Battery Wiring Sanity Check

[abraxus]

Currently my house battery bank (4 x 125ah) has a battery charger, two bilge pumps and the trim tabs connected to the positive terminal; all are appropriately fused at the battery. Additionally there's a heavier gauge wire going from the positive terminal to the number 2 position on the battery switch, which is not fused.

I was going to just put a big fuse on the cable to the battery switch but thought I'd take the opportunity to remove the clutter from the positive battery terminal, so my plan is to do the following. Please can anyone let me know if this is the correct way to go:

Battery charger with 50 amp fuse remains connected to battery.

I heavy (50mm2) cable from battery to heavy duty (500 amp) bus bar, with a 425 amp fuse at the battery.

Aft bilge pump and trim tabs connected to first post on bus bar, with existing inline fuses.

Fwd bilge pump (with existing inline fuse) to second post on bus bar.

Existing cable from position 2 on battery switch (unfused) to third post on bus bar (do I need a fuse between the switch and bus bar given that there's one bewteen the bus bar and battery?).

Does this sound about right or have I missed anything?

 

[VicS]

I take it that teh battery switch is a 1, 2, both, off switch and that when selected the house battery bank can be used for engine starting.

If so

Fit a fuse either between the battery and bus bar or of the connction is short and direct fit it in the connection between bus bar and switch. Either/or no need for two fuses.

Note any connections to distribution panels or other equipment made to the switch must also be appropriately fused.

 

[abraxus]

Thanks Vic,

Yes it is a 1,2, both, off, switch and the house bank can be used for starting.

As stated above I'll be fitting a 425 amp fuse between battery and bus bar.

The only two load cables off the switch (common post) are an inverter with an appropriate fuse and the single cable for the engine wiring harness which includes engine starting and ultimately feeds all the other house loads. These are all individually fused at the main fuse panel. Are you saying I need to separately fuse this cable at the switch as well?

 

[VicS]

Thanks Vic,

Yes it is a 1,2, both, off, switch and the house bank can be used for starting.

As stated above I'll be fitting a 425 amp fuse between battery and bus bar.

The only two load cables off the switch (common post) are an inverter with an appropriate fuse and the single cable for the engine wiring harness which includes engine starting and ultimately feeds all the other house loads. These are all individually fused at the main fuse panel. Are you saying I need to separately fuse this cable at the switch as well?

I was excluding the feed to the engine itself . This will be protected by the 425 amp fuse ...... but any smaller wires taken from it ought the be fused appropriately at source but it gets a bit silly if you are not careful with fuses of different values all over the place.

 

[abraxus]

Thanks again Vic

There are no smaller wires off the switch, everything is fed via the wiring harness from the engine to the main fuse panel at the helm and so they're all individually fused there, as per original manufacturer installation.

In essence, all I'm changing from original spec is the addition of 425 amp fuse at the battery, but taking the opportunity to tidy up the positive battery terminal with a bus bar.