best fireproof case/ system or DIY to store/charge lipo liion safest way

HI
for ebike battery pack like 1000 wathours energy which is normal size battery for ebike
I spend lots of time reacherching and it is unclear, lets help each other

1first option is ammunition metal case with seals out(to prevent pressure buiding up explosion) .
THe videos i saw show this was letting so much smoke out. also somethimes fire comes out or the sides and they seem to use small batterys for flying plane and in our case our battery packs are much bigger. see https://www.youtube.com/watch?v=CnNId0mDnBo

2 second options is the bat safe xl. it is difficult to know if it is 500 or 110 wh since they write both . i a video it was terrible when the guy put a bigger battery than bat safe limits and it burned like hell around.

3 there are people that use ciment blocks but i fell like fire would come out of the jonctions.

4 some use a auto sand drop system which is wise but difficult to build. seems intelligent https://www.youtube.com/watch?v=s0kzuEpyNyQ

5 bags dont seem to be an options.

does some one know the wh of test no 4 in the video (best method if someone chooses ammo box)


what do you think, what is your experience?

Suspend your charging battery pack in a plastic carry bag above a large water butt ...( bath, trash can, 44 gal drum, etc).
Use a long charge cable to keep your valuable charger remote from the pack.
Fix a smoke detector/alarm above the “charge bag” to provide warning of any imminent “thermal event”
If the pack overheats and flames, it will melt the thin bag, and drop into the plunge bath to self extinguish !
You can refine, improve, trick out, etc this system, but immersion in large volumes of water is the only sure way to contain and snuff out a lipo fire . :wink:
Obviously you can use the same set up, when not charging , for peace of mind , safe, storage :wink:

Hi folks,
I mainly read in this part of the forum, sometimes I shake my head, sometimes I am intrigued by the geniuity of some mechanical solutions and ideas some people have. When I shake my head, I seldom comment. People mostly have to make bad experience themself. Most cant be helped by good advise. A lot of the later even start to critize you on no grounds whatsoever. Only a few people are greatful for your advise and even fewer say so.

I hold an advanced degree in electrical engineering and have also read myself into safety of lithium batteries and this time I have to comment because of what was said, people could be harmed seriously.

I tell you: To use water to extinguish a lithium fire is a very very very bad idea!!!!

Water and lithium react to hydrofluoric acid. An extremly dangerous substance, especially if in form of vapour. It will absorb through skin contact and will penetrade quickly very deep. Inhaling is especialy dangerous.

Water is however used to fight extensive lithium-battery fires. But only by experienced fire fighters. You have to have an unlimited amount of water and the means to disperse the right way. The fire is showered to drag down the vapours to the ground where it quickly loses its dangerous properties. It also cools and therby slows down the reaction. Drownig it with a bit of water will mostly not help. The reaction will continoue for some time. So, Unless your system is designed to have plenty of water for any case, you are certain it will not spill somewhere else, and it will trigger to the right time, you are likely to create very a dangerous environment.

DO NOT USE WATER TO EXTINGUISH A LITHIUM FIRE.

My advise. Throw the battery out the window if possible or out into the open, get far away and call for help.
Yes sand helps too. But only if you apply it at the very beginning of the fire and only for small fires.

Hydrofluoric acid will also stick to surfaces in the room, therefore contaminating them. Depending on the amount, the room will not be safe until properly decontaminated.

DO NOT USE WATER TO EXTINGUISH A LITHIUM FIRE.

My advise. Throw the battery out the window if possible or out into the open, get far away and call for help.
Yes sand helps too. But only if you apply it at the very beginning of the fire and only for small fires.

Hydrofluoric acid will also stick to surfaces in the room, therefore contaminating them. Depending on the amount, the room will not be safe until properly decontaminated.
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HI
i also read water is not a good idea for LI ion.

Peolple rarely talk about fumes but what a mess it can do even if fire is content.
there seems to me soot coming out wich bat safe seems to take care of but what about the toxic fumes you say that needs to me cleaned is there a way to prevent retain them?

the auto sand spiller in the vid below is ingeniuous.

what do you think about simply burring the batterypack inside a large metal toolbox filled with sand even on top of the pack?

Mart76 said:

To use water to extinguish a lithium fire is a very very very bad idea!!!!

Water and lithium react to hydrofluoric acid. An extremly dangerous substance, especially if in form of vapour. It will absorb through skin contact and will penetrade quickly very deep. Inhaling is especialy dangerous.

Water is however used to fight extensive lithium-battery fires. But only by experienced fire fighters. You have to have an unlimited amount of water and the means to disperse the right way. .......
.........you are likely to create very a dangerous environment.

DO NOT USE WATER TO EXTINGUISH A LITHIUM FIRE.

My advise. Throw the battery out the window if possible or out into the open,

Click to expand...

