask because my brother gave me 2 Energizer Ultimate Lithium cells from his portable GPS unit that he had drained and I figured I would do some research and experimentation. I measured the voltage on each cell and one of them was completely dead at 1.5 volts open circuit and dropped to 0 under load. The other was at 1.65 volts yet and was still able to produce a bit of current yet. I grabbed the cells, the DMM, and an old but wonderful HP adjustable power supply outside on some brickwork in my back yard. I set up the power supply to limit to 2.25 volts and 20 mA of charge current and charged each cell individually. The mostly dead cell charged up mirroring the discharge curve and terminated after 6 days, which indicates that nearly the entire cell capacity went in. The completely discharged cell was charging up at 0.1 to 0.2 volts higher than the other one and it was fluctuating where it would increase and then decrease, increase, decrease in voltage over and over again as it charged. After 7 days, this cell too finally charged up, but I think its suffering from partial internal leakage as the OCV slowly decreases over time over several days from 2.25 volts to 2.0 volts. The first cell dropped to 2.14 volts and has held there now for 2 weeks with no decline. I have not yet attempted to discharge them yet to check capacity. They do power my Maglite AA however and charged right back up after this test. I will be doing discharge capacity tests soon when I get some more time.

Based on the tests I have done so far and my understanding of the chemistry, I'm guessing the completely discharged cell is probably toast as a full discharge will completely dissolve the lithium electrode and when recharging, it doesn't really have anything to plate out on, which would also help explain the higher charge voltage on that cell too and possibly some dendrite shorts popping through the separator. So if you want to recharge these cells, do not run them down 100%. I expected the cells to short out via dendrites when I attempted to charge them (which is why I did this outside) but I was shocked at how smoothly the one cell took charge. I'm sure they won't last through too many charge cycles however before the lithium electrode completely disintegrates and/or the cell shorts out.

I am checking to see if anyone else with the right gear has done anything similar with these cells and could compare notes.
 

Dr Jekell

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I am very very very surprised that you did not end up with a fireball spitting flaming battery internals all over the place or have a vent with flame when used in the light.

I am checking to see if anyone else with the right gear has done anything similar with these cells and could compare notes.

As far as I know no one else has done this as it is a very dangerous & unsafe thing to do.
 

sxl168

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I understand the safety precautions needed for these tests and is why I am doing these tests outside away from anything else. The flashlight test was just a 5 second test before I removed them from the light. Future large discharge tests will be done with power resistors. I will not be using these in any electronic gear unless tests prove they are safe. I have a lot more testing to do before I come to that conclusion. According to the Energizer datasheet, these cells have a pressure release vent, so I'm no so worried about the cells exploding. I still have taken precautions however just in case. Tests so far have failed to open the vent and also the tests that NASA has done to the cells in my original post leads me to believe that these cells are pretty safe if conditions are well controlled.

What I intend to do is buy a pack of cells, discharge-charge them in the 20%-100% of full charge window and see if they hold up. I am just doing some controlled experimentation on these cells similar to what NASA did, but with discharged cells and not doing overcharge tests. I have a BS in Physics and part of my training is how to carry out experiments such as these. I have worked with some dangerous things as part of the training (high powered lasers, very potent Cesium and Cobalt radioactive sources, high power microwave RF, and Carcinogenic chemicals), so I'm not new to safety requirements. I do a lot of research before I even attempt to do an experiment. I certainly don't want to give an impression to the general public that these cells are safe to charge up and I apologize if I have given that impression. These cells should be assumed to be hazardous if charged until proven otherwise. I am trying to work out what conditions these cells could be recharged if it's possible and safely.

I was just curious if anyone else has tried to charge them and what their results were so that I could decide what tests I should focus on.
 

RCM

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I don't think any of us are crazy enough to try and charge lithium primaries....I know I'm not! They can vent hydrofluoric acid I believe which is really scary stuff!
 

