Hi Folks
Just a quick question on the charging side regarding suggested battery fuse and cable size.
This is in an in-place inverter upgrade on an RV using a MPII with a maximum charger output of 120A and the suggested cable size seems to be dual 1/0 cables (ie, two positives and two negatives). Along with that, they suggest using a 400A fuse (!!).
I’m using (4) Trojan T-105 batteries in a series/parallel configuration so the end voltage is 12v. According to Trojan, max charging rate should be set to 60A, which I’ve done. The existing fuse is 200A, and I can’t, for the life of me, see that blowing. But it brings to mind why Victron would specify a 400A fuse even when the charger can only put out 120A at the best of times. It seems they want a LOT of over-capacity for that fuse.
Either way, I’m charging 58A max through the existing 200A fuse. Is this OK, in your mind? It seems to be oversized almost by a factor of 4, which seems to be what Victron wants with a 120A charger and a 400A fuse.
On the cabling side, Victron seems to want dual 1/0 cables on each terminal. I have single 2/0 cables, on the order of 2 or 3 feet in length. This is apparently a much larger cable than 1/0 and the length of run is very short. That should be OK too?
I suspect I’m worried about nothing, but just wanted to check in case I’m off base.