Hi Mart76,
What is worse...a uncontrolled violent fire, ..or a room with “toxic” fumes and a tub of contaminated water ?
we are talking of a disaster management situation , not a waste bin fire.
If you have seen a typical “Ebike size”. (0.5 - 1kWh) lithium battery fire, you will know that “throwing it out the window”, is not a realistic option once it has become an actual flame fire)
You will also know that sand will not “extinguish” a lipo fire,..merely contain some of the flames, it doesnt cool the source either, infact it accellerates the thermal runaway effect from cell to cell..you still end up with a room full of smoke and toxic fumes.
Actually,..i have never seen the effects of sand on an pack of 18650 cells which tend to explode violently much like shotgun cartridges, and i suspect would most likely blast through any reasonable amount of sand (50kg ?) around the room !
The only practical attempt at minimising and controlling a lipo fire is to immerse it in water to remove the heat from the source and minimise thermal runaway.....AND i have seen a large 2kWh 18650 pack fire “controlled” by dunking into a garbage can full of water which rendered it effectively as harmless as a hot tub !
That is why i suggest a LARGE CONTAINER of water to submerge the burning pack...not a spray from a hose of shower tap.
Which ever approach you take you with have a room (if you do this indoors) full of toxic fumes and smoke,...
... but your chances of preventing a major uncontrollable fire are much better if you can contain the flames and extract the heat from the source...sand, foam, gas etc will not do that

lol @ anyone who wants to throw their burning battery out the window.

See what I mean? Some people can be helped.

My intention was to point out that fighting a lithium fire with water is generally a bad idea, especialy for the hobbyist :wink:

Yes drowning out a small lithium fire in a big barral of water works. That is a scenario I described in my post. It only works though, if everything works as intended. Maybe the battery does not fully submerge, the fire is alread too extensive so it will evaporate to much water, and so on...a automaticly triggered "water-system" designed by a hobbyist, might have its flaws.

It is not a choise between poison and desctruction. With water you might get both. First the poisoning of people coming in the room to see what is happening and, after the water is not enough, the desctruction.

In my designs I try to contain the fire with fireproof material and try to prevent a fire with electrical measures. For example, put the battery in a tiled room with the door shut in a place outside where the rain and sun can not reach. The mentioned smokedetector is a very good idea.

Mart76. I read your post. And you are 100% technically correct .....however,..
What i, and most others will take away from your post is..

DO NOT USE WATER TO EXTINGUISH A LITHIUM FIRE.

Click to expand...

Which is unhelpful advice for someone facing a flaming battery pack or planning a safe charge/storage system.
A few kg of sand in a box wont cut it..even if you are prepared to burry your packs in a sand box for charging or storage every time !.
You have got to kill the heat, and water immersion is the best practical way to do it...which is why fire teams pump water onto lipo fires.
Sure , its not ideal, its messy, likely to result in nasty fumes and liquids, but if the alternative is to lose your garage house and possessions (maybe even your life if you are asleep !) ...then i will take the limited acid fumes over doing nothing.
Obviously a automated system to dunk a overheating /flaming pack into a vat of liquid Nitrogen would be technically better, ....but not practical for most situations.
WATER IS THE MOST EFFECTIVE OPTION. For containing a lipo fire.

@Hillhater

As a general rule for the hobbyist. My advise stands.

For the rest. Why repeating what I wrote just before?


WATER IS NOT THE MOST EFFECTIVE OPTION for containing a lipo fire for a amateur/hobbyist that lacks the equipment and experience to do it.

Mart76 said:

I tell you: To use water to extinguish a lithium fire is a very very very bad idea!!!!

Click to expand...

A lithium metal fire, yes.

But a battery does not have lithium metal in it; it's all in compounds that prevent the problem of further igntion of lithium by water.

Like most people, you're confusing the two.

Water and lithium react to hydrofluoric acid.

Click to expand...

If you are saying that they react to *create* that, it's impossible. There's no fluorine in water or lithium metal to create the acid.

If you mean that they react *with* it, then sure--most things do, because fluorine is the most electronegative element I can recall, and thus it reacts with just about anything else (I think argon, helium, and maybe krypton are the only stuff it won't react with).

Mostly one will find electrolyte containing LiPF6 in a lithium battery. That is where the fluorine comes from.

Mart76 said:

@Hillhater
As a general rule for the hobbyist. My advise stands.

Click to expand...

Your advice being what exactly ?
...toss the burning pack out of the window ?
...leave it to burn and call for help ?

Mart76 said:

WATER IS NOT THE MOST EFFECTIVE OPTION for containing a lipo fire for a amateur/hobbyist that lacks the equipment and experience to do it.

Click to expand...

...Which is why i suggested a simple, practical, safe, way for an amateur/ hobbyist to use water to prevent a lipo fire from turning into a major disaster.
Some relevent background reading..
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5577247/#!po=18.7500

Probably the safest bet, besides just charging outside, would be to buy a battery potted in epoxy with a fiberglass reinforced case.

https://www.youtube.com/watch?v=oBlac5gWLfI
https://www.ebikes.ca/product-info/ligo-batteries.html

Or maybe this guy:
https://lunacycle.com/luna-wolf-v2-52v-battery-pack/

fused cells + potted

As far as enclosures: Probably steel cabinet. They make specifically 'flammable safety cabinets' for housing chemicals for labs and such things. Kind of expensive, though.

