DrScoles

My Feedback: (18)

A hand full of us have experienced lipo fires. In my case, I followed all the rules and destroyed a fire safe and almost burned my house down. I have two kids and the new nursery is directly above my shop.

A long time ago, I read about people filling garbage bags full of sand and suspending them above the charging batteries. We use salt water to kill lipos before disposal. There are garage fire suppression systems that have the chemicals that treat the ABC's.

I plan to build a metal enclosure with a water proof basin. My dad is a retired metal shop teacher, we have a full fabrication shop at home. My question is, is it better to submerge the batteries in water if they go off, or have one of these fire extinguishers above it. My fear is that the fire extinguisher won't last long enough to put the lipo out, they take a while to do their thing. Should I use salt water? It would be easy to suspend a few gallon milk jugs filled with water above the batteries. If there is a significant fire, its going to melt the containers and flood the basin.

To store regular batteries, they would be in a tuppeware container in the bottom of the enclosure. This way, if there was a fire, it wouldn't ruin all the batteries.

This already may exist commercially, love to not have to build it myself.

Your thoughts?

P. Richards

My Feedback: (3)

Get a patent before BVM does lol, you might be on to something. Seems simple enough to make and maybe the
Lipo Manufacturers will sell them with the packs.

P. Richards aka SwatTeam

DrScoles

My Feedback: (18)

LOL, the liability insurance to sell something like this is probably the reason it isn't being sold. I just need something bulletproof to store and charge these things. The safes are a joke. You'd think I would have learned when it happened a few years ago, don't want history to repeat itself.

I think water is the ticket. I am going to do some experimenting with old packs. I'll over charge one and dump it in a bucket of water to see what it does :-) Water is much cheaper than the fire extinguisher too.

lightningmcnulty

My Feedback: (11)

That's a great idea.

I thought fire safes were to protect things inside? even then they only last a short time and lipo fires are really hot.

ravill

My Feedback: (11)

I still like the fire safe idea.

It's not about trying to extinguish the fire, its about containing the fire for long enough to get it away from anything flammable, ie the side of the house, and then extinguish it.

The BBQ idea also sounds pretty good.

DrScoles

My Feedback: (18)

Reading about spontaneous fires scares me. I want something stand alone in my shop that doesn't require moving them. It would be nice to be able to charge without hovering over them. My time in the shop is limited with two small kids. I've posted the pics of the fire safe that got cooked here on RCU before, can't find them to repost. Scary how a tiny little pack just destroyed it.

Grainger has some enclosures that would work well, but I think I'm gonna make my own.

Paul0088

http://www.graupner.de/en/products/c...tcategory.aspx

you need this it's made for the job

LiPo safety cases are fireproof containers designed for the safe storage, charging, and transport of lithium-polymer cells
LiPo safety cases are manufactured in accordance with the F30/R30 class hazard regulations of DIN 4102/EN13501
Integral flame-proof pressure valve prevents the escape of hot gas if a fire should start inside the case
Temperature-resistant filter lid prevents the escape of hazardous residues (soot) if a battery fire starts
Foamed glass shell insulation guarantees physical stability of the case up to temperatures of 1200°C
Temperature transfer protection with quadruple safety measures to prevent ambient fires
Integral cable set for connecting external charger toLiPo cells

lightningmcnulty

My Feedback: (11)

not to mention that its not just during the charging time that these things are volatile.

lrb75

My Feedback: (12)

Don't use salt water to dispose of lipos! It doesn't work. Discharge to zero and toss in the trash. Salt water corrodes the tabs off leaving a charged battery.

[email protected]

My Feedback: (1)

if everyone is afraid of lipos why buy them then there wont be any trouble

gooseF22

I was in a buddys shop a few years ago, and he had a plastic grate suspended over a steel bucket of water to charge on.. I am not sure, but I would think it would burn right thru and drop in the bucket.. I might test one sometime to see.. gotta find a plastic grate thats not too thick.. something like this..

