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Wow. And you can park a car that has a battery with 5x the potential energy in my garage without any additional requirements? Somewhere or another the code does
by ipython 2y ago
Wow. And you can park a car that has a battery with 5x the potential energy in my garage without any additional requirements? Somewhere or another the code doesn’t add up.
- trhway 2y agoTypically the code requires 60-min firewalling of the garage.
- floatrock 2y agoFor an EV? I think the op is pointing out that some building codes put huge restrictions on building isolation with stationary storage like powerwalls, but as soon as those batteries are on wheels then regulating cars is someone else's department.
- trhway 2y ago>For an EV? For a 20 gallon tank of gasoline on wheels.
- ipython 2y agoAlso a good point. If each gallon of gasoline is equivalent to about 33kWh of energy, I could have 1.3MWh stored in two ICE powered cars. I guess it’s harder to put out a battery fire than a gas fire?
- Etheryte 2y agoThe way you put out a battery fire is you don't. Last I checked, the current best practice for an electric car that catches fire is to just let it burn to the ground while trying to stop anything around from catching fire.
- mschuster91 2y agoNot an option in the basement of a building, the temperature will risk structural integrity.
- themaninthedark 2y agoNot to be callous but the "just let it burn to the ground while trying to stop anything around from catching fire." might be the structure over the basement in this case and the keeping other things from burning would be the surrounding buildings.
- bigfatkitten 2y agoIf firefighters can't access the basement safely, that's exactly what they'll do. They'll protect the exposures instead, ie the neighbouring buildings.
- trhway 2y agoA car itself contains a lot of stuff to burn (tires for example, etc) - look at any burnt out car - it is just a metal shell (until it was an aluminum one). So, i hardly see much difference between ICE and EV here.
- sidewndr46 2y agoThe difference is you can extinguish a fuel fire by smothering it. Deny it oxygen and it can't combust. When you do that with a battery fire, it just flares back up as soon you stop smothering it
- trhway 2y agoIn theory you're right. On practice - until you're an equipped firefighter, you wouldn't be able to do anything once a regular car develops significant fire.
- sidewndr46 2y agoYou can absolutely extinguish a fuel fire early on if the tank has not ruptured. Sand, baking soda, water, dirt, blankets, all work. If the battery on an EV develops an entire short you are not extinguishing it. If it were available, the safest mechanism would be to push it into a hole and bury it
- kelnos 2y ago> ... until you're an equipped firefighter... If my car catches fire (EV, ICE, whatever), I'm going to call a firefighter immediately, regardless of the severity.
- potato3732842 2y agoEh, a 5lb extinguisher in good hands has enough punch to extinguish a flaming stock tank of diesel twice so it should put out a car that isn't totally engulfed. Source: Got to watch a demonstration put on by the local firefighter training center. Source 2: Anecdotal experience buying burnt out vehicles at auction, the state trucks with extinguishers are typically only a little burnt.
- mschuster91 2y ago> I guess it’s harder to put out a battery fire than a gas fire? Yep. With a gasoline car, dump water and foam onto the wreck and that's it. If you're really fancy install a sprinkler system in your garage - you can just DIY it if you want, hook up a water pipe to your water mains with a backflow prevention valve to prevent stagnant water from flowing back, add a few heads like [1], and there you go - assuming your water mains has decent pressure, that should be enough to keep a gasoline car fire in check for long enough so that the firefighters can show up and deal with it properly. A battery car fire however? That one is much, much harder to extinguish and it burns way hotter. You need much more volume of water to cool it down enough to approach the vehicle safely, it will cause a lot more damage to surrounding structures, and fire departments haven't gotten nearly as much experience as they have with gasoline car fires. That said, if I needed a car, I'd still go for an electric one, I'd just not park it in a garage directly connected to a home and certainly not in some basement garage. [1] https://koka-shop.de/universal-sprinklerkopf-brandschutz.html https://koka-shop.de/universal-sprinklerkopf-brandschutz.htm...
- KaiserPro 2y ago> With a gasoline car, dump water and foam onto the wreck and that's it Well yes, but you need a lot of water. Fuel fires are not something you can tackle with a domestic hose. However as you point out, normally the reason for a battery fire is because it's shorted, so its not/less oxygen dependent.
- mschuster91 2y ago> Fuel fires are not something you can tackle with a domestic hose. Tackle and extinguish, no. Keep in check long enough to prevent serious damage until the firefighters come in with the big pumps and hoses? Yes.
- khafra 2y agoPeople with ebikes generally charge a .5kwh-1kwh battery indoors every day. Any spare batteries after the initial bike purchase come from Amazon. At that energy density, is there any point to trying to contain a potential fire by, say, setting the battery inside a dutch oven? Or on a stack of sheet rock? Or would it burn well-past hot enough to ignite things outside it? (edit: Dutch Oven has some thermal mass, but too much heat conductivity. Luckily, there is an actual product for this: UL-rated battery storage/charging boxes)
- potato3732842 2y agoThe gas tank doesn't have its own ignition source and oxygen built right into the fuel storage area like a battery does. Leaking gas doesn't all but guarantee a fire the way leaking electrons do. Don't you remember the fire triangle from grade school?
- bluGill 2y agoGasoline in a tank does not burn. Some welders will even weld a tank full of gasoline - it is a safe operation (most welders will refuse to do this, but a few will). The only time a tank of gasoline is a worry is when there are only a few drops in the tank. The above is simple chemistry, the Stoichiometric air fuel ratio for gasoline has a very narrow range where it will burn. A tank of gasoline will be above this and thus not burn.
- s1artibartfast 2y agoCode in what jurisdiction and for what application?
- carimura 2y agoyes exactly we didn't want to firewall the entire garage so I built a structure around the battery.
- numpad0 2y ago5x more usable energy. Energy density of Li-ion cells improve by couple digits or so? if set on fire in expendable mode, if I'm skimming this[1] right. 1: https://www.sciencedirect.com/science/article/pii/S0378775320308892 https://www.sciencedirect.com/science/article/pii/S037877532...