You know, anyone could have ended this interminable attempt to get an answer by saying this to begin with:
In general, the micro-behavior of batteries is extremely complex and actually beyond science understanding! It may be shocking but for example, we don't really know or can predict the exact way Lithium batteries charge and discharge.
If you don't know really know that, how can you know that batteries connected as I describe will come to an equilibrium of ZERO volts difference?
Anyway, back to the slog:
On April 8, 2017 at 14:38, amirm said...
I gave that answer :).
No, you didn't. I asked HOW MUCH VOLTAGE. Your response is "more." I agree but it's not the entire answer.
Here is more detail. For current to flow, the voltage as seen by the target battery needs to be higher than its voltage.
HOW MUCH? 1 millivolt? one microvolt? 2.73 microvolts? .04 femtovolts? 42? And... what about the situation causes it to be this value? Avogadro's number is a number that defines something... what's the number that defines the minimum amount that a supply must exceed the battery voltage for current to flow? It can't be zero, so it has to be something. How much is it?
Once that happens, the current will flow. It is as simple as that. It has to be otherwise the most basics rules of electricity flow are violated.
Agreed, except for things at, perhaps, a quantum level (I don't know if that's the right idea to invoke). Perhaps the "voltage" caused by one excess electron is what's required to make that last push to equilibrium. (What if there's an odd number of electrons, so that last electron charge has nothing to push?) Perhaps less than one electron's charge might be present as a voltage, meaning it would be possible to not push any more electrons, yet not be at equilibrium.
That force is simply the voltage differential. Take that away and there is no loop for electricity to complete and flow stops.
Okay, let's try this. Take away half that voltage differential -- there will be flow. Then take away half of that -- there will be flow. Then continue to do this a thousand times. This seems to lead to a condition where a femtoscopic (much smaller than microscopic) voltage differential is present, yet no electrons move.
It simply seems impossible for us to say that a voltage infinitesimally larger than zero will cause current to flow, but no current will flow with zero difference. We seem to be inept at calculations involving infinity or the inverse of infinity.
If you leave them together long enough, they will achieve equilibrium (no electron transfer).
That's a revealing sentence. You're stating that equilibrium is no electron transfer but in the discussions I've had, including this one, people in general have been stating that equilibrium is exactly equal voltages. I'm saying it's possible for the two things to be different and I'm asking by how much might it have to be before current flows.
Note however that the "tail" of this equilibrium may be very, very long. It may take weeks or months to get there. But eventually it will as the two cell voltages equalize.
Time is not an issue in this search.
Upon what do you base your conclusion that there will be zero voltage difference between the two cells? The fact that the question seems not to have been asked, and I've never heard it as a topic, doesn't mean you can ignore it.
At macro level we can simplify things and that works 99% of time. But answering things like dynamic impedance of a battery is amazingly complex chemical process that depends on so many factors from temp to exact condition of material and chemistry. The water analogy by contrast is dead simple.
Yet nobody is willing to say "we don't know."
At macro level, cell to cell equalization happens all the time in battery banks and from personal experience, the cells will equalize over a few weeks.
And you have experience or peer-reviewed reportage that this equilibrium is ZERO volts difference, not femtovolts?
But then as soon as you draw power from them, they lose that and the process repeats again.
That makes sense because this is indeed the macro level compared to what I'm asking about.