JackD

My Feedback: (4)

From what I understand, Water does not extinguish lipo fires. Sand is a better bet I think

I charge and store my lipos in my fireplace (which I dont use of course )

your other option, much simple than the system you are designing is to get a big, thick and deep clay pot. You might want to open a hole for the cables so you can charge inside of it

I think the name of the game is containing the fire, not extinguishing it

r.geisman

My Feedback: (33)

Hi Guys, FWIW--- After reading the threads on this problem, I went to my local home center and bought two metal garbage cans with lids. One is the largest they sell and the other one nests inside of the larger, with about an inch and a half of space between them. I then filled the space between the cans, including the bottoms, with sand (about 80 lbs.). In this configuration, both lids then go on perfectly. As of now, I have this setup in an outdoor shed resting on the bluestone gravel floor. The shed has electric outlets, lights, windows and a large shelf next to the cans for a charger(s). This should work well and safely for me during most of the year. During the cold months, however, I think I'll have to duplicate this setup in my basement, because where I live, here in the Catskill Mountains of NY, it goes well below zero a lot. Again---FWIW. Bob G.

glazier808

My Feedback: (1)

Dr. Your idea is a sound one that has been around for a long time. They used to put barrels of water in ships holds, with a stick of TNT suspended inside in a sealed container. They then ran the fuse out the top and down the side. Any fire lit the fuse, which then lit the TNT and blew the barrel of water up.

Fire out lol.

Casey

Dreddi

My Feedback: (3)

The use of water as an extinguishing agent on a lithium fire is flawed. Lithium is extremely reactive with water and does nothing but accelerate the reaction. If you expose enough to water it will cause an explosion. Lithium also burns so hot that it will strip the water molecules appart adding oxygen and hydrogen to the fire. The best thing a hobbiest can do is allow the fire to burn itself out and hopefully in a safe location away from anything else flammable. DRY sand can also be used to smother the fire and limit the amount of oxygen that can reach the metal, slowing the reaction. The sand also acts as a medium to remove heat.

Chris Nicastro

My Feedback: (3)

No! Dont use water at all!
Water will only augment the lipo chemical reaction. You must snuff the fire out with CO2 or sand.

The truth about LiPos is that provided they are manufactured correctly the typical and most common failure is related to human error.
Not matching up the charge profile with the chemistry, voltage, capacity, or over charging, over heating or poor solder joints. These are all contributing factors and any can lead to fires or just damage to the battery pack.

When I was involved with LiPo's professionally we sold millions of $ in battery packs and the failure rate from production is very low, less than 1%. BUT the customer service side product return failure rate was huge!
I tested all the packs and created failures on purpose with all kinds of packs. You cant believe how hard it is to make a pack self destruct. You have a lot of warning time and signals before the flames come out. Dead shorting a fully charged pack usually results in blowing off the tabs or melting a soldered plug but not blowing a pack up.

Anyway, sorry to say, in my experience every fire I have seen from a pack is the result of human error. Thats different from a failure in use because there is a whole other conversation on that topic.

Also use a steel box to store and charge LiPo packs but in reality any battery pack. I designed and tested a box specifically for this application. The result was a box with ventilation that would allow the pack to expand, react and blow out the air in the box to snuff itself out. Then the hot copper foil sheets and other materials will smolder for a while still very hot. Now you can pour some water on the pack if you wish because the lithium and other battery chemicals have burned away.

PaulD

My Feedback: (39)

Does oxygen even factor in to a lipo fire? I thought lipo fires were a chemical reaction/ runaway condition? Don't think oxygen starvation or water have any effect at all. If you read the reports on the 787 battery pack that lit up at the gate, the fire dept who went in and tried to put the fire out said they had trouble as their conventional methods weren't working.

It sounds like sand works to at least contain the heat created by the reaction. Water likely only cools it down.

