# So, what is the real truth about Li-Ion Batteries?



## billsharron (Jan 3, 2008)

It is time to get the facts about Li-Ion batteries, after reading qiute a few threads there seems to be a great deal of confusion about the subject!!!! 

Some say stay Li-ion batteries are dangerous and or blow up all the time, TOC won't use them, nor will many others. Others swear by them, saying they have used them without incident for some time. 

I only know of one actual case where a Li-ion battery overheated and caught fire. I have them in my laptop computer and have never had a problem with them. 

Others say that the Li-Ion batteries are so bad they must be charged in a fireproof container, something which will not be practical for me anyway. 

Studying the situation, I learned that you must not overcharge them! So it is critical to have a battery charger that cuts off if the battery starts to over charge. If the battery charger is defective the next important thing is to be sure you have a battery pack with something called a PCB board to prevent overcharging. 


So what is the real truth?? Can I safely use a smart charger and a PCB protected Li-Ion Battery?? 

Facts, Just the facts, no guessing/DesktopModules/NTForums/themes/mls/emoticons/laugh.gif no speculation, Just reality!!!!/DesktopModules/NTForums/themes/mls/emoticons/whistling.gif


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## Greg Elmassian (Jan 3, 2008)

Li-ion CAN be dangerous... need more care 

TOC will not use them 

Careful people can have good luck... 

The guys that use the fireproof containers are usually model aircraft people, and they run the batteries much harder, discharge and charge... 

ABSOLUTELY CRITICAL you use high quality li-ion charger. Li-ion batteries cannot take any overcharge, must shut off completely at charge completion.. 

Don't need battery pack with "brains" but it helps... 

Greg


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## K27_463 (Jan 2, 2008)

There are many things misunderstood about Lithium packs. The early reports of overheating and fire were the result of misuse, or use under very harsh conditions. The electric park flyers using Lithium pull literally hundreds of amps from the cells under full throttle, and can drain a pack in mere minutes, then recharge immediately-allowing no time for the pack to rest or cool. Our trains on the other hand pull only an amp or three normally and will not heat the cells so severely.Nor do we fast charge our packs immediately upon discharge in order to get going again a few minutes later. I have been experimenting with my own trains and Lithium for over 2 years with very satisfactory -I could even say outstanding, results. 
Lithium construction and charging technology has improved greatly in the last few years. Those people that have publicly stated they will not use Lithium said exactly the same thing about NIMH years ago-Look it up- it is in the archives of this site, and are now happily selling them. The same was said about fast charging-also in the archives- but now are offering fast chargers for sale. Technology improves.Science marches on. 
I had a very long technical discussion with a very highly qualified expert in the field at the Arizona Convention. Knows more than I do and I have been doing the battery thing since 1990 and in electronics since the 70's. The scientific advances in Lithium cell performance have been marked in the last few years, especially since the SONY recall, from which much was learned. The large Japanese electronics companies -Panasonic-JVC-Sony and more would not offer Lithium batteries- to be used in doors- if their testing had not gone well, and the company did not consider it safe. If a client convinces me under questioning they understand and know what the discussion is about, then I will offer them the option of lithium, have been doing this for over a year. 
A dedicated or function specific charger is mandatory. The protect PCB now included in almost every pack is designed to limit both overcharge and overdischarge, and they work very well. 
With all this being said, unless space is critical, there is still little advantage in many applications because cost remains higher, and unless you can get a dual function charger that handles both LI and NI chemistry ( they do exist and are for sale), charger costs increase also. 
Lastly, there are two kinds of Lithium. Lithium -ion is more common, has lower costs, and is more "conventional" if such a word applies. Lithium -polymer, on the other hand, has a higher cost, but creates an even smaller cell for a given charge density, which also weighs less(not that much of a factor for us). For our uses, the two lithiums represent essentially similar performance curves with no reason to recommend the polymer over ion , and in fact ion will save $$. 
Charging of Lithium packs is done at a constant voltage AND constant current, with a good charger auto switching to a trickle level when the pack reaches a level within 5% of full capacity. Normal Delta V peak detection does not work with Lithium, so a charger with a display of some sort, either lights or digital, is much preferred. In this way you have double level control , from the charger's smarts and from the board included in the pack. 
It will only continue to get better. We are a small market but we can benefit from all the development going on around us. You already use lithium in your cellphone, your home cordless phone, your digital camera, and other devices.


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## altterrain (Jan 2, 2008)

Besides your laptop they are in cell phones, ipods, digital cameras, etc. There are millions of them out there in use. Problems arise when impurities are in the batteries from the manufacturing process. I have picked up a few packs for some small 7/8s scale loco projects. I get the Tenergy packs from all-battery.com. Each individual cell has an overcharge protection pcb (printed circuit board) built in. They sell a specific lithium pack charger for about $23 bucks. I do take care to charge them on a non flammable surface. 
-Brian


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## rthazen (Jan 2, 2008)

They are used in several auto applications. Electric dragsters are raced. The Tesla is in production but over $100K. Where next I wonder.


