Lee, Thank you for your extensive reply.
As I said in my message, while doing an equalizing charge, with the cells bubbling merrily away, I have to believe that the space above the electrolyte in the cell case is completely hydro/oxy, all the air is long gone. This would completely fill the space with 66% hydro and 33% oxy as in H2O. If not that exact ratio then something approaching it. Whatever it really is, the space is filled with pure oxygen and pure hydrogen in exactly the ratio to produce pure water when burned. Yet batteries do not routinely blow up when being charged, even with an equalizing charge. What is it that causes the rare but spectacular charging explosions? I have certainly heard of oxygen itself causing lube oil to combust. It is part of the first safety lesson in every welding class. Keep pure oxygen away from anything with oil on it, as in rags and clothing. Even the pressure gauges state right on the face "Use No Oil". While oily rags exposed to pure oxygen can combust, we are not dealing with pure oxygen here and there were no smoking rags nearby after the two explosions I know of (thus the phrase "no apparent cause". I find it difficult to believe that editor of Home Power would have such a faulty terminal so as to make it get up to the combustion temperature of oxy/hyd. Neither does the "molecules rubbing together" or luck seem a likely answer. Personally, I suspect arcing inside the cell. Since both batteries were being heavily charged at the time, perhaps there was enough plate distortion to cause the edges of two plates to touch. That certainly would do it. Since you found little about the subject on line, and it apparently doesn't happen often, perhaps (hopefully) it is a such a rare occurrence that we really don't have to worry about it. Norm S/V Bandersnatch Lying Julington Creek FL 30 07.72N 081 38.4W > [Original Message] > From: LA Licata <[EMAIL PROTECTED]> > To: <[EMAIL PROTECTED]> > Date: 12/31/2007 7:20:44 PM > Subject: Re: [Liveaboard] Battery Explosions > > Norm, > > a quick google search did not turn up the numbers that I wanted, but > from my Oxygen saturation dive days, oxygen concentrations between > 30-80% (I think!) are in the spontaneous combustion region, while > hydrogen has a wider band. > > Aging, a quick google search did not turn up the numbers I was > looking for, but I think that something as low as 3% hydrogen > concentration to as much as 90% is the region that supports > spontaneous combustion. > > To set this all off one needs "friction." The source can be the > rubbing of the gas molecules together, or a hot terminal, or some > oil / gas/ diesel soaked rags, or ... luck. > > Now, in most cases, the hydrogen and oxygen generated during charging > are swept away because, let's face it, our engine compartments are > not too well sealed. > > But, if water level is low, and the cell's cap is tight, and is the > cell gets warm enough during the charge, the H2 build up about the > plate region has enough space to collect the required amount of gas > to explode. > > That is why I in my original post I said I watered the batteries > before equalization and took the tops off. > > Again, mostly from memory, and, this is after my New Years' Eve > party.... > > Lee > > On Dec 31, 2007, at 19:26 , Norm of Bandersnatch wrote: > > You statement about the spontaneous combustion of concentrations of > oxy/hyd > is of great interest. > > What more can you tell us about that. During heavy charging I > imagine the > entire "air" space above the plates must consist only of oxy/hyd in the > perfect proportions to explode nicely. Since that is not a regular > occurrence I wonder what conditions are required to set it off. > > > > Norm > S/V Bandersnatch > Lying Julington Creek FL > 30 07.72N 081 38.4W > > > > > > As for a potential source inside the battery to cause a spark, there > > probably is one in theory, but not probably. Surrette's battery > > maintenance course never mentioned an inside the battery source as a > > possible cause for a battery explosion. > > > > As for unexplained sources, there are concentrations of O2 and H2 > > that can spontaneously combust so that could be one explanation... > > > > > _______________________________________________ Liveaboard mailing list [email protected] To adjust your membership settings over the web http://www.liveaboardnow.org/mailman/listinfo/liveaboard To subscribe send an email to [EMAIL PROTECTED] To unsubscribe send an email to [EMAIL PROTECTED] The archives are at http://www.liveaboardnow.org/pipermail/liveaboard/ To search the archives http://www.mail-archive.com/[email protected] The Mailman Users Guide can be found here http://www.gnu.org/software/mailman/mailman-member/index.html
