Alex Holden wrote:

> I do know that the only reason they are not more popular than they
> are is that the electrolyte is extremely nasty stuff (considerably
> more dangerous than sulphuric acid).

  Mmmm, I don«t know about that!  It is certainly quite dangerous to
splash strong alkalis in your eyes, but sulphuric acid is pretty nasty
too.  Both corrode metals, acids usually faster.  Much of a muchness as
to skin damage, you wouldn«t want to drink either...

  I think the main limitation is that they are *wet* - they haven«t a
particularly good gel version.  Nor an overcharge limiting technology,
i.e., you have to top them up with water.

  Cheers,
        Paul B.