I have a 3 bank Xantrex 40 that determines how much each bank needs. I find this problematic in that I only have a total of 40 amps available. I have found the charger will divert about 10 amps as a float charge to each of the 2 banks and then only have 20 amps for the bank that was in need of recharging. I have installed
fuses for each of the three legs. With this I can then pull
fuses from the banks that are not needing to be charged and direct the full output to the bank that needs all it can get. The charger has always worked fine but, it is now hardly ever used due to the
solar system. Still keep it for use with the
generator, which created a new problem due to
generator sizing. I suggest you use an amp meter on each of your banks to see what is really going on.