Where Should I Set My Voltage for Charging

[Knot Tide Down]

I have 4-6volt batteries (U2400) in series/parellal. These are 562 amps x 2 = 1124 amps res capacity. My question is what should I set my alt output too? The manufacture shows the absorption charging at 15.5v (Interstate Batteries FAQ :: How do I charge certain deep cycle 6-volt and 12-volt batteries?). Is 15.5v what I should raise my alt output too?

Thanks

bill

[S/V Illusion]

wet cell, AGM, gels??? it makes a difference

[Knot Tide Down]

Sorry, flooded (u2400 interstate 6 volt).