Most regulators "regulate" by the level of voltage
, not amperage. The amperage regulation is a secondary effect, and is dictated by the battery
bank itself....depending on its type, age/condition, and resultant internal resistance.
Some of the more sophisticated regulators do allow you to control maximum amperage. For example, the Balmar
MC-612 and MC-614 have a "small engine" setting which curtails amperage, and you can also program them to any desired percentage of alternator
output, thereby effectively "derating" the alternator
Be careful with wind
generators and solar panels
. These typically do NOT have effective controllers built in....they need external regulation....and if you fail to do that right they can and will allow voltage to stay high enough long enough to cook your batteries.