Want to see what $1200 worth of LiPos look like?

[Grimracer]

Lohring.. have you seen a lipo fire..

If not and you can spare an old battery.. it might be a good idea to become acquainted with one..

If nothing else you can impress your buddy with one and BTY keep a good class D extinguisher handy.

And by all means.. do it outside on the dirt. It will make some nasty looking marks in your driveway.

Grim

LIPO SACK TESTING IS FUN!!!

 

[Bill-SOCAL]

my only question and i am not a lipo fan at all.. is why spend that much on batteries that you chance losing or burning the whole mess down like this one.. and they are not faster correct?

I have two of the exact same mono hulls, one is gasoline and the other electric. The gas goes +/- 60 mph, the FE version has been clocked over 80 mph and I have not maxed that out yet. FE/Lipos are faster, no question about it.

 

[Don Ferrette]

Since the batteries are mostly plastic (lithium POLYMER) I still don't believe the fire was more than plastic burning.

You can believe what you want to, I'll believe what I saw as I was there. The boat blew over on a hi speed pass and smacked down on the water on it's top. The ensuing and rather large quantity of smoke occurred quickly after it hit the water and it lasted for a surprising length of time (the pic Preston posted was towards the tail end of that fire). Again the battery packs, ESC and motor were all submerged so I guess those packs must be constructed with magic plastic that burns under water.

 

[Norm Doerr]

Lohring.. have you seen a lipo fire..
If not and you can spare an old battery.. it might be a good idea to become acquainted with one..

If nothing else you can impress your buddy with one and BTY keep a good class D extinguisher handy.

And by all means.. do it outside on the dirt. It will make some nasty looking marks in your driveway.

Grim

LIPO SACK TESTING IS FUN!!!

WOW! I have seen some things in my day. Doing it in the dirt...marks in the driveway, fires.... Sack Testing Sounds like one heck of a good time...But is it street legal???

 

[Bill-SOCAL]

An electric, non Lipo, actually has the fastest recorded speed of 140mph. But it is a lot to risk. And it takes a looooooong time to charge the big packs.

First, properly handled lipos are no more risky than most other battery types. The risk comes from improper charging or storage.

As far as charge times my 10S 6,000 mAh packs charge just as fast as my 2S 730 mAh packs. Just about an hour. 1C is 1C. The rub comes when using multiple pack set ups. My mono runs 10S2p and takes 4 packs to do it. So I have two chargers that can each charge two packs, and I can then charge the 10S2P 12,000 mAh set up in 1 hour.

 

[Rigged]

lots of videos on youtube showing what lipo fires are like.

I dont have big enormous packs, but i am still scared to death everytime i put my 7.4v 1650mah packs and my 11.1v 2800mah pack on charge, constantly checking to make sure they havent puffed (and i put them in a ammo box). Something just always in the back of my mind that something could go wrong with the charger and start charging them on the wrong settings.

 

[Mark Bullard]

Here is a motor that has failed. It shows the damage that voltage and a short can cause or what 480vac can cause. This motor is 250hp @ 1200 rpm which makes it a 6 pole motor. It has 90 slots that is wound with 5 coil to the groups for 6 groups per phase for a total of 18 groups for all three phases.







After it was rewound and repaired.

 

[Chuck Carpenter]

This all sounds like a riot to me, 1500.00 worth of batteries that can, kill you, i heard from a guy, when our club, the performance model boat club, held the internats acouple of years ago, that these things never blow up, i was on the takedown group, after the internats, in one of the trash cans, i saw a couple of his blowup proof, very expensive battery packs, looked like shrapnel to me, THESE THINGS ARE VERY DANGEROUS, DO NOT EVER KID YOURSELF INTO BELEIVING THEY ARE NOT, Thank You i will stick, with my gas and nitro boats, THEY ARE A LOT SAFER,

Chuck Carpenter :unsure: :unsure: :unsure: :unsure:

 

[HendricX]

1200us$ worth of Lipo's is peanuts ... realy ,

there are such things as 96 x Kokam 5000 ( 12S8P )

Value in us$ : 132x55 euro=7260€ is around 10.000us$

Take a look for yourself : German-building page

 

[Preston_Hall]

Mark,

Don't you know that is only heat shrink tubing. Clean it off and plug it back in. :lol:

 

[Don Ferrette]

A 20 second clip Steve Speas shot during last minute or so of "smoke in the water"-

http://s199.photobucket.com/albums/aa210/i...nt=100_0623.flv

BTW- you can hear what mother nature was dishing up wind wise for that weekend.

