RPM drop and electric fans!

20' a 6 ga wire is good for about 30A total:
https://www.qualitypowerauto.com/Wi...ZjHhnEjMd32DJ1YUpnsctiyAoQuD7C6dWCfxEeGUiulrK

Cut that to 6' and it's good for about 120A. This would be especially critical IF the alternator has to push the current to the battery first and then it comes back.

Unless you really need to I'd just put the battery back under the hood.