A dead LM7812K was the reason I was repairing it...maybe overheat?
Its been a while since I worked on it, but I think that was the measured voltage on the secondary. The initial charging current is determined by the difference between the charger's fast-charge voltage and the battery's terminal voltage, and the inherent over-current limiting of the LM7812K. So, I suppose the maximum would be something above 1A. The settings for the Fast and Float charge pots were what I could pull from battery manufacturing company specs...nothing from Power Sonics. But, these could be anything that works for you.
Ken