If we were to suppose that a battery were to momentarily slip away from
neutrality, from where might the excess charge come? The only mechanism
which I can imagine is the same as for a capacitor - the addition of
static charge from outside the system. But this we all understand and it
lies outside the problem as asked. The physical entity that we call a
battery is simply a device that allows the dissociation of its electrolite
due to the difference in "electrochemical potentials" developed between
the species in solution and each electrode. Indeed, it is that chemical
potential difference that both sustains the dissociation and causes the
diffusion of charged species towards each electrode. This diffusion may
be thought of as the "current within the battery." This electrochemical
process allows no mechanism for the battery to move away fro charge
neutrality. The "currents within the battery" may also be viewed (at the
microscopic level) as the dissociation of neutral species --- the pulling
apart of that which is neutral into positive and negative pairs. "Battery
neutrality" is therefore a must!
ERTEL SENDS. _____________________
/ Prof. John P. Ertel \
/ jpe@nadn.navy.mil \
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