Mr Happy

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Safety considerations aside, I'm not sure why you didn't charge them to 1.8 V, the same voltage they have when new? Charging lithium cells to higher voltages than normal dramatically increase the risk of a chemical and thermal runaway reaction. If one were to contemplate recharging such a cell, a CC/CV algorithm would be indicated with a 1.8 V limit and a low maximum charge current.

You may or may not be aware that lithium metal chemistry was the first form of rechargeable lithium battery tried, but it was found to be too dangerous and was replaced by the familiar lithium ion chemistry. Even if you recharge a cell 99 times and it does not explode, that does not mean it will not explode on the 100th time.

I read the paper you linked to, and it does not suggest or advise charging to 2.25 V. The test in question was a deliberate overcharge scenario designed to see if the battery would fail. It would be crazy to interpret this as a charging recommendation.

As everyone else has said, there is no good outcome from such experiments. Once you have tried to charge a lithium primary cell it becomes a time bomb and you would not want to touch it.
 

tylernt

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As everyone else has said, there is no good outcome from such experiments.
I disagree. If the guy is testing in controlled conditions -- outside in a steel-lined concrete box, or whatever -- the only thing he's risking is wasting his money.

My take is, even rechargeable Li-ions go poof if charged improperly, yet those are "safe" when the correct charging regime is used. Perhaps there is a "safe" charging regime for lithium primaries out there too, just waiting to be discovered. If you never try, you never know. :)

That said, I agree such cells should be treated as time bombs until some VERY thorough testing has been done with repeatable results.
 

jtr1962

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One time I experimented with charging lithium primaries. These were 1/2 AA 3.6V cells (I think the chemistry was lithium thionyl chloride). With a slow charge I managed to revive some dead cells, but they seemed to quickly self-discharge. The mistake I made was treating the ones which refused to charge (i.e. stuck at close to 0 volts) the same as I treated NiCads in that state. I figured zapping them with high current pulses might get them to take a charge, same as this sometimes clears internal shorts on NiCads. Bad move. To make it worse, I was holding the cells while I was touching a wire to them. As I'm touching a wire to one cell, I notice a red glow right around the seal on the positive end. Time enough to drop the cell and close my eyes before it popped. There was a loud bang, like a firecracker, and my workroom filled with white smoke. For a minute I thought I was blind, at least until I went out of the room, washed my face, and opened my eyes. When the smoke cleared, there was some black stuff on the ceiling. I found the can of the cell intact, but completely empty. After that experience, I'm not even keen on using regular Li-ions. LiFePO4 cells are my preferred choice nowadays.
 

Mr Happy

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I disagree. If the guy is testing in controlled conditions -- outside in a steel-lined concrete box, or whatever -- the only thing he's risking is wasting his money.
Perhaps I should have said there is no useful outcome beyond some kind of morbid curiosity. There are no circumstances under which we can use a recharged lithium cell, and there is no way to dissect the cell and see what really might have happened inside it.
 

DFiorentino

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Should this thread be moved to the "Smoke and Fire" section now or later? Didn't we go through this some time before with the "nail tests"? As Mr Happy pointed out, what useful data could this possibly contribute to the community? Other than another possible Darwin Award recipient.

-DF
 

sxl168

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I chose 2.25 volts as I saw it referenced in a document I found once, but can't find again after doing another quick search, but this other document is the basis for my experiments: http://www.accessengineeringlibrary.com/mghpdf/0071449345_ar041.pdf

That document shows a charging voltage of 2.0 volts which is inline with what I saw when I charged up the 2 cells I have. Both cells spent a substantial amount of time in the 1.9-2.0 volt range. Once they hit 2.0, they rapidly climbed to 2.25 volts. At the slow charge I was doing, 2.0 volts is a good termination voltage, but the 2.25 might be needed later if/when I try higher currents. The cells do exhibit 0.1 to 0.2 volts of polarization compared to the discharge profile, so a charging voltage of greater than 1.8 volts is definitely required. I reference the NASA paper because it clearly showed that I needed to stay below ~2.4 volts for certain. The absolute termination voltage will only be determined via trial and error. What is known is that 1.8 is too low and 2.4 is too high.