 

[Preston_Hall]

Since the batteries are mostly plastic (lithium POLYMER) I still don't believe the fire was more than plastic burning. Hydrocarbon fires can be very persistent. This sounds like a case of improper battery use, not defective batteries. I have run boats with 42 - six cell packs and had no problems with the batteries. We had 900 amp current draws (130 amps per 4500 mah pack) and the batteries never got beyond warm. We used standard model charging techniques and warmed the packs before runs. Lithium polymer batteries are probably safer than gasoline, which stores a lot more energy in the same volume. The safety issues are different, but just as important.
Lohring Miller

Go look at the pics. Do you see all that brown "sand" looking stuff? Is that where the heat shrink blew up all over the inside or is it the guts of the battery? I know what plastic smells like and that was not plastic.

We can agrue it all day if you want. Or better yet, you can start your own thread.

 

[Mark Bullard]

Mark,Don't you know that is only heat shrink tubing. Clean it off and plug it back in. :lol:

Like I said, these things runs on smoke and this motor had to have new smoke put in it.

 

[Scott Norris]

Who said Nitro is dead?

 

[photohoward1]

This all sounds like a riot to me, 1500.00 worth of batteries that can, kill you, i heard from a guy, when our club, the performance model boat club, held the internats acouple of years ago, that these things never blow up, i was on the takedown group, after the internats, in one of the trash cans, i saw a couple of his blowup proof, very expensive battery packs, looked like shrapnel to me, THESE THINGS ARE VERY DANGEROUS, DO NOT EVER KID YOURSELF INTO BELEIVING THEY ARE NOT, Thank You i will stick, with my gas and nitro boats, THEY ARE A LOT SAFER,
Chuck Carpenter :unsure: :unsure: :unsure: :unsure:

I thought you were my friend Chuck. The cells you saw burned were abused on purpose. They were toast so we decided to put a nail through them. Lipos can be dangerous when misused.. But I will put a 4S OPC against any nitro for reliability and speed. Cost is about the same too. When you get to the High cell count boats they are very pricey. Gas is much cheaper.

Too bad I won't be seeing you in Seville any more. I will be at the Pond Hoppers though.

 

[Mike McKnight]

Funny there was a thread on the FE board about LiPo safety a couple of years ago and I seem to remember warning of the dangers of these batteries. There is always a potential for danger whether misused or not. Obviously misuse increases the danger but, you would be surprised by the numbers of failures where no misuse or incorrect handling was detected. In 10 years as a HazMat Specialist in the fire department I saw over a hundred such failures. From laptops and wireless devices to RC batteries. Some causing major property damage. The reason they are so difficult to extinguish is because Lithium is an exotic alkali metal that liberates its own oxidizer as it burns so you cannot remove the oxygen and put it out because it is part of the chemical matrix. It is soft and has a low melting point and is always highly reactive. When you add the polymer compound, which is a complex hydrocarbon like plastic, then you add the danger of over expansion due to heat and toxic fumes.

I could go totally Geek Squad on you and describe the actual combustion process but I don't think I need to given the pics and video that has been posted all over. Just know the dangers of using these little chemical grenades. You want to see something really cool...shoot some water on one of these things when it is burning. HUGE flash as it uses the oxygen in the water and accelerates. We did it once in a training and it was wild. So now lets put them in a boat....wow! What is even more scary is that now guys are using them for Rx power supply in boats with gas or nitro and methanol.

 

[sailr]

The boat blew off the water at a very high speed. When it hit, one of the lipos was ruptured, causing it to ignite and then it caught the rest of it on fire. It was not the fault of the owner/driver of the boat. All precautions were taken when charging, etc. This is a very experienced FE boater.

