# Lithium Ion Batteries still not quite perfected? (NT)



## Steve Stockham (Jan 2, 2008)

I know that LiON battery technology has come a long way in the past ten years but I was just reminded that these things aren't foolproof! My son has one of these remote control helicopters (the starter one that uses a gyro rather than a tail roter) which has a dinky little Lithium-Ion battery that plugs into a battery operated charger to recharge. It had been recharged about 40 or 50 times (only about a week and a half considering how much the kids play with it) when it got hot during a recharge. I was gone and my wife pulled it off of the charger. When I got home I saw it sitting beside the charger and plugged it in. As I was doing that, Patsy told me what had happened. I immediately disconnected it from the charger and felt the battery. It was getting _hot!_ As I went to put it down it started to swell and it split with a hiss!! (Talk about dropping the thing like a hot potato! I don't remember a time that I moved faster!!) It had been attached to the charger for less than 15 seconds and it blew out the sides! Fortunately, it was a 1.5v battery and the size of an old Trident gum stick but what if it had been 19.6v and what if we hadn't been around?? I'm a committed r/c battery user but this reminds me not to take these new technologies for granted! Having a battery blow up in the palm of your hand tends to do that to you!


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## Del Tapparo (Jan 4, 2008)

Sounds exactly like what a Li-Po (Lithium Polymer) battery does when overcharged. I think the Li-Pos are still a little scary when not used under the proper conditions.


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## Stan Cedarleaf (Jan 2, 2008)

Yes, Steve. I would agree with Del. The Li-po's are touchy and when overcharged, they let out all kinds of very hot flame and smoke. The airplane folks use them because of the light weight to high power ratio. Big bang for the light weight and fast charge capabilities but only with recommended chargers and a watchful eye. (pun)

It could happen the same way with Li-ions but for the most part, I hope we use chargers that are matched to the battery.

So sorry to hear that Patsy and Eric had to experience that stress.


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## dieseldude (Apr 21, 2009)

I've had problems with a Li-Po battery as well. We have a portable DVD player that we use on plane trips (not really train related). The Li-Po battery that came with the unit worked great for about 3 months (just long enough for the warranty to run out!!) Then, it stopped charging fully. It only holds about 20 minutes worth of charge. Not many flights that last 20 minutes!! We ended up having to purchase a second battery. It works better, but only time will tell. I don't suppose any of you Battery Gurus know of a way to fix this problem.


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## Michael Glavin (Jan 2, 2009)

Yeap, its most likely a Li-Po @ 3.7V probably about 150mAh. Li-Po's are typically not provided with any cell protection circuitry or mechanical pressure relief vents typical of Li-Ion offerings. Thus the recmonedentaion for fire-safe charging enclosures. Li-Po like Li-Ion have the potential for some serious failure modes!!!! 

A quality charger and batteries goes a long way for user protection and product life expectancy. 

Michael


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## Dennis Paulson (Jan 2, 2008)

I have and use around 40 LiPo batteries in many sizes , some are 5 years old , with all of my various rc planes and helis they work great . 
BUT just as with my black powder firearms , well all firearms , I take care in the use , storage and reloading part of the hobbies . 
You have to take care and follow guidelines , and be right there with a chargeing LiPo battery , and store it correctly / safely . 
The great advantages of LiPos out weigh the risk involved with their use . 

YOUR mileage may vary , and don't try this at home , applies here .


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## Torby (Jan 2, 2008)

Yikes! 

Then you have to go change your pants


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## Ralph Berg (Jun 2, 2009)

Any battery can "blow". I've had it happen with car batteries and even had a standard AAA cell blow up in my optical mouse while I was using it.
Ralph


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## George Schreyer (Jan 16, 2009)

Any battery can internally fault and self heat.... a lot. But Lithium based batteries can do so with more violence due the reactive nature of Lithium itself. I don't expect that this issue will ever be permanently fixed until some other material is used. Unfortunately, the chemical properties of Lithium that make it work well in a battery are the same properties that makes it burn so well.


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## Steve Stockham (Jan 2, 2008)

The battery in question was used in a correct manner. It was properly charged in the charger that it came with and then fully discharged by operating the helicopter until the blinking light warned that it was time to set the helicopter down and recharge the battery. Oh, it turns out that it was indeed a Li-Po battery and not a LiON. It was just weird that it blew out it's sides in my hand!!


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## Dennis Paulson (Jan 2, 2008)

Steve what brand of Lipo battery was it ? For my own protection I would like to know please , thanks 
Dennis


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## Greg Elmassian (Jan 3, 2008)

No name Chinese. 

Something is not being emphasized here... the quality of the battery. 

Cheap stuff is not as good as good stuff. Batteries, chargers, etc. 

Greg


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## Steve Stockham (Jan 2, 2008)

Okay Dennis,
The battery has a label that says E-flite­ and below it 3.7V 120mAh (.5Wh) 14C Lithium Polymer Battery and in very small print: EFLB1201S 
It is copyrighted 2010 Horizon Hobby Inc.


