RV Voltages too high while charging

grizzzman wrote:
IUI Charging

This is a recently developed charging profile used for fast charging standard flooded lead acid batteries from particular manufacturers. It is not suitable for all lead acid batteries. Initially the battery is charged at a constant (I) rate until the cell voltage reaches a preset value - normally a voltage near to that at which gassing occurs. This first part of the charging cycle is known as the bulk charge phase. When the preset voltage has been reached, the charger switches into the constant voltage (U) phase and the current drawn by the battery will gradually drop until it reaches another preset level. This second part of the cycle completes the normal charging of the battery at a slowly diminishing rate. Finally the charger switches again into the constant current mode (I) and the voltage continues to rise up to a new higher preset limit when the charger is switched off. This last phase is used to equalize the charge on the individual cells in the battery to maximize battery life.

AFAIK, The older "single voltage" chargers (not "single stage"... how am I doing BFL :)) did the exact same thing. Current was limited by the chargers current limit, while voltage rose to the voltage set-point, then amps would taper. I don't believe this is a recent development, as you say. So called "smart" chargers simply have an extra stage, called float, or maintenance. The addition of a float stage simply allows one to leave the charger hooked up, indefinitely.

EQ is yet another added stage, but works on the very same principals, namely, if voltage is limited, current will taper, and if current is limited, voltage will rise. But you can't be in both modes at the same time.