battery wire

[mariaantoinette]

can any body tell me what amp the wire should be from the battery to fuse box please, and the wire from fuse box to spotlight and horn ect, many thanks

[Chris Pink]

For the domestics and excluding large inverters 25mm² will be good battery to fuse box.

 

For the horn if at the front, depends on the length of your boat but 4 or 6mm² would do. Tunnel light doesn't matter and could be thinner as a bit of voltage drop won't matter.

Edited February 1, 2013 by Chris Pink

[Guest]

For the domestics and excluding large inverters 25mm² will be good battery to fuse box.

 

For the horn if at the front, depends on the length of your boat but 4 or 6mm² would do. Tunnel light doesn't matter and could be thinner as a bit of voltage drop won't matter.

 

Seconded. I have a fuse behind the 25 sq mm cables, and have been told I don't need to do this. Old habits die hard.

 

I made the mistake of thinking 2.5mm sq would be OK for the horn, but it didn't like it. 4.0 sq mm was better.

 

Many tunnel lights I have met would benefit from a little volt drop!

Edited February 1, 2013 by Guest

[mariaantoinette]

Seconded. I have a fuse behind the 25 sq mm cables, and have been told I don't need to do this. Old habits die hard.

 

I made the mistake of thinking 2.5mm sq would be OK for the horn, but it didn't like it. 4.0 sq mm was better.

 

Many tunnel lights I have met would benefit from a little volt drop!

 

thank you both very much for the help

[Tony Brooks]

Seconded. I have a fuse behind the 25 sq mm cables, and have been told I don't need to do this. Old habits die hard.

 

I made the mistake of thinking 2.5mm sq would be OK for the horn, but it didn't like it. 4.0 sq mm was better.

 

Many tunnel lights I have met would benefit from a little volt drop!

 

 

Whoever told you that needs to gen up on codes of practise etc. I bet the ISOs RCD boats are built to demands such a fuse. Just because things are often not done does not make them correct.

 

The horn is a perfect illustration of why voltdrop calculations should be done. Nice one.

[Guest]

Whoever told you that needs to gen up on codes of practise etc. I bet the ISOs RCD boats are built to demands such a fuse. Just because things are often not done does not make them correct.

 

The horn is a perfect illustration of why voltdrop calculations should be done. Nice one.

Yes,I think a fuse is a must, whether they are needed for boat regs or not. I have been surprised to see inverters connected to battery banks without such a fuse, even on professionally built boats.

[Chris Pink]

I think it's ridiculous - you can pay up to £2,000 and they don't have their own fuse. It's cheapskate and stupid - and makes for 2 unnecessary external connections.

[Guest]

I think it's ridiculous - you can pay up to £2,000 and they don't have their own fuse. It's cheapskate and stupid - and makes for 2 unnecessary external connections.

True, that is exactly what I had to do. I put a megalink fuse on the feed to our inverter.