From high output alternator seller QuickStart:
Do I Need a Bigger Battery Wire to the Alternator?
Battery Wire Size and High Output Alternators
When upgrading to a higher output alternator you should always install a larger wire between the alternator and battery. Even with a standard output alternator you will get better performance and life out of your alternator if you upgrade the main battery wiring. The original wire just isn't large enough for proper power transfer. If you are using your alternator to it's maximum output or when you upgrade to a higher output Alternator you must increase the wires size. An alternators ability to send the power it is making to the battery is directly related to the wire size and quality of connection between the alternator and battery. Also, a wire that is to small when used on a high output alternator can cause the power to back up within the alternator making it overheat, burn up and fail.
I guess they also don't understand electricity.
