Not necessarily true you're not starting a motor or running a large electric motor like on a winch you're just charging a battery. So the smaller wire will do the job in fact maybe better then a larger one because it will charge slower instead of a hot charge. I would have to measure it but it a deep charge is considered 2amps or a trickle charge if you will but I'm guessing maybe get more amps out of it then that. Just some food for thought. Oh I can't measure the amps for you guys a blew the amp fuse in my meter and don't have any spares left.