expected normal voltage drop from load?

BFL13 wrote:
"Now I understand that when a battery is up in absorption voltage range, the amps required to hold Absv keep tapering. If the amps do not taper then voltage will just keep rising"

This concept still bothers me. I don't believe the amps keep the voltage up.

The charger voltage is kept up by itself. The battery voltage is based on the SG of the electrolyte. The difference between the two voltages makes for amps across the R.

If the charger voltage is maintained amps will taper as battery voltage rises.

I don't think that if you somehow dropped the amps (by having a lower amp current-limit charger?) but kept charger voltage steady, that battery voltage would suddenly drop too. I think it would just rise more slowly from then on.

I think LY has the tail wagging the dog, but I could be missing something in all this.

The charger just plain can't "drop the amperage" without simultaneously lowering the output voltage at a given state of charge, etc; that's physically not possible. A given applied voltage implies a certain specific current flow, and vice-versa.

If the charger is operating in a current limited mode (or is a constant-current supply, which is more or less the same thing), then the voltage is being regulated to produce that current. If it's operating in a constant voltage mode, then the current is basically being regulated to meet that voltage. (Technically, in either case, it may be slightly more correct to say that the charger regulates its power output to achieve the desired current or voltage setpoint, but that's splitting hairs.)