building a lipo storage box

izeman

izeman

1 GW
Joined
Jun 21, 2011
Messages
5,131
Location
Vienna, Austria
i know there are some threads about lipo fire, some about storage tips etc...
i'm looking for a solution to store quite a lot of lipo in my basement. i know this should ideally be stored outside in a fire place. but climate here doesn't permit that.
so i thought of ammunition boxes. you can get them used for $20 each here. the ones which are 30x15x18cm (12x6x7in) should hold 10 of those 6s 5000mAh HK lipos.
which definetely is WAY TOO MUCH ;)

i think of something to hold 4 packs to
a) make the energy contained not too much
b) reduce the amount of smoke
c) reduce the amount of heat
d) last but not least reduce the money literally "burnt"
in case of an incident.

so what are your suggestions? can these boxes stand a lipo fire?
would it be better to add pressure release holes or to make them air tight?
 
Just for storage?
Wherever they are inside, you would have smoke to deal with, unless you wanna get fancy with an automatically undamping vent from the enclosure. (fire rated drywall is a good enclosure)

Since most of us charge before we ride anyway, I'd assume they'd be at storage voltage. Is there really any possibility a healthy pack would self discharge to the point of ignition when in storage? Does HK have some special way of warehousing the batts?

Anyway, with my assumptions in mind, I've stored in the crisper drawer of my fridge. An older fridge anyway, but I'm willing to bet it and the food there won't be an issue, plus it's a great temperature for storage and pretty fire resistant. Maybe the extra volume compared to small enclosure would help contain some smoke too?

Also, store right next to the butter for a little zip on the morning toast.
 
well. storage for me is the state the batteries are in whenever i don't ride the bike.
now in winter this is 24x7. and there are a lot of smaller 2s, 3s, 2000-5000mAh packs for quadcopter and rc car. those all are kept at 3.9v all the time. i don't expect them to self ignite, but you never know.
a metal, heat isolated box maybe a good solution for charging the quad's batteries as well.
there also are around 15x 5000 6s packs waiting to be installed ...
your argument regarding HK warehouse is valid. they have TONS of those lying around. but those packs are new, not dented or physically damaged anyhow. of course we all know that new packs may be defect from production, and a pack staying balanced w/o dents and never over/undercharged is very unlikely to go wild, but you never know.
the problem of smoke still exists of course. but a tight fire and smoke dense door to my workshop will help. better to have smoke in the house than a burning house ?!
 
I have opted to put vent holes in the ammo boxes I use. Each box can hold much more, but I limit it to 500wh per box. 14s 10 ah.

The holes face my fireplace, so if fire shoots out the holes it will aim for the tile. But I also don't latch down the tops, in case a lot of fire needs out.

Smoke detector nearby, and a way to get them outside FAST. I really see no way you could get a hot box outside from your basement, at all, let alone fast. My hope is that a smoke out won't affect the entire house so bad if I'm home when it happens. If I'm not, I'm screwed.

My gut reaction is that a basement is a really shitty place to store them. The smoke will fill the entire house. But It's surely possible to make a place fire resistant enough to have one box go up without setting the house on fire. Something along the lines of ammo boxes stored inside an old oven, or a fire resistant closet made of thick layers of fire code sheetrock. The key thing on the boxes is to have the fire limited to one box. Not the entire stash.

But the first layer of defense is sorting the packs. No overly puffed cells, no really old packs, no dinged packs. If they don't stay balanced, they don't come inside. Shitty ones stay out of the house, and are stored in an old fridge.
 
i don't think that the hot gases shooting out of the box will be able to set the house on fire - if they don't touch anything flammable.
the boxes will be masked with fire proof dry wall inside. and the batteries are divided by drywall as well. as seen in one of those videos drywall will NOT heat enough on the outside to start a fire. so it will be hot gas and smoke "only" to deal with.
yes. the basement will be full of smoke, and the smoke will spread inside the house. but only if you open the doors. and there are some doors to seal the workshop from the rest of the house - i hope.
batteries that show signs of wear, or the slightest swelling are disposed immediately.
so 3 ammo cans can house all me lipo. will need some work to make them fireproof. maybe i will test one with an old 6s 5000 zippy and see how it goes.
 
The box with the type x drywall is pretty cool. Individual compartments and venting too.

To do this right, I would do away with portability for inside the house and get one of those special big cabinets for flamables, then I'd vent that sucker outside with a thermistor controlled damper and fan. I've seen those neato cabinets used on craigslist b4. With alot of batteries and in certain non-rural settings this would be ideal imo. You could even compartmentalize the interior with the sheetrock. El cheapo would be an old fridge tho, and imagine a stylish old coke fridge or something- way more art decor than an industrial cabinet.

I was thinking about something like this:
stora.jpg
But came across this instead:
stor.jpg
http://reading.craigslist.org/for/5316739470.html
Fire rated filing cabinet vented out would be pretty awesome

Or the other issue not touched on is:
assumption that freezing temps is bad for longterm lipo storage. i thought this was actually beneficial and not damaging in any way? like induced hypothermia for drowning victims or cryogenics the slow rate of chemical/cellular activity is a bonus in safety and longevity? so just store all the longterm stuff outside in an old fridge and have an even further reduced possibility of any spontaneous combustions?
 
Got a pilot light for a furnace or water heater in that basement?

The hot gasses vented from a Lipo are highly volatile. Lipo themselves don't actually "explode" but the gasses they vent can explode if contained and then ignited. Most of the lipo fires you see on youtube are of packs burning as they vent, which is a best case scenario for a lipo fire. The gas can escape, there's no pressure build up, there is a large volume of air to vent into. Even Slightly contain those gasses and you get different results.