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## Michael Glavin (Jan 2, 2009)

Steve 

I'd return the product to your local hobby shop and or contact Horizon Hobbies. Horizon is a great company and will more likely than not exchange the battery for you. I have dealt with Horizon for many years personally and am aware of there interest in protection of their product lines and namesake. I've seen them bend over to make customers happy many-many times. Been playing with RC airplanes and Helis for years....... Used to travel the country with my son attending events and contests as fully sponsored Flight Team and regularly had interaction with Horizon staff and factory Pilots, albeit they were the competition. 

Michael Glavin


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## Steve Stockham (Jan 2, 2008)

It's a good idea but I disposed of the battery almost as soon as I was sure it wasn't going to catch fire! It's okay though! I had a second one and I do understand that this can happen...


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## Michael Glavin (Jan 2, 2009)

Proper disposal of Lithium batteries is a MUST in today’s world of GREEN ecology, save the trees and the safety of those that may be exposed to same in the disposal process.

FWIW: Recommended Lithium disposal practice is copied below, the thing to remember is this chemistry can be volatile and judicious care is paramount…

1) Remove the battery from the device it is stored in. Examine the battery. If the battery or battery pack appears swollen, torn or dented skip to step 5. It is not safe to complete the below steps with a damaged battery.

2) Fill a bucket with sand. Place the lithium polymer battery in the bucket of sand. Alternatively, a fireproof container can be used.


3) Plug the connector on the battery into the connecter of a lithium polymer battery discharger. Set the discharger to the lowest value.

4) Allow the battery to discharge until the discharger displays the voltage has reached 1.0 volt per cell or lower. This process may take up to 24 hours. 
gently pull on the connector to remove the battery from the discharger.

5) Fill a bucket with three gallons of cold water. Add 1/2 cup of salt. Swirl the bucket until the salt dissolves in the water.

6) Place the battery in the salt water. Ensure the battery is fully submerged. Allow the battery to soak in the water for two weeks.

7) Remove the battery. If desired, the battery can be wrapped in old newspaper or placed in a plastic bag to keep the battery from dripping all over. It is 
now safe to place the battery in the trash.
Michael Glavin


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## Del Tapparo (Jan 4, 2008)

That may be the right thing to do. But it ain't go'in happen at my house.


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## Greg Elmassian (Jan 3, 2008)

Man, I have more fun... I put the battery out in an open area and charge the bejezus out of it... it catches fire, burns up and then I'm good to go for throwing what, if anything is left. 

Ya gotta learn to live a little ha ha! 

Greg


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## TonyWalsham (Jan 2, 2008)

All the more reason to beware of *Li-Po* batteries. 
Don't for one minute expect to be able to charge them on board the loco. 
They *MUST* be removed and balanced when charging. 
Just another inconvenience.


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## Michael Glavin (Jan 2, 2009)

Tony, 

On the other hand, with the balance port chargers and Li-Po's it doesn’t get much better with regard to monitoring the battery and or specifically the individual cells. This is not plausible with Li-Ions batteries currently offered by any OEM's to the best of my knowledge. 

What I’m alluding to is the ability of the charger to individually monitor each cell in the battery while charging and or discharging. These chargers are intelligent and make decision based on programmed algorithms’ and in some cases user input. If a specific cell is lagging in the charge mode i.e., not reporting like voltages of the other cells in play an error alert is annunciated, intelligent algorithms step in and or user interface is required. When balancing or discharging the charger individually matches each cell down to the tenth of a volt. If a Li-Ion batteries cells get too far out of balance the battery is unusable… This is do to the safety circuits openig the circuit based on its deferential voltage specification, only way around it is to bring the aforementioned cell back to minimum voltage specification which is not plausible without cutting up the pack and giving the cell in question some TLC.

In the scheme of things the balance chargers offer a MUCH more sophisticated operation than a Li-Ion charge regimen which solely relies on the safety circuit to simply open the circuit due to over/under voltage circumstance. Li-Ion chargers are really nothing more than filtered/regulated power supply with a fixed voltage output for the cell count in play, basically their dumb. No cell balancing and or cell monitoring is relayed to the charger and or notable/viewable by the user. A balance charger can display each individual cells activity throughout the regimen in play. 

I feel the balance charger/battery approach is safer than the atypical Li-Ion charger. That said I have several Li-Ion batteries wired with/for balance charging pigtails same as Li-Po’s, works great for me. And I live on the edge somewhat as the two LGB Moguls I rigged each carry six Li-Ion 18650 cells in series offering 22.2V sans the on-battery safety devices, the cells are permanently mounted in the Vandy tenders and are NOT removed for charging, albeit they are not charged while unattended. Unless the charger goes south its highly unlikely thermal runaway can rear its ugly persona... Cause and effect is similar to the onboard safety devices of most Li-Ion batteries but with greater monitoring and control IMO. 

That said I totally agree Lithium cell technology can be and is dangerous with the uniformed and informed alike. Do NOT become complacent with your batteries. Safety is paramount, a fire extinguisher nearby, an adequate charging enclosure of some sort has merit and perhaps charging on the kitchen table is a bad idea; an open area is best IMO. 

