Yeah its crazy enough, the idea is to keep the voltage perfectly stable when coding, There are ones like this:

https://www.amazon.com/Schumacher-IN.../dp/B002Z2Z7ZY

Its 1360W at 13.6v so a 13a fuse should handle it, but the more I look into most people just use a 25A supply without issue.

Thanks for the offer I have a CTEK battery tender that has a supply mode at 13.6v but its only at 10a, I might look at making a supply to do this.