Sounds to me like the only safe solution is to keep them away from structures. The scary part is the scenario where you charge your batteries safely, throw them into the car and head for the field only to have them go off long after they're removed from the charger. Think Dave Searles lost his rv this way.

PaulD

mauryr

http://www.skybrary.aero/index.php/P...Crew_Checklist

Bottom line, it's not the "pack" that ignites, it's one of the cells. When one of the cells ignites, it heats up the others which, one by one, will ignite and cause more fire.
Water (or any other non-inflammable liquit) prevents this by cooling down the pack. The ignited cell will run its course and stop burning by itself. Fire extinguishers probably won't do much to put the fire out, what matters is to keep the other cells cool and prevent the fire from spreading while the ignited cells run their course. At least that's what I gather from the article

LCM

I am building a shelf unit with one shelf surrounded by cement board. The bottom also covered with ceramic tile. Haven't tested it yet, but I think that it should contain fire.

bri6672

My Feedback: (6)

As far as the water subject, when my packs are ready to be retired I place them in a bucket of salt water and then puncture each cell one by one. The punctured cell will burn under water for a good period of time so water does not put it out but contains it. Human error is the biggest problem. I use the ammo box method with a few holes drilled in the top for ventilation. They are in my garage sitting on concrete away from any flammable material. It a box goes up the hope is it will be limited to the box and a few feet around it which is just concrete floor.

I would love to hear more about the fire safe failure story was it sitting against something flammable?? What size pack or packs were involved??

Chris Nicastro

My Feedback: (3)

That will handle the heat from a fire but you want to have ventilation in that area. The smoke and fumes from a battery fire are very toxic.

Lithium reacts with the air once exposed and that is why there are flames. If the box or device allows the chemical reaction to vent out but not allow fresh air in then the event is less aggressive. The box I made has vents and baffles to block flames from jetting out. I destroyed about 12 battery packs in one test with out any damage to surrounding flammable materials.

Another consideration is the fact that any LiPo pack expands as it fails so you have to account for the increase in area it takes up. Otherwise the container could become part of the problem.

DrScoles

My Feedback: (18)

what do you guys think about this? It already has cutout on side for wires to enter and is self closing. Room to suspend sand from above, seems like if I could seal the area where wires go in, its air tight.

Ron101

My Feedback: (22)

I have all my lipos in storage charge, placed in lipos bags, which are placed in foam lined ammo cans....

We have a sprinkler system in the garage but I still would like them out of the shop. The problem is my shed (out building) gets very hot in the summer, not really worried about the cold here in california and lipos can be frozen (just must be thawed to use) around here in my shed it will never drop below 40 inside that shed.

But we can hit 110 for days on end and it will be even hotter in the shed,

So my plan is to place all four of my ammo cans in a small mini fridge.
like this: http://www.homedepot.com/p/IGLOO-3-2...8?N=5yc1vZc4mo

Then use and external controller to keep the temp at maybe 68 degrees with a unit like this: http://www.amazon.com/Elitech-All-Pu...mostat+plug+in

here is a how to on how to setup a fridge like this on you tube: https://www.youtube.com/watch?v=-5ZW2XScrzI

I'll just run a cord out to the shed and the lipos are out of the house and setting at a perfect storage temp
I keep putting it off but need to get on it

Chris Nicastro

My Feedback: (3)

that cabinet would be fine but I wouldn't bother with the sand except in a 5gal bucket on the side. Making it air tight is also not necessary because you want the change in pressure to expand outward. The fire is usually very aggressive and very hot so it will consume oxygen very quickly. The trick is for the fire to consume the air in the space faster than fresh air can come back inside. This will snuff itself out for the most part and then your left with the hot copper foil sheets from each cell. Since the cabinet material is steel then I wouldnt worry about heat transfer as much. The Venom Stronghold charger and box I designed are made from duraluminum with a polycarbonate window. One box withstood multiple cycles without fail.

GSR

My Feedback: (145)

Pick up an old toaster oven. Set it on a piece of hardiboard somewhere with about 12 inches clearance. S