Since I went this far preaching the benefit of balancing chargers, Lithium cells wired/charged in Parallel ONLY, inherently balance themselves. Confused? 

Michael


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## Steve Stockham (Jan 2, 2008)

Can anyone say, "NiMH?"


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## TonyWalsham (Jan 2, 2008)

If they didn't self discharge quickly they would probably be OK.


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## TonyWalsham (Jan 2, 2008)

Michael. 
I don't disagree with anything you say. 

The problem is, and as a supplier of batteries and R/C equipment, I can guarantee you this, the vast majority of battery R/Cer's want to charge the loco batteries on board. That is a bit hard to do with balancing chargers. 
Removing the batteries for charging is not an option for them.


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## Michael Glavin (Jan 2, 2009)

Tony, 

I feel you.... But I'll squirt some pictures of the Vandy tender I alluded to above and share them. Its easy; one 2.0mm charge jack and one balance port (in my case its a seven pin conductor). I made mine, but you can purchase balance port plugs, sockets, extension cables and the like. 

Michael


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## steam5 (Jun 22, 2008)

Michael could you share your pictures 

Thanks 
Alan


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## Greg Elmassian (Jan 3, 2008)

batteries in parallel don't balance themselves, in fact it's worse... 

In series, at least you know the charging current is the same for all cells... so, unless one cell is shorted you are ok. 

In parallel, the cells with the lower resistance get more current. 

That's worse, since there's always a small difference between cells. 

Greg


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## Michael Glavin (Jan 2, 2009)

Posted By Greg Elmassian on 04 Feb 2011 01:43 AM 
batteries in parallel don't balance themselves, in fact it's worse... 

In series, at least you know the charging current is the same for all cells... so, unless one cell is shorted you are ok. 

In parallel, the cells with the lower resistance get more current. 

That's worse, since there's always a small difference between cells. 

Greg 

Greg, Give this some more thought.... Michael


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## Greg Elmassian (Jan 3, 2008)

I have. How about you explain the reasoning to me, ok? 

Normally the way cells are charged is a set/controlled current until a certain terminal voltage and sometimes a drop in current, but the drop in current is not used for terminating charge in li-ion.. 

I'm all ears. 

Greg


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## George Schreyer (Jan 16, 2009)

The lower voltage cell will accept more charge until it's voltage comes up to balance the higher voltage cell. However, this begs the question as to WHY a cell has lower voltage on it in the first place assuming that it started out the same as the other cell.


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## Curmudgeon (Jan 11, 2008)

Another to add to my "explosive" file.


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## Michael Glavin (Jan 2, 2009)

Lithium cell technology charger requirements are very basic, constant voltage of 4.2VDC (per cell) with constant current or amperage capabilities sized to provide a variable of the cells rated capacity, (to date its well recognized that Lithium cells can be charged safely at 0.2C to 1C of battery rated capacity). Accordingly a 1000mA cell @ 1C requires 4.2V @ 1A. 1000mA = 1A or 1A is 1C of the cell rated 1000mA capacity. 

In simple words; a single cell Lithium charger provides a MAXIMUM voltage of 4.2V while providing a MAXIMUM current of 1A in my example. 

A Lithium battery charge algorithm requires charging with constant current at a constant voltage until each cell reaches 4.2V, at this juncture the cell(s) will float at 4.2V while the charge current diminishes to termination. When the cells current draw tapers off to approximately 10% of the initial charge current value; charge termination can be executed. Initial charge current values are wholly dependent on the cell(s) state of charge prior to charging with caveats with regard the cell(s) IR Internal Resistance. The charger has NOTHING to with determining current consumption; remember the charger need not be more than a dumb power supply with fixed current and voltage limitations. Each cell recognizes its own needs! 

Time is never a factor nor is voltage in charge termination with Lithium cells! 

Lithium cells charged in parallel individually and or inherently reduce their respective current draw all the way down to say 0.05A for a maximum charge, all of this occurs of their own accord, know outside influence is in play. I’m suggesting the cause and effect equals some degree of cell balancing in of itself. Sooner than later all the cells reach the 0.05A value at 4.2V and are fully charged and balanced. 

Michael


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## Greg Elmassian (Jan 3, 2008)

Yes, and if the lower voltage cell ALWAYS has less resistance than it's neighbors even at the same charge state, which does not necessarily mean it's defective, then it will ALWAYS get a disproportionate amount of current. 

There are precious few cells in the world with EXACTLY the SAME resistance at all charge levels. 

So, there is NO way to make sure the current is divided equally between parallel cells. 

Simple ohms law here... 

The question is how much variation between cells will cause a damaging proportion of charge to go to one cell? 

It's not a good idea. I have seen TWO li-ion cells paralleled in a laptop battery pack, never more. 

What does Rick say about this? He's in the business, so he's seen more battery packs than most people. 