" Thermal event" I like that.

Lithium+H2O=Oh my God!!!

Lithium+ too much heat= Gee, I didn't think it would blow the door off that oven!!!

As long as the cells do not rupture or overheat they should be ok.

Glenn

Pretty sure they ruptured after the blow over.

 

[sailr]

Good comment Grim. The guys still lugging the big ole NiMh packs around have apparently never seen one them explode either! haha.

Terry,
I will bring my UL-1 to mendota.. we will chat lipos at the race...

its an eye opener.. dont close them out.. they are wonderfull...

ROCK ON!

Grim

 

[lohring]

I stand corrected. However, this still isn't a metal fire.

Lohring Miller

The cause of many fires has been attributed to Lithium batteries and there is a fear of Lithium because of its well known vigorous reaction with water. Under normal circumstances, most (but not all) batteries do not contain any free Lithium. The Lithium content is combined into other compounds which do not react with water. The amount of Lithium deposited during the Lithium plating when cells are damaged as described above is very small and not usually responsible for the fires which have occurred. Furthermore, many of the reported fires are due to burning electrolyte rather than the Lithium compounds.

The guilty party

Although investigation has shown that some Lithium fires are due to internal short circuits as described above, many, if not most fires are caused by abuse by the user. This may be "deliberate or negligent" abuse such as overcharging or operating in a high temperature environment or physical damage due to mishandling, but quite often it is unconscious abuse. Surprisingly many of the most serious fires have been initiated by inadvertent short circuits caused by careless disposal of cells in the rubbish. While strict regulations for transporting Lithium batteries by air have been implemented, the sources of several aircraft / transport fires have been identified as spare laptop batteries being carried in passenger luggage shorting against other items packed with them.

Note: Large batteries such as those used in automotive applications usually incorporate short circuit protection, but smaller laptop batteries do not usually have this facility.

• Thermal runaway

Several stages are involved in the build up to thermal runaway and each one results in progressively more permanenet damage to the cell.

• The first stage is the breakdown of the thin passivating SEI layer on the anode, due to overheating or physical penetration. The initial overheating may be caused by excessive currents, overcharging or high external ambient temperature.The breakdown of the SEI layer starts at the relatively low temperature of 80ºC and once this layer is breached the electrolyte reacts with the carbon anode just as it did during the formation process but at a higher, uncontrolled, temperature. This is an exothermal reaction which drives the temperature up still further.

(Lithium Titanate anodes do not depend on an SEI layer and hence can be used at higher rates.)

• As the temperature builds up, heat from anode reaction causes the breakdown of the organic solvents used in the electrolyte releasing flammable hydrocarbon gases (Ethane, Methane and others) but no Oxygen. This typically starts at 110 ºC but with some electrolytes it can be as as low as 70ºC. The gas generation due to the breakdown of the electrolyte causes pressure to build up inside the cell. Although the temperature increases to beyond the flashpoint of the gases released by the electrolyte the gases do not burn because there is no free Oxygen in the cell to sustain a fire.

The cells are normally fitted with a safety vent which allows the controlled release of the gases to relieve the internal pressure in the cell avoiding the possibility of an uncontrolled rupture of the cell - otherwise known as an explosion or more euphemistically "rapid disassembly" of the cell. Once the hot gases are released to the atmosphere they can of course burn in the air.

• At around 135 ºC the polymer separator melts, allowing the short circuits between the electrodes.

• Eventually heat from the electrolyte breakdown causes breakdown of the metal oxide cathode material releasing Oxygen which enables burning of both the electrolyte and the gases inside the cell.

The breakdown of the cathode is also highly exothermic sending the temperature and pressure even higher. The cathode breakdown starts at around 200 ºC for Lithium Cobalt Oxide cells but at higher temperatures for other cathode chemistries.

By this time the pressure is also extremely high and it's time to run for the door.

 

[shadow]

A 20 second clip Steve Speas shot during last minute or so of "smoke in the water"-http://s199.photobucket.com/albums/aa210/i...nt=100_0623.flv

BTW- you can hear what mother nature was dishing up wind wise for that weekend.

And that's why I run Nitro!

Cliff