full_mosey wrote:
OTOH, how can a charger hold the battery at its charge spec Volts(set-point) unless the charger exceeds those set-point Volts?
Is the definition of transition from Bulk to ABS:
1. when the charger reaches the set-point, or
2. when the battery reaches the set-point?
HTH;
John
It can't hold the battery at a voltage except if the battery is full and floating.
The charger is at its set point from the first and stays at that. The battery reaches that set point when it is full.
The transition to absorption definition "depends". You know it when you see it--amps go from constant amps to tapering amps.
That will occur as soon as the battery acceptance for amps at the then battery voltage becomes less than the charger's constant current limited max amps. However, the charger might have its own program for that "threshold" or it might have a set absorption voltage different (lower) than the high set point.
You can hit the battery with such high amps wrt to battery size in AH it will go immediately into Absorption at the then battery SOC, no Bulk stage at all.
The SOC of the battery at transition depends on the level of the initial charging amps wrt Battery bank size in AH. More charging amps per battery size the lower SOC at transition, and VV. That is shown in my ugly graph I post now and again.
The voltage on the wires between the charger and the battery will be somewhere in the middle. That voltage rises with battery voltage as the middle rises. There is voltage drop along those wires, the amount of drop depending on the amount of current. The voltage on those wires is higher at the charger's end, but it is lower there than the charger's set point until there is no middle when it is squeezed out from the battery voltage reaching the charger's voltage.