Greg


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## Mike Reilley (Jan 2, 2008)

Greg...the part you are not considering is that with modern LiPos nothing is in parallel for the GRR application. The packs are 4S1P packs normally. A typical pack is a 2650 mah 20C pack...http://www.hobbycity.com/hobbycity/...oduct=8913 . Secondly, these packs are charged through the balancing port (NOT the two wire power port) wherein EACH individual cell is independently charged. If one cell is weaker, then the charger tells you that and reduces the voltage of the other cells to match. So, if you have one cell that only takes a 4.1v charge, the other three "good cells have their peak charge dropped to 4.1v from 4.2v. In general, cells are NOT charged in parallel. Even the bigger 5000 mah batteries are 4S1P rigs...http://www.hobbycity.com/hobbycity/...oduct=6500 .


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## Greg Elmassian (Jan 3, 2008)

Mike, responding to Michael's post, 20th post on the thread, now on the previous page: 

"Since I went this far preaching the benefit of balancing chargers, Lithium cells wired/charged in Parallel ONLY, inherently balance themselves. Confused? 

Michael " 

That's where the parallel configuration statement came from, and as far as I know, that statement is wrong, it makes the assumption that the cell resistances are identical. 

Greg


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## Michael Glavin (Jan 2, 2009)

Greg, 

If the cells source there own needs for current and are allowed to float at 4.2V long enough to have their fill and or current consumption falls off the chart and at that time charge is terminated, what prevents multiple cells in parallel from reaching full charge? Isn’t this a physics thing? 

I’m not suggesting cell IR isn’t a factor I just don’t see how it mitigates each cell from eventually reaching full charge, sure a given cell may be lazier than another but at some point in time it’s all good. Albeit I’m assuming the cells are viable and suspect that the were pulling hairs if we assert a slight intolerance for varying cell IR is going to adversely affect anything… Remember time is not a factor in this circumstance. Lastly since IR or internal resistance is being tossed about Lithium cells comparatively offer VERY high IR specifications as compared to there brethren. 

Michael


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## Greg Elmassian (Jan 3, 2008)

"sourcing there [sic] own needs" is not true, since it seems to imply that they will always consume the proper amount of current. 

A damaged cell won't do that. Poorly matched cells won't do that. Several cells in parallel might not do this well even if "reasonably matched". 

At full charge not all cells have the same resistance / terminal voltage. I did state that several times. If you can refute that statement, then I'll agree. 

1. you may not be able to wait until cells equalize... the current imbalance may be great enough to cause problems, that's why cells are rarely paralleled. 

2. even at the same voltage, one cell could be taking more current than the other, even what you believe is terminal voltage. Over the lifespan of a battery, the "fully charged" voltage varies. That's why the chargers "pick" a "full voltage". 

I am not talking internal resistance, I am talking simple resistance, which drives the current entering the cell. IR is normally related to peak charging and discharging rates. 

You CANNOT speak in absolutes saying putting cells in parallel is fine. If you read what I have written carefully, I use words like "may", "may not", "most likely", "will not always". 

When you say "It's all good", no problem.. that is an absolute... 

So, maybe your cells will blow up, maybe not.... It is always bad? No, is the possibility the charge can be unbalanced? YES. Could this imbalance cause overheating, or worse? YES.... 

With the literally explosive nature of these batteries, trying to make absolute, sweeping generalizations is not right. If it worked all the time, there would be no problems. 

Greg


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## Michael Glavin (Jan 2, 2009)

Greg,

I’m know expert but have spent lots of time playing with and schooling myself on batteries specifically used in the RC industry and I enjoy the banter about same.

I agree ABSOULTES have NO place herein. Furthermore I am not suggesting parallel charging is all that, just that to some degree cell balancing happens when the cells are viable. And I’m thinking the cells would be of like manufacture, like age using cells that have minute differences in internal resistance and open circuit voltage. And of course an intelligent charger would be a plus too.

Perhaps semantics plays a role in our discussion, while it’s more accurate to state higher potential drives current into the cell(s) and the current is a factor of the potentials differential as compared to the cell(s) resistance. Simply stated the greater the gap or difference between the potential and cell(s) resistance, the higher the current flow. This means or implies the cell(s) will consume what’s required to narrow their differential individually. Potential in my example is limited to 4.2V; current flow is a variable of the “State of Charge” (SOC) and cell(s) resistance.

Internal resistance in a chemical cell is due mainly to the resistance of the electrolyte between electrodes. The internal resistance views the conductor from a purely resistive value, or ohmic resistance. This resistance is termed the internal resistance of the source.

Any current in the battery must flow through the internal resistance. The internal resistance is in series with the voltage of the battery, causing an internal voltage drop. With no current flow, the voltage drop is zero; thus, the full battery voltage is developed across the output terminals. If a load is placed on the battery, load resistance is in series with internal resistance. 

Greg from a previous post in this thread you stated:

“Normally the way cells are charged is a set/controlled current until a certain terminal voltage and sometimes a drop in current, but the drop in current is not used for terminating charge in li-ion..” 

That’s not accurate assertion with regard to lithium cells, its well documented that voltage is not a factor, as I alluded to previously conservatively charge is terminated when the current diminishes to 10% or so of initial current at the beginning if the charge.

