LI-po battery safety

[danemotty]

I'm sure you guys have heard this already but in case you haven't Lipo, or LI-Ion batteries have a very high power density which makes them small and powerful, but they have a nasty habit of catching fire when being recharged, as a model airplane flyer we have them catch fire more often that average as physical damage is one thing that may cause them to go off, so I have learned the hard way, they burn like a magnesieum flare, really hot. It's prudent to charge your batteries in a fireproof container of some kind, ceramic flower pots and corning ware comes to mind for smaller batteries, airplane hobby shops even sell some kind of fire proof plastic bag. when travelling, the bathtub if it's an old fashioned ceramic one is a good place.
Just don't trust the things, even the ones in your cell phone and your laptop.

Lithium phosphate batteries do not burn and provide the same amount of power/wieght ratio, they use these alot in large model aircraft...hopefully soon we will see them being used in the diving industry to help prevent some of these accidents.

[r4e]

Jill Heinerth posted this video a while back. Her design for an battery charging box/blast shield.

http://www.youtube.com/watch?v=lsqFm4AdpCQ

I like the general idea of Gill's "blast box". However, I would like to have something more portable for my "small" 300Wh LiPo battery that came with a 200W HMI.

I wonder if a carriable metal tool box (or ammunition box) would be suitable? I could cover the insides of the tool box with small ceramic bathroom tiling. The idea is not to make the box gas tight, rather, only to delay and contain the fireworks from immediately spreading to surroundings. Similar concept like the LipoSacks, but, which are far too small for my battery. Since LipoSacks work, wouldn't the same concept work in a slightly larger size? Or would the failure of a 300 Wh LiPo battery be unmanageable in a tool box and sending away metallic and ceramic shrapnel?

The toolbox could also be relatively weather proof allowing charging outside, e.g. on top of a boat deck instead of having to charge under deck. I have in mind week-long boat execursions, so I really need to solve this safety issue. The same would apply to cave excursions, if the motels do not have ceramic bathtubs...

Furthermore, I could fill the tool box with some unburnable but soft isolation/dampening material so the box could double as a transportation box when taking the lamp+battery on rougher RIB boat trips.

Perhaps I could even attach a permanent digital volt meter display on the lid of the toolbox for monitoring charge status.

Comments? Am I missing something?

[FW]

Comments? Am I missing something?

Sounds like it would work to me. I just use a cooking pot for my light battery, but it is smaller. Anything to contain the fire will work. Just don't have anything flamable around it, Li batteries spit sparks when they burn.

[CaveMD]

I like all my stuff in one room. So when it goes, it goes big. A house fire? ha. When mine goes it will take out half the block at least. The family fire plan is to run like hell as fast and as far away as possible. Some family's may plan to meet in the yard, or across the street in the neighbor's yard, but my kids have practiced the run to the hospital three blocks away where the plan is to meet in front of the emergency room entrance! Last one there is a rotten egg! The neighbors have been warned too.

skip

Knowing myself, I will likely have many things in the house just as if not more dangerous in a fire than the dive gear...will probably need the same emergency plan when I have kids one day lol.

[r4e]

I like all my stuff in one room. So when it goes, it goes big. A house fire? ha. When mine goes it will take out half the block at least. The family fire plan is to run like hell as fast and as far away as possible. Some family's may plan to meet in the yard, or across the street in the neighbor's yard, but my kids have practiced the run to the hospital three blocks away where the plan is to meet in front of the emergency room entrance! Last one there is a rotten egg! The neighbors have been warned too.

skip

I am afraid that blasting half a block is too modest. That's why I prefer to load all my O2 tanks and LiPo stuff on my RIB boat in addition to 520 liters/130 gallons of gasoline and then go cruising at 50 knots (55 mph). After hitting an underwater rock or submarine at full speed and flying sky high, it is much more rewarding to swim 100 miles to the closest emergency room. A bit difficult to find dive buddies though. And I dare not take my family with me.

[MORGAN]

Knowing myself, I will likely have many things in the house just as if not more dangerous in a fire than the dive gear...will probably need the same emergency plan when I have kids one day lol.

No problem. Just build a small, secure metal or concrete block building at a safe distance from your house and keep the kids in it.

[FW]

No problem. Just build a secure metal or concrete block building at a safe distance from your house and keep the kids in it.

[MichaelAngelo]

No problem. Just build a small, secure metal or concrete block building at a safe distance from your house and keep the kids in it.

Heres the blast box I built at H2O. Bottom is cement blocks while the top is a HUFFY Steel tool box. Scooters fit in the bottom, cannister light up top. I also wired the power to a 6 hour timer, (similar to the timers for bathroom heat lamps) Now just gotta built the child seats to make your joke be completely true.

[a64pilot]

Forrest,,
To add insult to injury what happened to my new scoot Sun when we dove was almost certainly a bad cell in the battery, of course that is what usually causes a fire during charging too, so I guess dieing in the cave is better than burning the house down.

[gschaut]

How much heat is generated by the battery during the NORMAL charging process?

Do you need to consider ventilation / heat dissipation during charging. Sealing a battery up
in an insulated, airtight container sounds like it "might" present a problem.

That being said, I can vouch from personal experience that plywood is quite fire resistant.
I have had occasion to walk across plywood floors only to find out after-the-fact that
the plywood had direct flame exposure to the underside for several minutes without failing.

Yes, it is flammable. But it will tolerate quite a bit of heat before it fails. Lined with some
fiberglass insulation, a plywood box would be cheap, easy to build in custom size, act as
a shipping container, and suppress quite a bit of flame/shrapnel during a "failure".

just a thought.