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Old Aug 10, 2003, 07:57 AM
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Joined Jan 2002
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Fire resistant safes have a door seal - meant to keep heat out.
To contain a battery meltdown, a vent hole may be needed, so the safe won't pressurize. Charging wires could run through the vent hole.

Being insulated, they will quickly get VERY hot inside. But the exterior surface should stay cool long enough to carry the safe outside.

- RD
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Old Aug 10, 2003, 02:21 PM
Use the 4S Luke
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USA, TX, Euless
Joined Aug 2003
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If you don't lock it, the lid could be lifted by any pressure and you've got to run the wires in under the lid anyway.
These things are made to withstand a structure fire with minimal damage to the papers inside so I expect they're lined with something like the firebrick in your fireplace. Leaving the lid down would limit the oxygen available for combustion. This may not matter because I don't know if the battery supplies its own oxygen during a failure or not. Any battery people out there know?
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Old Aug 10, 2003, 04:41 PM
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United States, NV, Reno
Joined Mar 2000
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I still think a fireproof barrier (like tile) with a clear area around it (like the garage floor) would be best when it's not possible to keep an eye on them (like at 2am). Other than that, during transport to the field, a plastic baggie and a tile on the floorboard and an stray eye on it would work, and keep them out of the car on the tile when not in use at the field. I'm updating my fire extiguisher just in case, but it's a good idea anyway to have this sort of attention to potential hazards in the home.

This is a good brainstorming discussion at minimum.
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Old Aug 11, 2003, 11:25 AM
Alphabandaid
Marshfield, Wisconsin, United States
Joined May 2003
1,259 Posts
Fire Proof Battery Container?

Wonder if something fireproof qould be a good idea to hold and trnasport batteries at home and n the car. Any ideas?
I'll wander Wal Mart and others and report back.
Stuka
PS my reject and broken tabs cells are going out in the trash in stead of in the basement polastic tray.
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Old Aug 11, 2003, 12:20 PM
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Charleston, SC
Joined Jul 2001
85 Posts
Redundant Safety

My viewpoint after following these issues for months:

1. Overcharging caused by either Charger failer or operator error seems to be the biggest danger. In dangerous industrial process systems such as refineries or handling chlorine, an independent safety system is required in case the main controller fails. A separate device using relatively simple circuits could be designed to monitor maximum voltage and wired to shutdown the charger. This would provide a redundancy for safety. Perhaps the device could be supplied by the battery manufacturer specific to the battery pack with a fixed setting or with a special plug to prevent operator error. A device with an adjustable setting for different voltage packs would be more convenient, but would have to be set correctly.
While I have a fireproof material for charging, I still tend to leave the battery in the plane to charge because it is is very difficult to get the pack out. I just don't trust the method of using Velcro to strap in the battery. I'm looking for some sort of strap with a plastic quick disconnect fastener that would allow easy removal. Any ideas??

2. At the field, in case of crash and puncture, I will be bringing a gallon of water, fire extinguisher and a pair of high temp gloves.

Gary
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Old Aug 12, 2003, 11:49 PM
I Hope they brought pizza
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Just Beyond the Vanishing Point
Joined Mar 2002
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After reading this thread, I too have revised some of my charging and storage methods. I now use a terra-cotta pot--flower pot--filled with damp play sand to both charge and store Li-poly's.

The storage process is nothing more than placing the battery pack in a zip type sandwich bag, gently tucking it into the sand "bedding", and placing the pot on a non-combustable surface away from other combustable stuff.

To charge the pack, open the zip type sandwich bag, connect charger....etc. The pack is charged while resting on the sand which is contained in the pot.

The small flower pots are readily portable, and do not tip over easily in a car during transport. I supose a couple of flower pots could be set-up inside a milk crate for even better stability during transport.

Anyway, FWIW....I have better peace of mind with it. And yes, It would take a lot of energy to turn that flower pot full of sand into a blob of molten glass.

Oh yeah, don't forget to seal the drainage hole in the bottom of the flower pot....It seems that spilled sand, a kitchen floor, and a tired spouse are reactive...one must use caution.

Mark
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Old Aug 13, 2003, 12:08 AM
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Joined Aug 2003
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To add my story, I also had lipo's catch fire. I will admit that my charger (one that is supposed to correctly charge lipo's) incorrectly put in more amps and created a problem, but the results of this were not nice.
I was working at my bench and charging batteries (my first LiPo pack) when I heard a crinkeling sound. Saw that my LiPo pack was swelling up so I quickly disconnected it. I expected that it would cool down being disconnected, on it's own and left it be. As the swelling seemed to be abating I figured I was only out a new battery but that was all.
Wrong! 10 minutes later the pack exploded showering sparks in a 20 foot circle. I ran for my fire extinguisher and was about to let it go when the other side of the pack blew also. (2 cells -1300mah) More sparks and finally much powder all over the place and my planes, bench etc.
I admit I am at fault here, but advise the following:
These batteries must never be charged without supervision even though they take a long time. If I had not been there I may have lost my house! (Never mind the irate spouse)
These batteries cannot be trusted after any unusual event, such as hard landings etc. We will continue to use them in our hobby, for sure, as the power of advertisements and marketing will go on. However, I thing there is a level of negligence on the part of manufacturers and vendors, in that needed warnings and advice are, in my opinion, seriously lacking.
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Old Aug 13, 2003, 01:53 AM
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macon, georgia
Joined Jun 2002
57 Posts
here is my charging station
its in the den/computer room where i can watch it
also have one of those red blinking LED buttons flashing when Im charging
only been using Li-polys for about 2 weeks
Got my first one's from Doug at SEEFF for my Tantrum
Have yet to solder up those single et-1200 cells to packs
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Old Aug 13, 2003, 01:58 AM
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Rochester, MN
Joined Nov 2002
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Korundal, Absolutely brilliant use of the "fireplace" . I hope it's an omen of the things to come
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Old Aug 13, 2003, 04:54 AM
Little Bo's Lab
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Dayton, Ohio
Joined Apr 2002
241 Posts
Fireplace Great Idea But!!!