Michael


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## Greg Elmassian (Jan 3, 2008)

You have brought up a number of points, each of which bears discussion. 

Paragraph 1: I agree, and I like to learn things in addition to the banter. I am not an expert, but very experienced in many battery chemistries, charging technologies and have studied charging techniques for about the last 30 years. (I have studied under experts though)

Paragraph 2: Glad you understand the point about absolutes. That said, reasonably matched cells in good condition will "balance" to a fair degree in a parallel situation. Be aware though, minute differences in resistance makes a surprising difference in charging current. Try this experiment: charge a nicad battery to what you consider full. Now set up a laboratory pwer supply to "charge" this battery and adjust the current to 10 milliamperes. Now increase the voltage by one tenth of a volt and tell me how much the current increases. I'll wager you are surprised. 

Paragraph 3: The first half is obviously true. But you cannot just blindly set 4.2 volts and assume the battery will terminate charging if fed this constant voltage. As cells age, their terminal voltage changes too, even if undamaged. This is the flaw in the thinking. Back to the experiment I asked you to perform. When you see it, you will understand. You need to pick the "right" terminal voltage to a precision way higher than a tenth of a volt also. 

Paragraph 4: sure, of course. 

Paragraph 5: pretty much, although you are ignoring internal leakage (which should be small in a healthy cell) 

Last paragraph: I think you are wrong..funny too, since here you say that voltage is not a factor, but your examples above use a constant voltage... 

I would suggest reading some more on lithium cell charging... most chargers run a constant current (with a voltage limit) up until the cell is 90% full, then switch to constant voltage at that point (using the voltage at the 90% charge) for a set amount of time, usually an actual timer... 

I suggest you Google more charging articles, I think you are quoting a nicad charging circuit algorithm, which now normally use a DV/DT determination to detect end of charge... 

Here's an easy to understand article: *http://www2.electronicpr...>* 
* 
Regards, Greg *


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## Michael Glavin (Jan 2, 2009)

Greg, 

Why are you suggesting I play with NiCd cells and how they behave as these are an all together different animal, I’m discussing Lithium cells and the charge algorithms required and the resultant behavior of same? Anyhow I agree with your assertion with regard to elevating the EMF and the current increase thereof with regard to NiCd's. 

FWIW: I am acutely aware of DV/DT charge algorithms and others. 

Lithium chargers do NOT use time or voltage to terminate charge! The link your referred me to clearly states this as do hundreds of other web pages….. 

Michael


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## izzy0855 (Sep 30, 2008)

Hello everyone, 

Greg, I have read through some of the posts and there's alot of good suggestions and comments about lithium-ion & polymers cells. But, I've been on the road at a trade show in Columbia, MO for the last two days and I haven't had time to post any thoughts. I will tomorrow when I'm back in the office. 

Thanks, 
Rick Isard 
Cordless Renovations, LLC


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## TonyWalsham (Jan 2, 2008)

All of the above is very illuminating for techies. 
I would think that most of it has gone over the heads of the average Joe who is looking for safe cost effective battery power for his (her) trains. 

I am sure they would be extremely interested to find out one way or the other, whether Li-Po batteries can be safely used and charged on board locos without requiring them to be removed for charging. 

Are either of you two eminent gentlemen prepared to spell out whether or not Li-Po batteries can be safely used in such a manner and if so how? 

Can we have an expert opinion please?


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## noela (May 22, 2008)

I look forward to hearing izzy0855's thoughts on the LiON batteries as these normally are applied internally, and removing them from their enclosures would be very time consuming. I would hate to go back to NiMH, but if it's a safety thing, it may be a necessity. Wouldn't do if cars or engines started blowing up, even though the power/weight thing is a big advantage.


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## Dick413 (Jan 7, 2008)

I am with you Tony, I have 5 trains that I have put Li-po's in that I have to take out to chg. [they are 5800mas] put into a can to chg.. 
now airwire comes with a chg. jack for lion. batteries 4400 par. & ser. built.


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## Greg Elmassian (Jan 3, 2008)

Michael, I was asking you to do a simple, 3 minute demonstration to yourself to prove a point about how radically charge current varies with a small change in charging voltage. 

You can do it with a lithium also, I just did not want you to hurt yourself. The point is the same for ALL batteries, I would have hoped you would have taken my word for it, since you did proclaim you were not an expert. 

I know what my link shows, it was in response to your statement about charging, which I believe is wrong: 

"as I alluded to previously conservatively charge is terminated when the current diminishes to 10% or so of initial current at the beginning if the charge" 

I agreed with EVERYTHING you stated EXCEPT that statement. I'm sorry, I thought my post could not have been more clear. 

Greg


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## Dennis Paulson (Jan 2, 2008)

As far as I know , EVERYONE removes thier LiPos from the rc Helicopters and rc Airplanes and rc boats to recharge them . I certainly do . 
My HLW interurban is easy , open baggage door to install or remove the LiPo .


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## TonyWalsham (Jan 2, 2008)

Hi Dennis. 

