I have installed a couple of consumer units to provide switching and protection for individual circuits but there are still two 'master' fuses between the batteries (separate leisure and starter batteries) and the consumer units feeding all the circuits.
The existing fuses are 'bottle' fuses and I'm wondering whether to retain them or to replace them. I certainly want easy to replace fuses (i.e. not needing a screwdriver or spanner) as one doesn't want to have to find tools in an emergency. I need something in the region of 60 to 100 amps though. Currently one fuse is 63 amps and the other is 35 amps. If I stay with the bottle fuses I want to make both 63 amps which means I need to change one of the fuse holders and getting a replacement fuseholder may be a problem although it looks as if Farnell have a possible DIN rail mounting holder, I'm not sure how easy this will be to fit.
So, are there any reasonably economical alternatives with 'replace by hand' fuses with ratings in the 60 to 100 amps region? They want to be reliable as well though don't need to be capable of use at high voltages, this is a 12 volt system.
Then, in addition, I want to protect the 'heavy' stuff. The starter battery also feeds the starter motor (surprise!) and the bow propellor. Currently (no pun intended) these are wired direct to the battery and I'm thinking some sort of protection for this wiring would be a good thing too. The connection to the bow propellor in particular is long and circuitous and a fault could easily start a nasty fire in an inaccessible place. The wires from the batteries to the existing bottle fuses are also unprotected (only a couple of feet or so, but still a fault is possible).
I'm thinking that the easiest approach for this is a fuse in the ground wire to the batteries, it's where the battery isolation switches are already wired so adding a fuse here would be reasonably accessible. It looks to me as if a couple of Littelfuse 'mega fuse' links would do here, they have screw connections but at around 500 amps I guess that's inevitable. Are there any practical alternatives to the 'mega fuse'?