The risk seems vastly overblown to me. Unfortunately, lithium batteries catch fire sometimes. One can do a google search for iphone fire and find examples there too. The problem is that we all want as much battery life as possible. This leads to using battery chemistries that are more energy dense. Those also tend to be the more volatile. Compounding this problem, I would imagine they're also probably trying to get close to the upper and lower limits of the battery voltage too. Adding those things together, it's no mystery why phones are getting more and more likely to burn up. It should have worried everyone that Note7 phones were supposed to have vastly better battery life than anything else on the market. That would seem to be a sign that maybe they're trying really hard to push the outer limits of battery technology. But, there are millions of Note7 phones and only a handful have burned up. I haven't got all of the numbers right at hand but I'd bet if you crunched the numbers a similar percentage of Tesla Model S cars have burst into flames compared to Note7 or iPhone 6/7. Then, shall we mention the number of gasoline powered devices that have burned themselves up?
Allow me to offer that I'll take any Note7's that people don't want off of their hands. I'm not worried about it. Bottom line, news agencies like controversy and they found it. On Mon, Oct 10, 2016 at 7:28 AM, brucedp5 via EV <[email protected]> wrote: > > > % I marked this as OT as it is not directly EV related. During both > departing and when returning my recent flight, the attendants in the > waiting area annouced over the PA that anyone with the above phones were to > see them (meaning those batteries were a serious problem). While this news > item is mainly focused on phone batteries, they just had to throw in that > batteries are used in EVs. > > ? 'as EVs struggle to go 350mi' ? > ? 'Batteries should never be left constantly plugged in' ? > % > > https://www.theguardian.com/technology/2016/oct/10/samsung-how-batteries-work-smartphones-explode > Charged issue: how batteries work – and why some of them explode > 10 October 2016 Samuel Gibbs > > [images > https://i.guim.co.uk/img/media/cc0aecbf7f8524f97c6485b3a129fd6b565ec567/0_127_3888_2334/master/3888.jpg?w=620&q=55&auto=format&usm=12&fit=max&s=5a1f37b2d94e19b5ffe562165c462484 > Battery exploding out of a 17in MacBook Pro battery casing due to swelling. > Photograph: J Aaron Farr/Flickr > > https://i.guim.co.uk/img/media/f64c085123e3898e4353e975df17be0a2ac3374c/0_0_3500_785/master/3500.jpg?w=620&q=55&auto=format&usm=12&fit=max&s=11dd5e15333bef31ef0bb0213c3c8ac7 > A combination photo shows a Samsung Note 7 exploding as pressure is applied > to its fully charged battery during a test at the Applied Energy Hub battery > laboratory in Singapore, 6 October. Photograph: Edgar Su/Reuters > ] > > [image] enloop rechargeable batteries We rely on batteries to keep our > modern lives powered up. How can we make them safer and longer lasting? > Photograph: Pete Slater/Flickr > > Batteries fuel modern life, from smartphones to electric cars. But how do > they store electricity and why don’t they last long enough? And, as Samsung > might be asking itself, why do they blow up? > > Battery life is an explosive issue. Literally, as Samsung is discovering to > its dismay. The company’s Galaxy Note 7 smartphone was praised upon release > for best-in-class battery life, far outpacing its key competitor, the > iPhones 6S and 7 Plus. Then it started blowing up. Samsung issued a recall > and replace programme, and the replacements also started blowing up, forcing > the company to suspend production entirely. > > The affair marks the latest road block on the long fight to improve the > batteries that power our electronics. While processing speed doubles around > every 18 months, battery capacity takes almost a decade to improve to the > same degree. That gap is starting to cause problems, but as Samsung has > found to its cost, it’s not easy to fix. > > A smartphone often lasts less than a day, a laptop sometimes only a few > hours and an electric car struggles to go 350 miles. So why is it that > battery life is still such a problem – and when are we going to fix it? > > What is a battery? > [image] Inside that plastic and metal casing is a little box of chemicals > ready to react and create electricity. Photograph: BitchBuzz/Flickr > > Batteries are small containers of chemical energy. When a smartphone is > plugged into the mains, electricity is used to reset a chemical reaction > within the battery, transferring electrons from the negative anode to the > cathode – the positive end of the battery. > > Once charged, the battery can then create electricity by driving electrons > through a circuit, in this case a smartphone, to the anode and will continue > to do so until all of the electrons contained within the battery have > transferred to the anode or a built-in switch disconnects the battery. > > What is a battery made of? > Inside a typical battery you have an anode, a cathode and electrolyte – > something for the positive ions to travel through. > > Lithium-ion batteries found in most smartphones and electronics have a metal > oxide cathode made of a cobalt, nickel, manganese or iron mix, a porous > graphite anode that holds lithium ions within it and a lithium salt > electrolyte. > > Positively charged lithium ions travel through the electrolyte from the > anode to the cathode driving electrons through the smartphone as required > and back to the anode. > > Why doesn’t it last long enough? > [image] Low battery symbol on the Nokia Lumia 800 in a jeans pocket. > Photograph: Martin Abegglen/Flickr > > The principle of the battery may be simple, but the chemistry and technology > to make it work is not. The major limiting factor for batteries is their > energy density. > > A battery can only generate as much electricity as its chemical components > can store energy. Everything that is not the active material within the > battery is effectively dead weight, including the casing, the controller > chips, the wires to carry the