I understand that your particular locos are easy to get into to remove the Li-Po batteries for charging. 
Most locos are simply not easy to get into, without major surgery to the body work to allow instant access. 

There is no doubt Li-Po are small and have high power for weight. Unfortunately, that alone with will not compensate for the need to charge them in situ, which is what most people want. I am sure that until on board charging can be done safely, most battery R/C LS'ers will err on the side of caution and leave them alone.


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## Daniel Peck (Mar 31, 2009)

Look into Hobby Knig for the batteries and the chargers... the have charges that charge each cell not just the whole pack and it is way cheap from them than buying in the US. 
Look at the Zippy brand batteries and Trunigy Chargers.


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## Michael Glavin (Jan 2, 2009)

Greg,

Are you a battery expert?

Had we been discussing the “what of results of varying charge voltage” and I drew a blank or offered rebutall perhaps I could see the need for my enlightenment. Thing is I fully comprehend, been there done that and lots more. I hope/assumed you might have gathered as much at this juncture…. 

Why it matters in the circumstance of Lithium cell charge termination is still unknown to me, since it’s not a factor as you suggested in determining Lithium charge termination, which is what we seem to be disagreeing on. My experience concurs with everything I have ever read and alludes to my statements one of which you quoted above and I’ll repeat again below.

Conservatively charge is terminated when the current diminishes to 10% or so of initial current at the beginning if the charge.

Again, time and voltage are not represented in determining charge termination of Lithium cell technologies. If you can point me to a source that agrees with your assertions in this regard please do so. 

Most smart chargers offer a user selectable MAXIMUM time “CHARGE ON” interval for any cell technology or charge regimen you employ. This is simply used as a safety and or redundant method to terminate charge, nothing more. Time could be used to terminate charge once the CV step begins, but its not an industry standard and or typical in the hobby industry. 

The Industry recognized Lithium cell technology charge regimen below:

Step 1: Constant Current Charge -- After the cell voltage has risen above the trickle charge threshold, the charge current is raised to perform constant current charging. The constant current charge should be in the 0.2C to 1.0C range. The constant current does not need to be precise and semi-constant current is allowed. Often, in linear chargers, the current is ramped-up as the cell voltage rises in order to minimize heat dissipation in the pass transistor. 

Step 2: Constant Voltage -- Constant current charge ends and the constant voltage stage is invoked when the cell voltage reaches 4.2V. In order to maximize performance, the voltage regulation tolerance should be better than +1%. 

Step 3: Charge Termination -- Current values are monitored during the constant voltage stage and termination of the charge is initiated once the charge current diminishes in the range of 0.02C to 0.07C. 

Michael


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## Greg Elmassian (Jan 3, 2008)

Actually there are normally 4 stages, a preliminary charging stage before the step one above that is used to get the battery in shape for the constant current charge, and also at this point determine if the battery is damaged or should not be charged. (The document I referenced, even though it says 3 stages, explains 4 stages) 

If you put it in the context of the 3rd stage, as in your post above (and 4th stage as I have expressed) then yes, I agree, that charge termination is via a preset minimum current. 

Without the context of the 3rd stage and delineating the 3 stages, then that statement by itself was what I was taking exception to. 

With this context and explanation, I agree with what you said. (although the word "conservatively" does not make any sense in that sentence) 

Thanks for the context and clarification. 

Greg 

p.s. I do not consider myself a battery expert. I know more than most people, but in my mind an expert is someone like TOC on the Bachmann loco mechanicals and internals. That guy is an expert. If I knew as much about batteries as TOC knows about those (and many other) locos, then I might consider myself an expert. I have designed chargers, used lithium batteries for 25 years, and other things that give me a lot of experience... I'm pretty much adverse to calling myself an expert, there's always someone who knows more than me. I guess you asked the question because I chided you for not trying my experiment. I do know more than can be quickly looked up on Google though.


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## carlferg (Mar 18, 2009)

I've been using li-po batts with the recomended charger for on board batt/rc in my On30 locos without incident. However, I always place the loco and charger in our stainless steel kitchen sink when I recharge just in case. Carl


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## izzy0855 (Sep 30, 2008)

I probably will not answer all your questions, but I would like to go back to Steve's original problem and start from there... 

Lithium-Polymers battery-packs are not manufactured with a PCB (unless you request it) and the reason is is because RC Plane & Helicopter enthusiasts don't want their PCB to kick in 200 ft. above ground. Most Lipo user's have four - six battery-packs at one time and swap them out after they have been fully discharged and don't care if they get hot or over discharged, because they want the batteries full discharge capacity while operating their device and thatâ€™s why they have a cell balancing charger outside of their device. Lipo packs are a dime-a-dozen to them, once one fails they have 5 more to take its place. 

Steve, I'm guessing your son's Lithium battery did not have a PCB circuit board installed and that's why the battery got hot and did not shut-off after fully charged. All lithium battery-packs charge cold, if at anytime the battery starts getting warm to the touch remove it from the charger take it outside and place it on a concrete surface. Then call the manufacturer for a replacement. 