I never attempted to charge a Li-SOCl cell and have no desire to as it's been shown to be a non-reversable reaction. I do intend to dissect the cells once they have lost the ability to hold charge. I have a Lexan sheet set up from previous experiments for this. I also have plenty of experience opening up all sorts of cells without destroying the contents from alkaline to NiCd to LiCoO2. As another point of reference, research universities do things like this all the time to learn all about the chemical reactions going on inside of batteries. I don't have all the expensive gear they have, which is why I carefully choose what to experiment on, but I do have labcoats, gloves, face shields and sheets of Lexan for protection. I just feel there are some knowledge gaps in this particular cell design that should be looked into.

I was just looking for some information that some of the knowledgable members of this forum might have. I definitely take offense to the Darwin award comment as I always take safety seriously when running experiments. I learned this long ago while at the University.
 

sunny_nites

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It's funny where people draw the line for what they feel is "safe" and "un-safe". No one seems concerned sitting on top of 20 gallons of gasoline in their car but mention "lithium" in the context of batteries and it's suddenly the end of days.

Personally, I'm very interested in what you find out, sxl168. I have yet to find a battery chemistry that gives the bang for the buck (pardon the pun :nana:) that lithium chemistry batteries provide. If members on this board are willing to push the limits, in a safe and professional way to provide data, go for it!
 
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SilverFox

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Hello Sxl168,

Welcome to CPF.

Keeping in mind that it can be dangerous to recharge primary cells, as long as you use proper safety measures you may be able to learn something.

You need to have a bench mark to compare your results to. I believe Energizer has some discharge curves to compare with, or you could pick up some new cells and produce your own discharge graphs. Next you can do your best to charge the cells, let them rest overnight, and then compare the discharge curves you get with those cells with new cells.

I have tried to charge a number of different chemistries, but haven't tried the Ultimate Lithium cells. Many times you can get the cell to take a surface charge, but during discharge you find that the capacity is very low, and the voltage under load drops like a rock, unless the current is kept to a very low value.

While charging and discharging, keep an eye on the cell temperature.

Tom
 

VegasF6

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Friend of mine recharged a Saft 14500. I don't think it was a controlled experiment, he just thought it was a rechargable cell. Dunno what charge current he used, I seem to remember it was no more than a 100 mA or so. Lucky.

I still have the cell laying around.
 

Mr Happy

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Friend of mine recharged a Saft 14500...

...I still have the cell laying around.
That was very lucky. Someone on this forum charged a Saft 14500 thinking it was a lithium ion cell and as I recall it exploded so violently it near destroyed his kitchen.
 

Therrin

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It's funny where people draw the line for what they feel is "safe" and "un-safe". No one seems concerned sitting on top of 20 gallons of gasoline in their car but mention "lithium" in the context of batteries and it's suddenly the end of days.

Let us know the next time that 20gal tank of gas just randomly explodes under normal use. Actually I'll be liberal, you can report in when this happens to either you or anyone else in the state you live in. =)
 

Mandog

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So has the OP suffered a fatal accident as a result of his experiments or what? Haven't heard back from him.
 

Wreck3r

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The members who do not have any constructive posts should not waste their time and the OPs by writing on this topic. It has been said that there are safety issues and no useful information can come out of it so stop repeating the same things.

The OP agrees with the safety issues and clearly wants to know if the data collected is useful or not. He has taken the necessary precautions to avoid injury to himself and to others. Why post time and time again that this is dangerous is beyond my comprehension.

Be constructive or don't post.
 

sunny_nites

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My point was that peoples conception of dangerous is relative and the OP shouldn't be beat up for his. I would not try this experiment myself, I don't have the safety equipment or experience. I would, however be interested in the results in an academic (ie. I would never try it myself) sort of way.

I drive cars and carry a lipo powered flashlight in my pocket everyday. I realize there are risks with both of these activities but the rewards outweigh those risks.

PS. I did a quick google search for vehicle fuel tank fires and found a few thousand entries.
 
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