The Fireplace is a great Idea but I would also add a fireproof box to hold and contain the LiPos while charging and storing...if sparks can fly up to 20 foot (see comments this thread) they would be shot out of the front of the fireplace and into the room with carpet, sofas etc.... You could use a firescreen in front of the fireplace and that could help.

I believe the manufacturers of these batteries need to place a warning label as well as design a special fire proof charging and carry case to transport and store these batteries and do it fast. Li means Lithium metal which is the lightest metal on earth...if it burns similar to Magnesium then we could be in trouble...and we definitely need to treat these type of batteries like a loaded gun...you need to be able to remove the battery after each flight and store and transport in a special box.

I'm purchasing a fireproof box to store these batteries in immediately ( and store in garage or shed away from any combustable material) and will charge only with 100% supervision...also if these fires are extremely hot...burning Lititium metal fires...then you need a fire-extingusher designed for these type of fires.
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Old Aug 13, 2003, 06:43 AM
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Joined Aug 2003
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The "sparks" in my case were of various sizes based on the embedded bits in my foam work board. They ranged in size from sand grain to pieces about the size of Grape Nuts cereal. Up close the burned into a wood chair and melted holes through the 2" foam work surface on my bench. The appearance was of a ground type of firework display with a shower effect.
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Old Aug 13, 2003, 07:38 AM
Space Coast USA
hoppy's Avatar
Space Coast
Joined Oct 2000
21,116 Posts
This should be a sticky and required reading for all LiPo users.
hoppy.



Quote:
Originally posted by dimberio
To add my story, I also had lipo's catch fire. I will admit that my charger (one that is supposed to correctly charge lipo's) incorrectly put in more amps and created a problem, but the results of this were not nice.
I was working at my bench and charging batteries (my first LiPo pack) when I heard a crinkeling sound. Saw that my LiPo pack was swelling up so I quickly disconnected it. I expected that it would cool down being disconnected, on it's own and left it be. As the swelling seemed to be abating I figured I was only out a new battery but that was all.
Wrong! 10 minutes later the pack exploded showering sparks in a 20 foot circle. I ran for my fire extinguisher and was about to let it go when the other side of the pack blew also. (2 cells -1300mah) More sparks and finally much powder all over the place and my planes, bench etc.
I admit I am at fault here, but advise the following:
These batteries must never be charged without supervision even though they take a long time. If I had not been there I may have lost my house! (Never mind the irate spouse)
These batteries cannot be trusted after any unusual event, such as hard landings etc. We will continue to use them in our hobby, for sure, as the power of advertisements and marketing will go on. However, I thing there is a level of negligence on the part of manufacturers and vendors, in that needed warnings and advice are, in my opinion, seriously lacking.
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Old Aug 13, 2003, 08:09 AM
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Walled Lake, MI, USA
Joined Feb 2000
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Dimberio, your story is unique in that it is the first firsthand description I can recall of a LiPo pack that "exploded showering sparks in a 20 foot circle." If it's true that LiPos can behave this way, that does not seem to fit with all of the earlier descriptions of soft-case LiPos being safer than hard-case Li-ions. You say that your LiPo cells were 1300mAh. This seems to be an odd size for LiPos. I am aware of some 1300mAh Li-ions, but not 1300mAh Li-polys.

EDIT -- The more I think about this, the more I think that we really need to determine if these 1300mAh cells that "exploded" were Li-ion or Li-poly. The last time someone described Li-poly cells "exploding," it turned out they were actually Li-ion cells. Dimberio, could you please give us a little more information about your lithium cells so that we can understand exactly what they were? -- EDIT

It's really a shame that we don't have any true Li-poly technical experts participating in this thread to give us some factual data. In the absence of good technical input, this discussion will only produce more speculation about the potential dangers posed by LiPos. If I were earning my living selling LiPo cells and chargers right now, I'd be extremely concerned. It may be time for all of the LiPo business competitors to get together and speak with one voice on the safety issue.
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Old Aug 13, 2003, 01:02 PM
Space Coast USA
hoppy's Avatar
Space Coast
Joined Oct 2000
21,116 Posts
Here's one - http://cellphones-accessories.com/samsc8118508.html

Looks like they make both flavors in the cellphone world. You are right, for accuracy sakes, the identiity should be confirmed. On the other hand, I'm not so sure that a well shrinkwrapped/taped pack of lipos wouldn't react in the same way. Anybody want to donate some packs for testing?

For informational purposes - Li-ion and LiPo cells DO NOT contain elemental Li and do not burn in the fashion of the Li Metal batteries. The Li-ion, Li-ion Polymer cells have an organic compound inside that can ignite when it contacts air.
hoppy
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Old Aug 13, 2003, 01:33 PM
PittsLover
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Ohio
Joined Jul 2003
914 Posts
Well, enough of this.......
I am a BIG believer in all of the advantages of lipos.......and I am also a cautious person. Just went to my local Lowe's and bought a small "Sentry" fireproof box....rated for 1600 degrees for one half hour.......inside measures about 12x7x3........perfect for the car trunk and for the charging table................$19.95 each. I mean, we pay $35 for a 2S1P of 1200 ETec's....for another $20, I will feel a whole lot safer when those puppies are chargiing and I am not with them......

Jim
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