The Ligo battery is just 100 Wh..most Ebike packs are 5-10 time bigger with corresponding more energy.
..a discharge “short” test is not the same as an overcharge / BMS failure . After 2 mins @ 50A discharge that pack is more than 50% energy depleted. So less than 50 Wh energy left
With a “overcharge” fire the thermal runaway starts with the full pack energy to dissipate, . On a typical 1.0 kWh pack , that would be 20 times as much energy to release !,
Cell fusing is not a solution ,
Potting / casing of large packs is likely to result in a serious explosion risk, and will certainly produce a very heavy pack....not desireable for an Ebike !
The best solution is quality cells, quality design and construction, quality BMS with multiple thermal monitoring points,.....and quality charging equipment.

Cell fusing is not a solution ,

Click to expand...

Of course it's a solution to something. What you think it's not a solution to is a bit of a mystery to me. It disconnects a cell when it becomes internally shorted. That way the pack doesn't try to discharge through the bad cell.

The Ligo battery is just 100 Wh..most Ebike packs are 5-10 time bigger with corresponding more energy.

Click to expand...

They are designed to wire together in parallel so you can have LiGO be whatever wh you want. One of the advantages to having separate hardened batteries is that heat doesn't spread as readily between different parts of battery, thus limiting the potential for cataclysmic fire.

..a discharge “short” test is not the same as an overcharge / BMS failure .

Click to expand...

It's not the same as a overcharge, but how many ways can BMS fail that could cause a fire other than causing a short? What do you think the most likely failure mode for BMS failing that could cause a fire that isn't a short?

Potting / casing of large packs is likely to result in a serious explosion risk,

Click to expand...

It's plausible that they could cause am explosion. I don't think 'likely' is an accurate description at all. In the LiGO prototype test the battery vented out the bottom after becoming distorted. Which is exactly what you want.

The solution to this possibility is to test and see what actually happens. After all the same logic can be applied to make a argument as to why LiPo soft-packs are safer then steel-encased 18650s and while plausible it would be unlikely since they are designed to vent from the top, and many are designed to vent additionally from the bottom. The truth can only be discovered through testing and it can be engineered to not be a problem.

I would really like to see the Wolf pack being tested to destruction.

and will certainly produce a very heavy pack....not desireable for an Ebike !

Click to expand...

Lunacycle claims their 14s4p wolf pack weighs 9 pounds. Em3ev claims their 14s4p 'super shark' battery weighs 9 pounds.
The weight seems negligible.

does any one knows what filter could filter the toxic fumes ? maybe if added on the outside of an ammo case it could be a solution?

Charging your fireplace or charge in a barbecue outside. Fireman use water on battery fires but then again they're all suited up and they got a safety Shield over their face etc etc.

Sleepy T,
Individual cell fusing will not prevent cell overheating/failure from overcharging (BMS/ Charger failure)
And we have had many incidents resulting from failure due to charger problems.
The Ligo packs are a compromise to meet air travel regs.... but they still can act as an ignition source if near any other materials.
Put a number of them (4, - 5, ?) together in an enclosure for an Ebike and then see how that test goes ?
You will still have flame & smoke to deal with.

It is physically impossible for two similar packs with the same number of cells, to weigh the same if one is fully “potted”
Some Tesla packs are built with individually fused cells, and “fire suppresant” material sprayed onto the finished assembly..
...but.it doesnt stop thermal runaway once the pack lights up.
Even YUASA and Boeing couldnt engineer a pack to be “fire safe”... they had to settle for fume and flame containment and venting to outside the aircraft.

It just not is what burned up in the fire but your fiberglass and graphite things that are 5-6 ft away that melt and the greasy black suit of smoke that covers everything and is almost impossible to remove. This is the damage from a fire

I really don't see any possibility to eliminate smoke damage. Not unless you are using something that is sealed completely or is vented to the outdoors. If I was running a business I would want to invest in a heavy steel cabinets, but for home gamer I don't see that being likely.

The best you can hope for is to prevent the fire from spreading.

sleepy_tired said:

I really don't see any possibility to eliminate smoke damage. Not unless you are using something that is sealed completely or is vented to the outdoors. .....

Click to expand...

I was thinking exactly the same, then i came across this ...
https://youtu.be/4vbsIvwSBpI
[youtube]4vbsIvwSBpI[/youtube]

That thing is going to be billion and a half dollars, though.

hum
someone said that dropped in water it would not smoke exact? how many times the volume of the battery pack does it need to be dropped in ?
Would a 400wh pack suspended in the higher part of an ammo case filled with water under be enough?

i build bigger batteries usually with a strong alu case with a alu tape vent hole that can blow out in case of overpresiure or fire and direct the flames to the ground or a direction where it cant damage other things. the same principle is used with storing gases like propane or LPG in cars where the blowoff valve is directed to the bottom of the car by a hose.

trying to stop a lithium fire is basically impossible. just let it burn but let it burn in a controlled manner that gives enough time for people to get away. that is all you need to do. once people are gone you can just let it burn.