Re: (ET) Alum+h2o replacement for acid in lead batteries

["David Roden" <etpost drmm net>]

Though (like many here) I've used batteries for years, I'm no
electrochemist, and in fact even my college chem was a LONG time ago. So 
I'm
far from qualified to evaluate any claims about an "alum" battery.  I 
invite
anyone with a solid electrochemistry background to try to make some sense 
of
what appears to be a rather confused description.

The piece later seems to veer off into discussion of the Chinese silicone
battery. There I'm on slightly firmer ground, having read a little.  Though
it seems that anyone who contacts them gets the marketers rather than the
engineers (if indeed there ARE any engineers involved) and so gets no real
technical information, it appears that the silicone battery is far from
revolutionary.  The silicone compound is a replacement for the silica gel
used in most gelled-electrolyte lead-acid batteries.  It's unclear what
advantages, if any, it really offers.

I was amused by this claim for the silicone batteries: "You can store the
batteries, unused for up to 1½ years with voltage going down less than 1
volt! No memory loss!"  Lead batteries don't suffer from memory effect.  
And
I've stored good quality gel and AGM batteries for that long, and longer,
with much lower self discharge than that.  A decline of 1 volt OC voltage 
in
a 12v battery indicates the battery has lost about 75% of its charge. ;-)


David Roden - Akron, Ohio, USA

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