So, I would not put a lithium battery in an engine that did not have a PCB manufactured within. I do have three engines (E8, Dash 9 & GP40) that we have installed a lithium 5 and/or 6 cell smart charging circuit board along with a either a 18.5V 5200mah or 22.2V 7800mah lithium-ion battery-pack and have not had any problems for the past two years. 

But, anyone that purchases a lithium battery-pack for us and has it installed within their engine, I always ask these simple questions? 
1.	Where do you live? 
2.	What time of day do you operate the most? 
3.	Do you have room to install a fan within the engine? 

Why you ask? 9 out of 10 times a lithium battery-pack will get warm not due to over-discharge but from ambient temperatures over 90 degrees. For example, think about how your dog feels when you leave him in your car with the windows rolled up and its 80 degrees outside. Acutely it feels like 90 and very stuffy and thatâ€™s what it feels like for a lithium battery stuffed inside a tender. But if you roll the windows down or put a fan in the tender to circulate air, your dog and battery will feel better. 

Greg & Michael, you both have warn yourselves out and you both make some great points defining how lithium cells work and Iâ€™m not sure where to startâ€¦but, in regards to Gregâ€™s response to less resistance to neighboring cells. You'll remember this . . . I have rebalanced many cells in parallel packs that have been discharged with a variance greater than .03volts per cell and havenâ€™t displayed any type of capacity loss or damage to the cell. This just happened this past week where a customer shipped us his battery-pack finding that one cell was charged to its full capacity of 0.9V and the other three were fully charged at 4.2V ea. We rebalanced this one cell back to 4.2V, balanced the entire pack back to 14.8V, ran it through 3 cycles on our analyzer and did not see any loss of capacity during these three cycles. What may have caused this was storing a lithium battery in temperatures lower than 40 degrees for long periods of time, or the manufacturer did not balance the cells prior to shipment. 

Michael, in response to your constant voltage charging a lithium batteryâ€¦is real close. Like normal, lithium chargers charge the number of cells in series and equally in parallel and not the voltage of the pack. I disagree with your, â€œThe charger has NOTHING to do with determining current consumptionâ€� statement. All of my smart chargers have a tapered variance voltage, meaning if Iâ€™m charging a 14.8V 2600mah lithium-ion battery-pack for the first time my smart chargers will only charge 40 â€" 50% of the batteries capacity, or until the PCB decides that this is all the energy that this battery-pack can take until you discharge it. You canâ€™t force feed a rock and each cell doesnâ€™t recognize its own needs, that is why we manufacture a PCB circuit board in every pack. But, a smart charger (at least mine donâ€™t) donâ€™t charge a battery-pack with constant current till it reaches 4.2V per cell, that would damage the cells. All of my smart chargers recognize and reads how much energy the battery can take at one time until the rock is discharged. 

I probably forgot something and Iâ€™ll check back later, 
Rick Isard 
Cordless Renovations, LLC


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## Michael Glavin (Jan 2, 2009)

Rick, 

The charger can be dumb as I previously alluded to, but needs user input to switch between CC/CV and charge termination. The reason I mentioned this was to help others disassociate the need of the charger to regulate and or influence the cells current consumption when CURRENT and VOLTAGE parameters are in play. A power supply regulated to 4.2V and the appropriate charge current (1C) for the cell under charge will suffice for charging a single Lithium cell…… 

Contrary to your assertion, a viable Lithium cell in laymen’s terms will ONLY consume what it needs without outside influence of a charger. That said a chargers algorithm can be wrote to accommodate a variable as you suggested, is it a pre-requisite NOT! I described the how and why in a previous post herein. 

Are you suggesting your SMART charger relies on the safety circuit or as you note PCB to terminate charge, if so how smart is it? I would inject the charger more likely than not works the same as most industry standards and terminates charge based on a percentage of the initial charge current and uses the PCB as a secondary or redundant termination method, BUT you could save a buck or two by relyng on the PCB with the net result of a partially charged battery.

If your charger doesn’t charge with CC until the cell reaches 4.2V like the rest of the industry your increasing the charge time considerably, without merit.

If your chargers “recognize and reads how much energy the battery can take at one time until the rock is discharged” you’ve developed a protocol the rest of the battery world would be envious of.... 

Michael


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## Michael Glavin (Jan 2, 2009)

I NOW believe given the current technology afforded us with Lithium cells and cell BALANCE chargers together with safety circuits its reasonably safe to charge your Lithium cells while installed in your loco, tender, trailing car or what have you. That said there are caveats, good old common sense and knowledge of the cell technologies requirements to safely operate the charger in play is at the top of the list, second is location-location-location and a proper fire extinguisher nearby is prerequisite IMO.

Pictures below are of my LGB Mogul with Vanderbilt tender with six Lithium 18650 cells in series with balance charge pigtail in place, no safety circuits. Albeit a safety circuit is certainly applicable. The balance port charge socket is located under the coal load adjacent to the G-Wire RX. This is a very straight forward simplistic installation given the space constraints.

QSI Sound/decoder with G-Wire RX.
Six 2200 mAh cells in series producing 22V.
2.5mm Charge plug which doubles as an ON-OFF switch.
7-conducotor balance port charge socket.

