Path: ...!weretis.net!feeder6.news.weretis.net!usenet.blueworldhosting.com!diablo1.usenet.blueworldhosting.com!feeder.usenetexpress.com!tr3.iad1.usenetexpress.com!69.80.99.22.MISMATCH!local-2.nntp.ord.giganews.com!nntp.supernews.com!news.supernews.com.POSTED!not-for-mail NNTP-Posting-Date: Sat, 13 Apr 2024 16:36:49 +0000 From: John Larkin Newsgroups: sci.electronics.design Subject: Re: lithium explosion Date: Sat, 13 Apr 2024 09:35:10 -0700 Organization: Highland Tech Reply-To: xx@yy.com Message-ID: References: <1qrwbfe.1kjz45oeghmx8N%liz@poppyrecords.invalid.invalid> <1qrwznu.1v15g9z1sqvcg0N%liz@poppyrecords.invalid.invalid> <1qrynfd.1tv1btf66ivmeN%liz@poppyrecords.invalid.invalid> X-Newsreader: Forte Agent 3.1/32.783 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Lines: 69 X-Trace: sv3-BMk4RVA7aQ5EDnH/AMVRhP+bWjGN5s0I6qIH9n3GcO/hHvMSNyRlloay/Z+RbKXa8waITrqFFp2ig4V!ZNFyqiDqAKdiEeu3+57fHTJDLR8Q9orOxWo8XI8Q687KdrRZ0yz5dV50uVJf86r6FoGrNjlXOT6H!70IyPw== X-Complaints-To: www.supernews.com/docs/abuse.html X-DMCA-Complaints-To: www.supernews.com/docs/dmca.html X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 Bytes: 4485 On Sat, 13 Apr 2024 16:14:07 +0100, liz@poppyrecords.invalid.invalid (Liz Tuddenham) wrote: >Bill Sloman wrote: > >> On 13/04/2024 3:39 am, Liz Tuddenham wrote: >> > Bill Sloman wrote: >> > >> >> On 12/04/2024 6:55 pm, Liz Tuddenham wrote: >> >>> Bill Sloman wrote: >> >>> >> >>>> ... if >> >>>> it had a safe place to dissipate the stored energy. >> >>> >> >>> What if it didn't? >> >> >> >> Then it probably needs to include a louder hooter and brilliant flashing >> >> lights to serve the same purpose, if more slowly than a purpose designed >> >> dissipator. >> >> >> >>>> ..was being looked >> >>>> after by somebody who ignored the early warnings. >> >>> >> >>> That includes 99% of battery users who wouldn't know what to do it they >> >>> noticed the warnings or wouldn't be able to do it anyway. >> >> >> >> A voice message could be pretty explicit. All the message needs to say >> >> is to move the battery outside to where it can't do much damage if it >> >> bursts into flames. EV car batteries are big enough that that's quite a >> >> way, but cars are designed to move appreciable distances. >> > >> > It's not really a very good selling point. "Oh, by the way, this model >> > has the latest upgrade and tells you when it is going to explode, so you >> > can get out of the way". >> >> You don't seem to have been paying attention. If you deal with the >> warning by discharging the battery, and making it safe, it won't explode. > > >Who it the 'you' in that sentence? Do you mean the average user, in >which case this is a hopeless scenario as most users of batteries >wouldn't have a clue. > >Until recently batteries have been inherently safe: unless you did >something stupid they were unlikely to give any trouble. You are now >supporting a type of battery that is inherently unsafe and will catch >fire or explode unless the user takes some positive action. Even if the >user delegates this action to an automated system there is no guarantee >that the action will be taken every time it is needed. > >'Safety' that depends on taking a positive action to prevent a disaster >is not safe at all. References say that a tiny separator defect spreads radially at centimeters per second. Any somehow-sensed defect will explode in flames in well under a minute, from the bad cell into the whole pack. See Youtube examples... smoke to explosion in seconds. If I heard an alarm from a lithium battery pack, I wouldn't try to fix it, I'd run in the opposite direction. What automated system could discharge an 80 KWH battery pack in a few seconds? Or even 1 KWH? And a defect sensor would have to constantly snoop every cell of a pack. A typical Tesla might have 7000 cells.