I use lab grade switch mode variable power supplies for all my shop charging duties. This allows me to adjust the voltage to EQ level then adjust the current dial to only what it takes to maintain the desired voltage and no more. I am essentially making it a .5A - 3A max charger vs. a 60A charger for safety reasons. If you've ever had a battery fail/short internally when equalizing with a large charge source such as an inverter / charger then you'd understand why I do this.

Yes the battery is dictating how many amps at XXX SOC and XX.XX volts but if it shorts internally, while equalizing, and you have a 100A charger behind it, well the battery gets really hot in short order.................

The problem that Max may have is that 3A may not get him to 15.5V if the batteries are already sulfated. He may need repeated absorption cycles to get the bank full enough so that 3A can drive an EQ voltage.