Almost everyone can lift that overhead. 90% of men and more than 50% of women can lift a bit more than twice that overhead. It's a common job requirement.
There would have to be something really wrong for an adult to struggle lifting 12kg. That's a large watermelon, and unlike the melon, the fire extinguisher got a handle.
Handheld fire extinguishers top out at that weight - because the vast majority of people will be able to use them and it's better to have two than make them any bigger.
Am from the Southeastern United States.
Before making a guess, try to weight them. I have hard time imagining watermelon (watermelon is the green thing unlike yellow melon) with only 3kg :) Your full water kettle already weights 2+kg.
Regardless, I guess the OP just needs to find a better grocer, local "fruit mongers" up here in frigid Sweden certainly routinely handle watermelons that are way bigger than 3 kg. :)
$ units
You have: 1 watermelon
You want: grapes
* 907.19
/ 0.0011023 $ units
You have: 1 VIM user
You want: Emacs users
St4ck 0verflow...1: https://www.whataboutwatermelon.com/index.php/2018/08/how-he...
Take a look at Bat-Safe LiPo boxes. They are designed to contain the heat and prevent your entire house from going up from a drone battery fire.
https://www.firehouse.com/operations-training/news/21236083/...
Interesting note, the fire was propagating from the back to the floor - where I imagine most of the batteries lies - to the front engine bay but never burned in the cockpit area. I guess those battery equipped cars have some additionnal isolation to protect the passengers.
So spraying water, while it can make it spicier for a bit, allows you to suck away enough heat fast enough that it works okayish. It's the scalable, but not ideal, solution generally.
Current guidance is don't bother with anything else, just spray it until the flames stop.
I've also wondered if maybe EV's should be designed with an easy-to-access coolant loop. For instance, maybe you have a fixture you can connect a garden hose to in order to pump cold water through channels in the battery modules for emergency cooling. (Most EVs have liquid cooling already, so this could be in addition to that, or maybe you hook into the existing system and the already-present coolant gets flushed out.)
just add something gel-forming into the water or some fiber/dust (even just gluten flour) that absorbs a lot of water and turns into kind of watery dough.
The problem it turns out is making large quantities of water based foam (without making it flammable somehow) is easiest when using perflourinated compounds.
Oops.
Let's say you have a battery immersed in a tank of water (aside from the contacts), and you wanted to match the amount of water to the stored energy of the cell, such that, in the event that the stored energy is accidentally released, the last of the water boils away when the battery is empty.
Apparently it takes about 2.37 kwh to boil a gallon of water. That's a lot of energy, but if you have a car with an 80kwh battery pack, you'd need about 33 gallons of water, which is probably too heavy to be a realistic option.
(Granted this is oversimplistic because the energy that comes from a burning battery might be more than the electrical energy you could get out of it just by discharging it the normal way.)
I found a wikipedia article that lists joules per gram required to vaporize various substances:
https://en.wikipedia.org/wiki/Enthalpy_of_vaporization
Water is way up there. Iron and aluminum are even higher, but it's hard to imagine even an EV fire being enough to vaporize large amounts of those. I don't think I'd want to be breathing that either, though given the "battery fire" scenario I guess that's already a given.
That length of time may be zero if the reason it is on fire is due to traumatic damage to the battery pack from a crash or similar.
It’s easier and less error prone to spray it from a distance. If it isn’t on fire yet, maybe it keeps it cool enough it never starts. If it is on fire, just keep spraying until the bad flames stop.
if you don’t have enough water, it will just spread the fire
It’s also relatively simple training and equipment wise (‘spray it with water until the bad flames stop’), and most locations have teams of people on call and ready to do it.
Not perfect, but it’s the best we’ve been able to come up with outside of specialized industrial environments. shrug
So actually a battery can be put out by removing oxygen.
I'm not an expert, so I could be wrong.
A suitable fireproof containment bag + fire-resistant gloves is about $1200 AUD (Brimstone Preventer [1], but I'm sure alternatives are available. This one is small phone/tablet sized and rated for 10k mAh). But most people won't purchase a < $100 fire extinguisher, let alone a battery fire containment device.
>A fire extinguisher large enough for a 500wh battery weighs 12 kilos - most people can barely lift that!
SafeWork Australia (our national OSHA body) recommend loads be kept below about ~16 to 20kg for a single person without mechanical assistance[2] (or up to 55kg with), and most packaging for heavy boxes recommends two person lift starting around 25 to 36kg. 12kg should be trivial for most adults.
[1] https://www.powdersafe.com.au/fire-containment-bag-small-tab...
[2] https://www.safeworkaustralia.gov.au/system/files/documents/...
Is it just me, or is their choice to use mAh—a meaningless unit in this context—a major red flag? Five figures for a bag, and they can’t even get their units right? Is there some “standard voltage” of which I’m not aware?
> Our bags were tested on 4 separate occasions with an overheated laptop, each containing a 3,500mAh - 4500mAh Lithium-Ion battery. The computers melted and burned during these 1 hour tests. The bags showed zero exterior damage. The pull over flaps combined with our carbon liner also absorbed a significant amount of smoke.
That’s meaningless unless we know the voltage. Amp-hours don’t measure energy.
> Tests were conducted with an overheated laptop and cell phone battery (combined capacity of 8,000 mAh- twice as much power as a typical laptop). Our bag passed this test with 100% containment.
Amp-hours don’t measure power—that’d be watts. Neither are measures of energy. This is misleading at best.
