In the phablet, the silent phablet, the LiOn sleeps tonight
AAAEEEEEEE WAAAAAEEAAEEAAEEAEEEEAAAWOOOOOOOO
Now try to get it out of your heads :-)
It has been a bad month for Samsung. Following the release of the dual-curved, 5.7 inch-screen, water-resistant Galaxy Note 7 phablet, the number of fires have increased thanks to its reportedly explosive battery. A number of lawsuits relating to alleged mobile phone combustion have since been filed. The Korean tech giant …
*runs away quickly*
...News at 11.
The more energy you pack in a tighter space, the more likely something will trigger a runaway chain reaction resulting in a fire and/or explosion, and the higher the energy output of the reaction.
Fundamentally batteries rely on a controlled chemical reaction to supply you with energy. if the method of control fails you will have a chain reaction which can get ugly. Lithium is particularly reactive as mentioned in TFA, which is why when these things catch fire it is hard to put them out.
When you reach the kind of density where the energy is locked up in molecular bonds (e.g alcohol) , a spark in the vicinity of the liquid is enough to trigger a chain reaction. LiIon battery tech is not dense enough yet, so unless you physically pierce the battery, or there is a defect/overheating, you are unlikely to suffer these events.
It would be interesting to see if battery technology ever reaches the density of chemical fuels, would it be more or less dangerous than said fuels.
Technically Primary cells are chemically fuelled and unless Zinc Air, the "oxidizer" aspect is built in.
There was experimentation of Butane rather than Hydrogen fuel cell for laptops, but then Lithium replaced NiCd. By volume, the NiMH is now about x5 capacity of NiCd and after 100 cycles, perhaps similar volumetric capacity to LiIon, but much heavier. Interestingly if you "turbo charge" NiMH to get them charged in a hour rather than 10 hours and get it wrong, they go on fire too! I know because I've done it developing a turbo charger (the CPU was 486 SoC, replacing the charge control function with an extra 16 pin PIC solved the reliability issue, the 486 SoC was still used for main GUI and Wireless network monitoring features).
Any fuel cell, in theory, can be higher density than a battery always, because it uses air and could vent the water and CO2 produced. I'm not sure that LiPoly and NiMH are not both higher volumetric capacity than current fuel cells. The cost though of "recharging" a laptop fuel canister from butane, I'd think would be higher than mains electricity and Lithium batteries. Maybe a use case in isolated places with no mains?
> e.g alcohol) , a spark in the vicinity of the liquid is enough to trigger a chain reaction
Contrary to pretty much any action thriller you have ever seen, it is rather difficult to get an explosion from petrol. Hint: firing a few rounds into the fuel tank will make a bit of a mess, but if it catches fire you can probably blame the exhaust
A spark within proximity of a hydrocarbon is not setting the liquid on fire but the evaporated gas (which in turn may produce enough heat to encourage the puddle of fuel to turn into an inferno, but that is secondary to the spark.
In the meantime, forget the spark. Please don't let lithium come into contact with air. Or water. It is really happy to see the back of that electron.
"Shearing advises users to stick to the chargers provided with their mobile phones to avoid generating current or voltage levels that are incompatible with the battery."
In theory most phones have a single cell, 3.7V to 4.2V and a USB charger is 5V -/+ whatever allowed spec. The phone electronics, a little SMPSU controlled by firmware, decides the charge rate. A 5V 200A PSU will STILL only charge at 500mA, 1A, 2A etc, whatever the phone was designed to do.
Only older non-USB connector chargers were other voltages and then you had to use the maker's charger.
> ... your 2 amp charger is delivering 4 times the energy of the 500 milliamp charger ...
Have a downvote for not understanding how these things work.
The 2A supply will only supply more current IF the device demands it. It's a complete and utter myth that swapping out (say) a 1 A supply for a (say) 2A one will somehow "push" more current into the device. The number of times I've had to correct people because they believe that a (say) 85W supply will damage a laptop that originally only came with a (say) 65W supply ... well I;ve lost count.
So if the 2A supply doesn't signal in a way the phone understands* that it can do 2A then the phone will not take 2A - it will limit it's draw to just 0.5A. Now extra current, no extra power, no problem. If the supply correctly signals that it's a higher power device, then the phone may draw more power for fast charging - but it will have been designed to do that and it should be safe.
But if a device isn't designed to use more power, then plugging it into a higher current capable supply will not make it draw any more current.
* There are now standards for signalling, but in the early days, each manufacturer had standards of their own. So (for example) a supply that would fast charge an iPhone wouldn't necessarily fast charge a Samsung, and vice-versa.
Yes, that is generally right, but in the specific case of battery charging there are other factors involved especially in the case of Lithium battery "quick chargers", which play clever behind the scenes to make life a bit less simple.
But the real danger with Lithium batteries is that of undercharge or overcharge conditions, both of which can and will render the battery hideously dangerous. This is why phones and portable computers employ scads of electronics to prevent the conditions occurring in the first place.
