what determines the amount of load or amperage a battery can handle, both charge and discarge. is it the capacity or the physical size.
for example could you charge 1500's and 2400's both at 5 or 6 amps safely. or would the 2400's only be smart or should you even stick to 4 amps for the 2400's
i guess its more charge than discharge that i worried about since both batteries i'm sure can handle upwards of 30 amp draw.