Michael


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## Alan in PA (Feb 5, 2011)

Has anyone tried EneLoop batteries yet? 

They are NiMH but somehow don't self-discharge appreciably. 

Alan in PA


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## Greg Elmassian (Jan 3, 2008)

Yes, Tony Walsham uses them extensively, recommends them highly. I have several in the AA size, and yes, internal self discharge rates are lower. 

Regards, Greg


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## wigginsn (Jan 9, 2008)

I use Matsushima low loss NiMH's (AA), similar technology to the Sanyo I am given to believe. 

Still getting good results 2 yrs after installation. 

Cheers 
Neil


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## Greg Elmassian (Jan 3, 2008)

Looked them up, yep seem to have similar product. Not easy finding a vendor in the states, only alibaba for the AA's on a quick search. 

Greg


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## izzy0855 (Sep 30, 2008)

Michael, 

Your installation looks good, but a couple of suggestions if I may. If you haven't because I can't tell from your pictures, please insulate the ends to your Garmin 330 lithium-Ion cells, that's what they look like? Lithium cells are known to ark a spark between cells or connections if there not insulated properly. Everything else looks good, love the QSI Magnum system and it looks like you have room for a small fan? Also, it looks like you used a small portion of hot glue between the cells, if you notice the cells separating during the summer months I would suggest using a drop of super glue to keep them together. 

The later of the two enquiries about our CR-1 Smart Charger. The CR-1 was designed to read how much energy during a charging cycle a battery-pack can take, this percentage is displayed on the side of the charger through a 5 LED gas gauge. The gas gauge reads the energy that is discharged and charged in increments of 20% during a charging cycle, and will let you know when your battery-pack (NiCd, Nimh, Lithium-ion or Polymer) has 10% of energy left by flashing the 20% LED until you recharge the battery. All of my chargers are designed to read the capacity of your battery-pack through cycles and not overcharge the cells decreasing it's consumption. That is why when you charge one of your battery-packs with the CR-1, it will only charge about 60% of it's full capacity during the first cycle, it needs to learn how much energy your battery can take from charging and discharging. 2-3 cycles for NiCd/Nimh packs and 3-5 cycles of lithium packs. 

Have a great Superbowl Sunday, 
Rick Isard 
Cordless Renovations, LLC


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## TonyWalsham (Jan 2, 2008)

Posted By Alan in PA on 06 Feb 2011 06:54 AM 
Has anyone tried EneLoop batteries yet? 

They are NiMH but somehow don't self-discharge appreciably. 

Alan in PA 


ENELOOP batteries are made by Sanyo. I have been using them ever since they were first available here in Australia some years ago.
They are only available in AA and AAA sizes at present. They are a mixture of Alkaline and NiMh chemistry and were developed specifically for use in Digital cameras. They are sold fully charged and are guaranteed to hold 85% of charge for one year.

Panasonic have their own brand as do other makers.

I have to use them where SubC cells will not fit as other sizes of NiMh and NiCd are extremely expensive here in Australia.

The are only two real problems with ENELOOP cells.
One is, that like regular NiCd and NiMh AA sizes, there is a limit on the amount of current they can discharge at. The maximum draw, according to my supplier, is about 1 amp. Any more and and the life span of the cell is reduced in terms of the number of recharges.
The other problem is they do not come tabbed for self soldering. They must be welded together to assemble a pack. Soldering them WILL[/b] definitely damage them.

Are they perfect? No. But, seeing as they are the only really affordable alternative here in Australia I am happy to recommend them. Especially as my Sanyo distributor refuses to supply Li-Po batteries because of safety fears.


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## steamhostler (Jan 1, 2022)

Michael Glavin said:


> That said I totally agree Lithium cell technology can be and is dangerous with the uniformed and informed alike. Do NOT become complacent with your batteries. Safety is paramount, a fire extinguisher nearby, an adequate charging enclosure of some sort has merit and perhaps charging on the kitchen table is a bad idea; an open area is best IMO.
> Michael


As a new R/C Live Steam user, I've read this older post and learned of the dangers of Lithium batteries. I'm using Li-Ion type batteries that come with their own specific charger.
Since reading this information I've stopped charging Li-Ion on the kitchen table and instead charge them on the floor of the fireplace. Thanks for the heads up!


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## Pete Thornton (Jan 2, 2008)

steamhostler said:


> I've read this older post


It is an old post and batteries have come a long way since then. Most now have a 'protection' circuit which prevents them being undercharged (which kills them) or overcharged (which overheats them.)

I've been charging LiIon batteries inside my locos or on my wooden bench for the past 5 years without incident.


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## Greg Elmassian (Jan 3, 2008)

Steamhostler, I know you are new and enthusiastic, but please don't fly all over the site and revive really old threads just to add on. This one is over 10 years old and the technology and the "common wisdom" has changed.

You have friends, which of yours has had the dreaded "lithium battery fire"? None, and yet compared to 10 years ago, I would wager there are 20 devices in your house with lithium batteries.

Greg


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