pnichols wrote:
For years, now, NO ONE has explained the technical reason(s) as to why RV deep cycle dry (AGM) lead acid batteries require voltages greater than 14 volts to charge them fully if one has plenty of time to do less-than-14-volts charging. Is there some electro-chemistry reason - maybe related to activation energies, for instance?
Actually it has been explained many times and it is very simple.
To use a classical reference (Pushing a rock up a hill) for this discussion the "Effective weight" of the rock is what you would see if you put a scale against the rock perpendicular to the hill. IT will of course be a fraction of the actual weight of the rock but this is how hard the rock pushes back against you.
Now if the Effective weight is 13,600 pounds (13.6 thousand pounds) and you push against it with 13.6 Thousand pounds you are going no place fast. the rock will not move.
To move it up the hill you need to PUSH HARDER. perhaps 14,600 pounds will roll it up the grade.
Same with charging a battery. push 13.6 and you go nowhere. that's why it is called FLOAT. .To push amp hours into the battery YOU HAVE TO PUSH HARDER. That's all there is to it.