current out – they all add weight but not > power. > > A typical lithium ion battery within a smartphone has an energy density > around 150 Watt-hours per kilogram (Wh/kg). While Lithium ion battery energy > density has improved since its introduction in the early 1990s, it is held > back by its construction and chemistry. > > The only way to immediately increase a smartphone’s battery life with > current technology is to increase the power efficiency of the smartphone’s > electronics and increase the size of the battery – but thinner and thinner > smartphones demand thinner and thinner batteries. > > Why does battery life diminish? > [image] macbook pro battery meter Fully charged, or is it? Over time the > battery can’t store as much energy as when new. Photograph: Bastian > Greshake/Flickr > > Battery life doesn’t stay constant for the entire life of a smartphone – it > diminishes slowly over time, as the battery is discharged and recharged. > > This is because the chemical reaction that produces the electricity causes > thin layers of lithium to be laid down on the electrodes, which reduces the > amount available to generate electricity and increases the internal > resistance of the battery. > > The higher the resistance the harder the battery has to work to maintain a > usable voltage and so the amount of power it can produce per charge > decreases. You might remember this bit from school: > > Voltage = Current x Resistance (V=IR) > > Why do some batteries explode? > [image] swelled macbook pro battery Battery exploding out of a 17in > MacBook Pro battery casing due to swelling. Photograph: J Aaron Farr/Flickr > > Batteries with much higher energy density than lithium-based cells are > already available, but they aren’t safe enough for use in portable > electronics. > > “The more energy you put into a box, the more dangerous it’s going to be,” > says Dr Billy Wu, lecturer at Imperial College London’s Dyson School of > Design Engineering. “Safety is absolutely key and thermal management is > crucial. If a battery heats up beyond 80C you hit what is called thermal > runaway, where the components start to decompose, and that’s when it can > explode.” > > The specific cause of Samsung’s issues with exploding batteries is unknown, > the company just cites “a battery cell issue”. > > What happens next? > [image] A rechargeable lithium-ion battery We’re stuck with the > rechargeable lithium-ion battery for the time being. Photograph: > Razor512/Flickr > > In the immediate term, battery advances will come by bringing existing > lithium-ion technologies closer to their theoretical limits, which will > increase the power density of batteries. > > A typical lithium-ion battery using lithium manganese oxide has a > theoretical power density of 280 Wh/kg, but the final product only has > 150Wh/kg so there is certainly room for improvement. > > “It’s about optimising the structure within the battery,” says Wu. “If you > imagine inside your battery you have this porous structure full of the > active material.” > > “For higher power output, you need a more porous structure to increase the > surface area and allow more lithium ions through at any one time, but > because it’s got more holes it holds less active material, which in turn > gives you lower capacity.” > > New, advanced battery chemistries such as lithium-sulphur and > lithium-silicon are also being worked on, with companies around the UK > currently developing the technology. > > What is the future of battery technology? > Solid state batteries are one possible future, where the liquid electrolyte > in the battery is replaced by a solid substance, which will provide > significant safety improvements. > > “The main advantage of solid state batteries is that you can go back to > using lithium as the anode material, which has really good power and energy > density, but wasn’t safe with liquid electrolytes,” explains Wu. > > Solid-state batteries will remove the need for the porous carbon anode and > therefore removes more of the weight from the battery that doesn’t > contribute to generating power. > > Metal air batteries, using zinc, lithium or aluminium are also on the > horizon, but are 20 years away from being available in a commercial > application according to Wu. > > What can I do to help my battery last longer? > [image] low power warning on a samsung tabpro s A familiar sight for > anyone with a smartphone, tablet or computer. Photograph: Samuel Gibbs for > the Guardian > > There are a few things you can do to help prolong the life of your battery. > The nature of the chemical reaction inside the battery means that it has to > work harder in the last 20% of discharge and above 80% of charging. > > Keeping a lithium ion battery roughly between 80% and 20% of charge will > help it keep a greater amount of its capacity for longer. Smart power > management systems are currently being developed that do just that when > plugged into a wall overnight. > > Batteries should never be left constantly plugged in, which is particularly > applicable to laptops. They are kept in better working order if they are > discharged and recharged every so often. Once a month should do it. > [© 2016 Guardian News and Media] > > > > > For EVLN EV-newswire posts use: > http://evdl.org/evln/ > > > {brucedp.0catch.com} > > -- > View this message in context: > http://electric-vehicle-discussion-list.413529.n4.nabble.com/OT-Samsung-Galaxy-Note-7-li-ion-batteries-blowing-up-fiction-facts-opinions-tp4684045.html > Sent from the Electric Vehicle Discussion List mailing list archive at > Nabble.com. > _______________________________________________ > UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub > http://lists.evdl.org/listinfo.cgi/ev-evdl.org > Read EVAngel's EV News at http://evdl.org/evln/ > Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA) > _______________________________________________ UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub http://lists.evdl.org/listinfo.cgi/ev-evdl.org Read EVAngel's EV News at http://evdl.org/evln/ Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)
