Peri, Watch the video, You Tube title is: " eSamba EP 29 TESLA style fuses " The many parallel packs in series depend upon each pack not having multiple failures, one or two in each pack are no problem there are about 50 cells in each parallel group. If a catastrophic failure should happen and a cascade of the cell fuses blow, the car just stops and you get the battery pack replaced under warranty the first 8 years or 100,000 miles. (in a TESLA)
Dennis Lee Miles (*evprofes...@evprofessor.com <evprofes...@evprofessor.com>)* * Founder: **EV Tech. Institute Inc.* *Phone #* *(863) 944-9913 (12 noon to 12 midnight Eastern US Time)* *Educating yourself, does not mean you were **stupid; it means, you are intelligent enough, **to know, that there is plenty left to learn!* * You Tube Video link: http://youtu.be/T-FVjMRVLss <http://youtu.be/T-FVjMRVLss> * * NEW You Tube Video link: *http://youtu. be/Pz9-TZtySh8 <http://youtu.%20be/Pz9-TZtySh8> On Tue, Aug 19, 2014 at 9:12 PM, Peri Hartman via EV <ev@lists.evdl.org> wrote: > So, if you want individual fusible cells, then a bus bar on both terminals > won't work. One side can be spot welded but the other side needs the fuse > wire - or something. Not sure how that could be done in this model. Does > Tesla really have each cell fused? > > Part of my idea is to make each module easy to connect and swap out, if > needed. Also easy to pack into a tray. > > > Peri > > ------ Original Message ------ > From: "Dennis Miles via EV" <ev@lists.evdl.org> > To: "Lee Hart" <leeah...@earthlink.net>; "Electric Vehicle Discussion > List" <ev@lists.evdl.org> > Sent: 19-Aug-14 5:29:00 PM > Subject: Re: [EVDL] CALB bolt terminals getting hot - > > The cells in the TESLA pack are a group in parallel then the parallel >> groups are wired in series for the desired voltage, The key to pack >> survival when a cell fails is a fusible link (Correctly sized short length >> of wire) in series with each and every cell then any malfunctioning cell >> is >> isolated when the link opens. (Reducing pack capacity about 2%.) >> >> Dennis Lee Miles >> >> (*evprofes...@evprofessor.com <evprofes...@evprofessor.com>)* >> >> * Founder: **EV Tech. Institute Inc.* >> >> *Phone #* *(863) 944-9913 (12 noon to 12 midnight Eastern US Time)* >> >> *Educating yourself, does not mean you were **stupid; it means, you are >> intelligent enough, **to know, that there is plenty left to learn!* >> >> * You Tube Video link: http://youtu.be/T-FVjMRVLss >> <http://youtu.be/T-FVjMRVLss> * >> >> * NEW You Tube Video link: *http://youtu. be/Pz9-TZtySh8 >> <http://youtu.%20be/Pz9-TZtySh8> >> >> >> On Tue, Aug 19, 2014 at 7:32 PM, Lee Hart via EV <ev@lists.evdl.org> >> wrote: >> >> Peri Hartman via EV wrote: >>> >>> To take this to a traction pack, I would want to try a similar design >>>> where strings of cells are spot welded in parallel for the desired >>>> current load. As I understand it, you can put as many in parallel as >>>> you >>>> want and control them with a single BMS unit. >>>> >>>> >>> Well... There are those that believe this, and it is certainly done. >>> >>> However, think about failure modes: Sooner or later, a cell will fail. >>> What happens if one of the cells in parallel shorts? All the rest will >>> dump >>> all their stored energy into that one shorted cell. That is very likely >>> to >>> result in a burst cell or even a fire. And packed like this, once one >>> cell >>> starts burning, it can set the rest on fire. >>> >>> When laptop manufacturers connected their cells directly in parallel, >>> there were some dramatic failures and fires. Since then, reputable >>> manufacturers are using cells with *internal* fuses and safety devices. >>> Hobbyists and el-cheapo manufacturers aren't likely to use such cells. >>> >>> -- >>> The principal defect in a storage battery is its modesty. It does not >>> spark, creak, groan, nor slow down under overload. It does not rotate. >>> It works where it is, and will silently work up to the point of >>> destruction without making any audible or visible signs of distress. >>> -- Electrical Review, 1902 >>> -- >>> Lee Hart's EV projects are at http://www.sunrise-ev.com/LeesEVs.htm >>> >>> _______________________________________________ >>> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub >>> http://lists.evdl.org/listinfo.cgi/ev-evdl.org >>> For EV drag racing discussion, please use NEDRA ( >>> http://groups.yahoo.com/ >>> group/NEDRA) >>> >>> >>> -------------- next part -------------- >> An HTML attachment was scrubbed... >> URL: <http://lists.evdl.org/private.cgi/ev-evdl.org/ >> attachments/20140819/de521326/attachment.htm> >> >> _______________________________________________ >> UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub >> http://lists.evdl.org/listinfo.cgi/ev-evdl.org >> For EV drag racing discussion, please use 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 > For EV drag racing discussion, please use NEDRA (http://groups.yahoo.com/ > group/NEDRA) > > -------------- next part -------------- An HTML attachment was scrubbed... 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