# Good disertation and data on LiPos



## Curmudgeon (Jan 11, 2008)

The safety items are long.
Wade through them, get to the list of fires, explosions, houses, trucks, cars, etc.

There's a lot more where this came from.

http://www.rcgroups.com/forums/showthread.php?t=209187


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## Mike Reilley (Jan 2, 2008)

Yes there is...and those RC guys fly those expensive planes everyday...and recharge their batteries safely. It's all a matter of getting used to operating these batteries safely and taking some precautions. Zero risk is NOT possible with any energy source. LEARNING how to use these new batteries is important...and you posted a link to a site that for a long time has been my research base and has had the leading information on how to use the Lithium batteries safely. It's good stuff to read ALSO from the standpoint of using the technology safely...and NOT just as information to scare you away. 

Go to http://www.mylargescale.com/Community/Forums/tabid/56/forumid/23/tpage/4/view/Topic/postid/105434/Default.aspx page 4 to see what I'm talking about.


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## Curmudgeon (Jan 11, 2008)

The safety data is of primary importance. 
I'd seen it before, had to dig it out. 

You follow the lists of houses, cars, trucks going up in flames? 

To me, monitoring charge AFTER insuring cell balance on all cells, and having about 3 years from date of manufacture (not entered into service) is not on. 

Promising technology? 
Maybe. 
But the charger technology still is not caught up with the batery technology.


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## East Broad Top (Dec 29, 2007)

Seems to me that the advice given relative to the safe use of Lithium batteries has a very familiar ring to it. I'm fairly certain "use only an approved charger," "don't overcharge," and my favorite "don't puncture" apply pretty universally to all battery technologies. The only difference is the level of potential threat should the rules be violated. I'd be willing to bet that the number of households with some form of Lithium battery technology under the roof is fairly high. As I look around the room, I've got one in the laptop I'm typing on, there's one on the wall charging, one on the counter that needs to be charged, my cell phone on my hip, and my mogul sitting on the shelf. Statistically speaking, electrical fires account for around 1% of all house fires--what percenatage of that 1% is caused specifically by Lithium batteries is unknown. "Natural" which includes lightning and wildfire accounts for nearly twice that (1.9%). Cooking tops the list at 26.4%. 

Source: http://www.usfa.dhs.gov/statistics/national/residential.shtm 

I'm not saying the risk isn't there. I'm saying it's not as great as is purported on the web and on YouTube videos. The local fire departments aren't asking for reinforcements because more people are charging their cell phones. Read, learn, play within the rules, and make your own determination as to whether the technology is right for your use. 

Later, 

K


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## Cougar Rock Rail (Jan 2, 2008)

OK....just went through TOC's list and watched the overcharging video. Holy Cow! Any thoughts of changing my electric Spitfire over from Nicad to Lipos have now been extinguished. I've talked to lots of R/C plane guys at our local school field, and every one of them has had one form of disaster or another with Lipos. Most say they use their BBQ's to charge in. 
No thanks.... 

P.S.
I should add that my experience with battery chargers has been that they are one of the most unreliable electrical devices made, so even if I could trust myself to follow the proper procedures, I still wouldn't trust the charger...no matter where it's made....


Keith


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## Curmudgeon (Jan 11, 2008)

http://www.evcbattery.com/image/EB721datasheet.pdf 

http://en.wikipedia.org/wiki/Soldering_iron 

There are some who advocate not only ignoring of safety specifications, but also advocate doing things with LiPos that are downright dangerous. 

Refer to exhibit 1. 
Read the temperature ranges of safe operation, read 140F (60C) as the top end. 
Then, towards the bottom, it says NEVER solder directly to a LiPo battery. 

Now, refer to Exhibit 2. 
Read the lowest temperature of a controlled lead soldering iron. 

250C (482F) MINIMUM! 

So, if someone who claims to be able to solder directly to a LiPo encourages folks who do NOT know to do this, and they overheat, we all know who to blame. 

But, I am purposefully being non-specific. 
Just remember Hill Street Blues....and let's be careful out there.


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## astrayelmgod (Jan 2, 2008)

"There's a lot more where this came from." 

When I worked for GM on their electic vehicle program, several people there pointed out that if battery powered cars had been perfected at the beginning of the 20th century, and we were trying to build a gasoline powered car, everyone would say, "you're crazy!! You can't put that dangerous gasoline in cars!!" We went to great lengths to be certain that our battery cars were as safe as gasoline powered cars. 

My point is that we don't abandon new technology, we add safety features to make it safe to use by anybody, including people who may not be paying attention to every last detail. I didn't read every item of the failure list, but I observe that if the charger could sense how many batteries are attached, and what their chemstry is, and the state of charge, many of those failures wouldn't have happened. 

Until that happy day, read the instructions, use a dedicated charger, match your charger to your batteries, and don't walk away while charging.


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## billsharron (Jan 3, 2008)

Gotta watch out driving those dagnabbed automobiles. Look at this data http://www.usfa.dhs.gov/statistics/national/vehicles.shtm and the number of deaths per 1000 fires, http://www.usfa.dhs.gov/downloads/pdf/tfrs/v9i1.pdf And that is only for car fires not highway accidents. I have li-ion batteries in my cell phone, newest JVC cam corder, in my two laptops, and in my trains, and posssibly my newest electric shaver, and perhaps other things that I don't even know about. I have no plans to stop using them. as for Lipos I don't think any of my electronics have them, at least not that I know of. 


I am with Mike and Kevin and others on this issue, There is risk in everything we do, and properly following instructions is very important. LIPOs are way to expensive at least for me and I do not plan to use them or solder to them. For now I will stick to the Li-Ion batteries, which have proven to be trouble free to me and to many of my train pals who use them.


Last week at the National convention in Denver, I finally had the chance to use some Li-ion 14.8 volt 2600 Mah packs on one of the display layouts. It had a 5.2% grade on about a 550 foot mainline along with some 4% and 3%. 2 Bachmann Connies and a Bachmann Annie all r/c and all with sound ran all day pulling 4 to eight cars without a battery change. We ran a unit coal train with 2 USA Trains GP38s, 12 Aristo hoppers with loads, and a USA Trains caboose using only ONE 14.8 volt 2600 Mah Li-ion battery Pack. The dismals as Dave calls them, were equipped with Phoenix 2k2 sound. The 27 mhz receiver and battery was in the first hopper. This train ran for just under two hours on just the ONE battery charge up the 5% grade with no problems in 95 degree heat. The train speed at full throttle was more than enough and faster than I felt comfortable running. There was no difference in performance between the factory made Li-ion battery packs and the home made ones I make. 


Battery power was a big topic of many of the visitors. More and more are going to battery. Many other Li-ion users all reported no problems and no failures. Some even recharge their Li-ions in their locos. I estimate that I talked to at least 40+ users of Li-Ion batteries. Some do not use any special care other than using the correct charger. No one I talked to used LIpo batteries. LIPO seems to be more popular among the European contingent. I talked to several German nationals visiting the convention and two were using LI-ion batteries with no problems. 



For now I will stick to Li-ion over the LIPO batteries till the price comes down and more is known about how to use them more safely.


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