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## lownote (Jan 3, 2008)

I'm surprised they are such a problem. I have a Hitachi 18 Lithium Ion drill that I really really like. It holds a charge a long time, it recharges quickly; it's much lighter than other battery packs and so it's less fatiguing to use. It's been completely seamless and trouble free for me. The Hitachi charger is relatively big and takes up some space, but I just plug the spare battery in and leave it. It never gets hot or gives me any cause for worry. Obviously this is a very different application from a train, but my one experience with L-ion has been entirely favorable


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## billsharron (Jan 3, 2008)

K27 463, Thanks for the detailed response, I very much appreciate it. I have been looking at the Li-Ion battery packs & chargers metioned by allterrain(thanks) and like them for the small size. 

I have decided to skip the older technology batterys and go with this latest technology. 

Thanks to all for your responses!!


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## acmartina (Jan 6, 2008)

Bill, 

I have used Li-Ion batteries from BatterySpace.com and AristoCraft in my trains for a couple of years now without event, as have many others. They are compact. They don't have a memory effect. They have a circuit board to control the charging. 

I have a friend who is heavily into RC airplanes. He has used NiMH and Li-Po, and had melt-downs with both, so there ar no truly safe batteries, regardless of chemistry. I have heard third-hand stories about other people with problems with Li-Ion batteries but I have so many electronic devices using them that I suspect it has gained much more attention than merited. 

I am not any kind of battery expert, or anything more than a consumer of them, but IMHO, the risk of Li-Ion batteries is mitigated to the same level as NiMH or NiCAD by use of a proper charger and PCB. 

Steve H. 
Cypress, TX


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## Stan Cedarleaf (Jan 2, 2008)

Bill, I've been using 7.2 and 14.4 2000 mah Li-ion packs for more than 2 years with great results. I charge them with the recommended chargers from Batteryspace.com where I get the batteries. I don't charge them with anything other than the recommended chargers. Only had one pack fail which had a bad cell. 

On the flip side, I've had ALLLLLL the nicads and Nimh packs fail with bad cells or cells that exploded. Yes, I used the recommended charger with them as well. 

For my larger, multi-locomotive consists pulling long trains, I still use the old, reiable 12 volt 5 amp hour gel cells in battery cars. They work wonderfully and charge with standard 12 volt Wal-Mart chargers. Been using some of them for 5 years and they are very cost effective.


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## billsharron (Jan 3, 2008)

Steve, Stan, Thanks for the replies. Stan do you charge the batteries while they are onboard the loco? or do you take them out and charge them in a fireproof box?? What kind of damage did you experience when the NIMH batt exploded?? When I think about it an explosion while in my locos is my biggest fear!!


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## Torby (Jan 2, 2008)

I went with NIMH 'cause I could get a deal on 3.8AH batteries and have lots of space in the tender. 

Be sure you get a charger built specifically for LI and you'll be fine. I think they have the spontaneous explosion problem licked.


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## Madstang (Jan 4, 2008)

I use the Aristo and Milwaukee Li-on batts...no problems yet...should I be having problems??? 


The only thing I don't like about the Milwaukee Li-on batts, is that when they are spent and needing the train will stop abruptly...no matter where the train is. 

I have not run the trains running on the Aristo batts much yet but no problems yet. 

Bubba


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## K27_463 (Jan 2, 2008)

Madstang, the reason for the sudden stop is that the pack has a cutoff circuit inside it. This is done to avoid overdischarge, which can cause the pack to fail recover during the next charge cycle. The same circuit also prevents over charge to avoid related problems. This circuit really helps the life of your battery pack and is a benefit, just keep track of running time -approximately, so you know when to change. Partial discharge has no long term effect on the pack-so just stop when in a convenient place near the end of the time allotment. 

Jonathan


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## Stan Cedarleaf (Jan 2, 2008)

Bill, I've always charged the batteries outside the locomotive/battery car. When one set is discharged, I just plug another in and keep on going..


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## Torby (Jan 2, 2008)

Sudden stop? Oh yea. Any modern rechargable stops suddenly. When my Mallet starts to slow, you have about enough time to say, "I think I need to change," before it's stopped.


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## Greg Elmassian (Jan 3, 2008)

Tom, there is not normally any circuitry between the battery and the load when using nicads, gel cells, or nimh batteries, the output of the pack is normally a wire welded to a cell. 

On lithium rechargables, there is almost ALWAYS a circuit between the cells and the outside world, and will cut of the batteries once they fall below a certain level. 

Thus lithiums will quit abruptly, while others will slow down and down. 

Often they will appear to be at full output voltage up until they disconnect. 

Regards, Greg


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