This is why, for example, some airsoft guns come with shouty warnings not to leave the charging batteries (which in this case are not protected owing to the cheap and chearful battery packs and chargers supplied) unattended or on charge for more than five hours.
Drone owners employ special "balancing chargers" that ensure a local overcharge of one of the ranked batteries in their drone's battery pack doesn't take place because that would likely cause a fire, and have other devices that warn of an undercharge condition.
I rather liked the datasheet published by one manufacturer of Lion batteries which explained the built-in disc membrane that could rupture if the internal temperature of the battery exceeded 500 degrees fahrenheit, at which point "venting with flame" could occur.
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"Transportation of lithium batteries is also no longer allowed on passenger aircraft," Oliver said."
Except when they are inside a device you are carrying; or when they are part of the plane itself, like the 787 Dreamliner.
IIRC: they never got to the bottom of why the batteries in 787's caught fire in the first place. The "solution" was simply to put them inside a strong metallic box, with a chimney to the outside, to vent off the smoke if and when it does catch fire.
https://en.wikipedia.org/wiki/Boeing_787_Dreamliner_battery_problems#Solution
The solution reminds me of what happened nearly 40 years ago on an airline I will not name when I noticed that one of the panels on the wing seemed to have become loose and told the stewardess; all the blinds on the passenger windows on that side were drawn down by the cabin crew. And it wasn't either Aeroflot or Aeromexico.
One of the problems particular to Li-ion cells is that their internal resistance has a negative temperature coefficient.
With other battery technologies, if you short the cell the power dissipated in the cell causes it to warm up, it's apparent resistance then increases so the max current through it drops and it self limits.
Li-ion batteries do the opposite. In a short circuit the cell warms up, so the internal resistance drops, so the current can increase, so it continues to get hotter... (see icon).
"..except not if it's a Galaxy Note."
A real announcement on a recent flight.
Bit of a kneejerk reaction. Based on reports so far the failure rate has been fraction of a percent.
Still, we're talking about a plane so better to be safe than sorry.
Replacements are have already been shipping (in UK at least) so hardly an issue much longer.
"It's not so much the energy it contains as the method you use to get it out."
Er, no, it's not like that at all.
A Mars bar on its own "contains" no energy. You need an oxidiser, because the energy comes from the redox reaction of carbohydrate/fat with oxygen.
Now, if a Mars Bar consisted of the usual ingredients finely mixed with a suitable quantity of potassium perchlorate, you'd have something they wouldn't let you take on aeroplanes. Before they got hold of Semtex the IRA were rather keen on chlorate/sugar as a method of bringing Marxism to Ulster.
Correct; I should have written "will not engage on its own in an exothermic reaction", though trying to simplify that for the nontechnical in a post of reasonable length could be a little tedious. For real pedantry, though, I should argue that a Mars Bar does not contain energy; it is energy in the form of mass. Something cannot contain itself, as the set theorists got very hot under the collar about in the previous century.
"Edible batteries? Interesting" (allthecoolshortnamesweretaken)
I would not advocate eating batteries containing perchlorate.
OK, so to be more accurate: a 58g Mars bar releases about 1MJ of energy when it reacts with oxygen to form carbon dioxide and water.
A 58g Mars bar when converted entirely into energy would release about 5.2 PJ. (To achieve this you may need to first find an anti-Mars bar)
According to Wikipedia, total UK energy consumption in 2014 was 2249TWh, which I reckon is 8.1 EJ, or about 1,550 Mars Bars.
I've seen other articles claiming that Samsung had nailed it down to the battery itself, and the ones produced by Samsung SDI in particular. The ones they got from a Chinese supplier, used in phones sold in China, have not blown up.
Reportedly they were "squeezing" the batteries to try to fit more capacity in the same volume, and that was done incorrectly in some cases which either put the + and - too close together, or the layer between them was damaged.
As one wag already suggested, perhaps they should have removed the headphone jack to make more room for the battery instead of squeezing it!
"Reportedly they were "squeezing" the batteries to try to fit more capacity in the same volume, and that was done incorrectly in some cases which either put the + and - too close together, or the layer between them was damaged."
Or... They could have made the phones slightly thicker, and enabled them to use a more powerful, unsqueezed battery in the first place.
But that's crazy talk, innit?
Or... They could have made the phones slightly thicker, and enabled them to use a more powerful, unsqueezed battery in the first place.
And for really crazy talk, they could've just had the back cover removable (say, attached with screws and rubber seal to retain the IP rating) rather than glued on and they could have just shipped/replaced batteries instead of whole phones.
"And for really crazy talk, they could've just had the back cover removable (say, attached with screws and rubber seal to retain the IP rating) rather than glued on and they could have just shipped/replaced batteries instead of whole phones."
Kill the heretic! You'll be demanding headphone jacks on iPhones next.