Battery terminal fuses

[nctxia]

I am installing MRBF fuse blocks on my battery. Does anyone know what size fuse (they come from 30 to 300 amp) that I should use on a 82 Hunter 25? I also have a starting battery for a 15 hp Mariner, so I need a fuse block on it?

Thanks guys I am trying to learn alot from this group.

 

[woodster]

You can go 150 percent of the battery bank rating if your wire is sized properly. There is a chart on the blue seas site for that information also check the west marine advisory lots of good information there as well

 

[DianaOfBurlington]

Thanks for the info, Woodster; I hadn't known of that rule!

 

[nctxia]

You can go 150 percent of the battery bank rating if your wire is sized properly. There is a chart on the blue seas site for that information also check the west marine advisory lots of good information there as well

Thank you for the info. I plan to go with 100 amp on bank and 150 on starter. Does that seem reasonable?

 

[pvtpotter]

It might be me, but 100 amp strikes me as high. I recall a 40 amp fuse on my dad's boat which had all kinds of electronics, stereo, tv, microwave, etc. We only threw that breaker when water was involved (ingress).
Anyhow, I don't see you pulling more than 40 amps out of the system on a 25' Hunter. With a 100 amp fuse block you are not providing much protection I feel.

Please correct me on this if I'm wrong.
Thanks everyone.

 

[dziedzicmj]

Keep in mind that you are protecting the wire (and not the end equipment or the battery). So your fuse should be sized for the wire and not for what is supplied with that wire.

I think that this link would point you to Main Sail's tutorial on this forum: http://forums.catalina.sailboatowners.com/showthread.php?p=1241401

 

[Ward H]

Keep in mind that you are protecting the wire (and not the end equipment or the battery). So your fuse should be sized for the wire and not for what is supplied with that wire.

I think that this link would point you to Main Sail's tutorial on this forum: http://forums.catalina.sailboatowners.com/showthread.php?p=1241401

And going with a smaller fuse than needed, IE: 40 AMP when wire size would allow for 300 AMP will cause a voltage drop.

As said, read Main Sail's article on fusing battery banks. A lot of good info there.