Maybe I’m being pedantic, but if I’m paying five figures for a bag and trusting my life with this company, I think it’s fair to expect technical correctness in the product description. This reads like a scam—maybe it isn’t, but the wording is far from reassuring.
Most lithium-based rechargeable cells are nominally between 3.2 and 3.8 volts and are rated in mAh[1]. I would much prefer that they were rated in watt-hours, but they are not.
1: I've seen LMOs with nominal voltages as high as 3.8; LiFePO4 are Nominally 3.2; I think there are some exotic electrode chemistries that are nominally under 3V, but 3.2-3.8 is a fairly solid range for the nominal voltage; voltages at full charge and "empty" will be higher and lower respectively.
$1,100 to contain fire from a phone? No-one is buying it because that's is a terrible deal!
An E-bike battery is like 20x larger, is a containment for e-bike going to cost as much as a car?
But yeah let's blame the consumer, the industry can't be at fault!
Also I had a fire extinguisher, they have an expiration date and now I don't have one.
Not that I'm disagreeing with your overall point, but this I find particularly surprising? My electric scooter weighs 14 kilograms and I carry it everywhere.
That said, adding an extra 12 kilos to my backpack would be annoying, for sure.
However, more and more I am seeing e-bikes ripping around on hiking trails that would get me and my dirt bikes a hefty fine and impound. The risk of fire and contamination is practically the same. And these e-bikes are typically driven by the same people who would call the cops on a gas powered bike on the same trail. The irony is they ride and do peaceful yoga on trails that were made by motor vehicles whose owners were probably gentrified out of their homes. Go figure.
Source? There's very little risk of an e-bike catching fire unless you're charging the battery. Most of the risk will be at home.
Battery fires gets a lot of attention because they're a new thing, but they're far safer than ICE alternatives in almost all circumstances. At least that's what the fire department here in Norway says, and they have pretty good experience with EVs by now.
When you ride trails you sometimes fall down. Sometimes you catch a branch with your bars. Sometimes your bike lands on rocks or logs.
The down tube of an ebike frame is often where the batteries are located. This area takes a lot of abuse from the front wheel and is in perfect position to take damage during frontal impact.
Look up my YT @Platinum_Racing to see an example of terrain that could very easily destroy an ebike or gas bike.
Regarding fire I’d be worried about the hot exhaust on a dry 100+ day.
And I don't think the temperature of the exhaust stream would be enough to light a match 6" away from the tip of the muffler. You'd have to reef on the bike and park it in a pile of dry leaves up to the exhaust header for temperature alone to start a fire.
The problem is when you dump the bike. If you dump it on a tree or a rock you can fracture the gas tank (releasing fuel) or the crankcase (releasing oil). Or if you tip the bike completely over the fuel will eventually be released. Releasing these doesn't imply fire is inevitable. You still need ignition. If a fire starts you can try to smother it.
On an electric bike the same situation applies. If you dump the bike and fracture the battery (that is often attached to the downtube of the frame) then you will have a catastrophic chemical reaction. Thermal runaway is almost guaranteed. You can't even put it out by smothering it.
Furthermore, most lithium battery controllers in consumer devices are proprietary and most consumers have no idea what their true capabilities and thresholds are. Some batteries might be inherently safer than others due to simple firmware that they don't know exists and have no visibility into. There's really no hiding the capabilities of an analog machine.
And most riders immediately remove them because they gunk up with soot and restrict the exhaust.
I had assumed dirt bikes were banned on these trails due to weight and speed, leading to damage to the trail, risks to other trail users and potential structural failure of the often wooden bridges. The risk of fire with a modern gasoline engine is quite small, though air quality effects are significant.
Yes it is illegal but in the same way the 50cc mopeds are supposed to be limited at 45kph (27mph) and all the kids always modified them to go faster. I believe there has always been more unrestricted 50cc mopeds than legal ones in the street. Only some old people kept them restricted.
Most people are willing to take the risk of not getting insurance coverage and a fine once in a while to gain a few minutes per day and be the king of the road. Most only have third party insurance anyway and a bicycle or a moped don't usually create that much physical damage to other vehicules. It only becomes ugly when people hit pedestrians but thankfully and for obvious reasons it is a much rarer event than car drivers doing it.
All gas powered bikes generate heat and pollution. (dry grass + hot pipes for example)
Only defective ebikes will generate heat and pollution
I'd guess that most people can lift 12kg. But lifting and wielding ain't the same.
[1] scroll down to table in https://blog.qrfs.com/66-ultimate-guide-to-fire-extinguisher...
12kg shouldn't be much of a problem for most people, if the weight comes in the shape of a dumbbell and stuff ain't on fire.
But wielding a toddler-sized implement awkwardly in front of a fire while you are a bit panicking yourself, might be a struggle for many people.
Especially since you probably never practiced this, and you might even have to hold the thing one-handed, so you can aim with the other hand
Also you are not benchpressing in optimal position, you need to hold it at an awkward angle.
https://en.m.wikipedia.org/wiki/Unreinforced_masonry_buildin...
https://en.m.wikipedia.org/wiki/Unreinforced_masonry_buildin...
A battery already contains energy, all the chemicals required for the reaction are already present, and once the energy release starts, sealing it from the environment does not stop the process.
Ebike and drone batteries are large enough to be properly dangerous and fire departments make noises about them but offer no solutions. A fire extinguisher large enough for a 500wh battery weighs 12 kilos - most people can barely lift that!
We have no traceability in the battery supply chain and there is no 'battery safety box' that I could readilly buy. It is not clear if an average metal furniture would contain it. And the regulator is sleeping on the job.