I know I've posted this a few times before, but this is one 5000ma cell, bursting in a semi contained space.
[youtube]NzUla1udKuA[/youtube]


That answer is to contain and vent the gasses in something sturdy enough to take a sudden low pressure explosion. A fireplace is ideal, but you can build a metal box with a chimney vent to the outside that should be safe. If it's fireproof enough that you could build a 3 log fire in it and let it burn overnight unattended, it should be safe enough for lipo.
 
Yeah, short of a hood that will actually vent the smoke and volatile fumes outside, nothing much is going to help with the whole house getting smoked. You might think your cellar door is tight, but I disagree. I dismantled enough burnt houses in my day, and smoke goes everywhere, somehow. I never solved this myself either, but soon my lipo stash will be pretty small, and all kept outside. I'm slowly converting to 18650 stuff, which still could burn my house down, but the chances get less than lipo. (having a bms for one thing)

But again, the key thing here is limiting its quantity, having it all stored in smaller amounts so you don't have 1500wh going up at once. The cleanup from 400wh much better than the whole stash.

And to beat the dead horse, never ever any suspect shit in the house. No puffies, stinkers, dingers.
 
That's good to know- I wanna look into that more because other chemistries don't seem to mind? (Leadacid, alkaline, nimh, nicad)

Found this: According to one book, lithium ion batteries should not be frozen. Note that most lithium-ion battery electrolytes freeze at approximately −40 °C, which is much colder than the lowest temperature reached by most household freezers.

Both can be right, can't be frozen, but freezing takes place low enough to be a non-issue for most. Note capacity loss over time decreases along with temperature. I would assume this to be the case right down to it's freezing limit. Minimalized negative impacts are assuming charging and discharging done above 0c (imo 50-60f min), and batteries are stored at storage voltages.

Some good links: https://www.google.com/#q=can+lithium+batteries+be+frozen

I think there was also a thread on here with testing lithum down to at least 0c?
 
Unless some people have contradicting information to offer, I then would actually feel safest with outdoor storage with even a benefit to battery life. Likely there is a drasticly reduced possibility for offgassing, self discharge, and/or fire as well.
That in mind, if at all possible, a semi sunken appliance, cabinet, container, would help equalize very high or low temps with the ground helping in the worst winter and maybe summer too. I'm picturing a fridge 80% buried while facing up. Maybe a minifridge?
 
Unburied old fridge, outside, is where I kept my suspect stuff. And all of it, in winter.
 
dogman dan said:
Unburied old fridge, outside, is where I kept my suspect stuff. And all of it, in winter.
Click to expand...
i guess "winter" in arizona is not really the same as in austria. :) just as low as freezing water and (almost) no snow, compared to -20C and meters of snow ...
i did some research, and as always there are TONS of hear say semi-knowledge. like "i heard that someone ..", "i once had a lipo on the balcony ...". so no real scientific research stuff when lipo chemistry starts to freeze. but i could be at -20C. and if you put those packs in a vented, isolated ammo in the garden hut they should survive -20c OUTSIDE. what do you think? if course they are storage charged, and will NOT be used at that temperature. they lay there until it is spring again. maybe voltage checked once in a while.
 
I use a safe box for storage
YB-350A-M-500x500.png
 
did you do any real-life test with it? does it have venting holes?
what happens if one pack/cell vents? heat builds up internally and ALL cells will go up. a lot of gas.
can the safe stand this pressure? is it gas leak proof?
sorry for the dumb questions, but i want to be 100% sure before i buy/build something.
 
izeman said:
did you do any real-life test with it? does it have venting holes?
what happens if one pack/cell vents? heat builds up internally and ALL cells will go up. a lot of gas.
can the safe stand this pressure? is it gas leak proof?
sorry for the dumb questions, but i want to be 100% sure before i buy/build something.
Click to expand...

Have not done real-life test but it is thick steel that it is not going to burn on top of some bricks just in case it heats up a lot.

It has 3 holes on top just in case preasure is a problem cause now i have a spare fireplace were i can put the box... but i did some tests with big firecracker before with no issues.

Anyway i am moving to 18650 cells now in my builds.
 
Likely the very safest, would be something that would perform exactly like a wood burning stove in the basement. Thick enough steel, and a large vent or flue that would conduct the heat and smoke outside if an event was to happen. So a metal tool locker, and some six inch wood stove chimney pipe?

http://www.toolboxes4less.com/jobox-heavy-duty-welder-s-box-and-small-chests.html#.Vnk5Av9Ih2s

Or something similar, but built from fire resistant materials, like the cement type siding board or brick. The key thing really, is venting the hot gasses out of the house by a chimney flue.

I'm assuming your family is sleeping above this, so the price to keep them safe could be pretty high, and still well worth it.
 
BBQ grill sitting away from anything flammable works for my RC Lipo storage needs.

More or less contains flames and allows for venting pressure which is main criteria.

Garage, shed or indoors? Smoke alarm, smoke alarm, smoke alarm....
 
adding a vent/chimney in the basement is next to impossible. this is steel reinforced concrete. no easy job. and if i did my wife would be threatened to death. if i build such a thing just to store the batteries, then they must be SUPER dangerous. no more sleep for her :)
i will store them in the garden shed in ammo boxes. that should work. i could even think of heating them in case temps fall below 0C. heating costs should be minimal.
 
Good plan. It's not that the risk is so high, especially if you sorted out the obviously damaged packs. It's that the risk to family needs to be close to zero as possible.

Gently warm your storage area with a reptile heater, or something as simple as an incandescent light bulb on a timer.
 
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