Fuse amp for 4/0 wire

[crownvictoria31]

I am running 4/0 gauge excellence welding cable on my set up. From big 3 upgrade to a secoundary battery in trunk. I am currently useing 250 amp fuses from alternator to battery and 250 amp from front battery to rear battery. 

 

Is 250 amp fuse the right size or should i up it to 300amp or more?

[Dafaseles]

Well, 4/0 welding cable is rated for about 400 amps so in theory, you could up the fuse size and still be safe. But I say if you're not blowing fuses, I'd leave it alone

[crownvictoria31]

I am not blowing fuses. I guess im good at 250 then. I thought it would just make a difference in power transfer. 

 

Thanks brother