engine cranking amps and circuit breakers

[allencr]

Odds are, a switch will probably be lot more useful.

Just use a kill switch on the earth side of the battery.

Use seperate fuses for each wire comming off the pos terminal! Work out the correct size fuse for each connection, don't shortcut or guess!!!

I don't know if there is any Fork LIft Earth Mover dump truck race car, factory/OEM/manufactured or kit car that has a fuse/CB, and most if not all don't even have a kill/cut off switch like my early 60's UK POS did,so I doubt that yours is anywhere necessary.
One time that battery disconnect switch may have saved my car from burning up and it is useful for disconnecting when doing wiring work, so I've experienced that it and not a CB would have prevented a fire, and I'd recommend that instead of what looks like bling to me. With 25+ amps before tripping, that CB will really be able to start fires & melt some shit with out even getting a bit warm & thinking about shutting off the current.

[Mos]

Safe Working Limit. Similar concept, just thinking about the headroom needed.

So despite what I wrote you are still wondering about the headroom needed??

25mm^2 does sound like a whole lot, but im not sure how its really measured, since my 120A 4AWG cables are marked 40mm^2

4AWG cable is closer to 20mm^2 so either they have mislabelled it or you're reading the wrong thing

Odds are, a switch will probably be lot more useful.

Problem is that a switch doesn't open by itself (eg when you're unconscious).

I don't know if there is any factory/OEM/manufactured or kit car that has a fuse/CB, and most if not all don't even have a kill/cut off switch like my early 60's UK POS did,so I doubt that yours is anywhere necessary.

On toyotas everything other than the starter cable is fused. I don't know what the deal is on cars with factory batteries in the boot (eg BMWs).

One time that battery disconnect switch may have saved my car from burning up and it is useful for disconnecting when doing wiring work, so I've experienced that it and not a CB would have prevented a fire, and I'd recommend that instead of what looks like bling to me. With 25+ amps before tripping, that CB will really be able to start fires & melt some shit with out even getting a bit warm & thinking about shutting off the current.

You have to calculate if it's likely to cause a fire.... Forklifts use ANL fuses for a reason.... they're not bling. If they didn't protect anything, manufacturers would not use them - it's as simple as that.

Mos.

[Ribfeast]

I used a 150A fuse in mine, got the fuse, fuse holder, and cabling from JB Hifi. Had zero problems.