[email protected] wrote: > In reply to Harry Veeder's message of Fri, 27 Mar 2009 11:15:39 -0400: > Hi, > [snip] > > The conventional explanation is an internal short, however I wonder about > that. > An internal short can't be any worse than an external short, so has anyone > managed to cause a fully charged battery to explode simply by shorting it > (Vorts > with an experimental bent, and a love of fireworks, this is your chance! :)
Dunno about that -- but the explanation I have run across for the fires in early Mac powerbooks, and maybe some other Li batteries, is that the steel rollers used to flatten the plates which are used in the batteries suffered wear, and tiny steel splinters were -- uh -- "spalted" from the rollers (I think that's the right word). The splinters, which were *really* tiny, went unnoticed and didn't interfere with battery operation ... initially. However, the plates in Li batteries are extremely close together. Under heavy charging current the splinters would "stand up", lining up with the applied E field, and occasionally bridge the gap between plates, shorting them together. We're talking about a situation where the "wire" involved (the splinter) is really thin but also extremely short, and supposedly they'd get hot enough to set fire to or burst the battery. Whatever, take it or leave it, I got this orally from an electric car conversion guy. Don't have a reference to back it up. > > If not, then LENR looks much more likely. > > (BTW, note that in the case below, the batteries were probably not even fully > charged - "I almost reached the third floor".) > >> LENR? >> Harry >> >> Electrolux vacuum explodes, causing third-degree burns >> >> Last Updated: Friday, March 27, 2009 | 10:19 AM ET >> Comments44Recommend29 >> CBC News >> >> A woman is recovering from third-degree burns to her left palm after >> the cordless vacuum she was using to clean the stairs in her Richmond, >> B.C., home exploded in her hands earlier this week... >> >> http://www.cbc.ca/consumer/story/2009/03/26/bc-vacuum-burns- >> electrolux.html > Regards, > > Robin van Spaandonk > > http://rvanspaa.freehostia.com/Project.html > >
