You can never have too much amperage when it comes to alternators; therefore, you never have to worry about choosing an alternator with too high of a rated output. Here’s why:Amperage is basically the amount of electrical current your alternator can supply. And it basically operates off of supply and demand. That is, your alternator will only supply the amount of amperage a particular component demands—and no more. So high-output alternators will not harm your components or charging system, no matter how high you go with the amps.