Battery fuses

[clyst]

I'v just realised that I have about 5ft of unfused cable from each battery to the isolating/changeover switch. To avoid the possibility of an electrical fire(it would be impossible to manually extinguish such a fire due to access)i propose to fit individual fuses to each positive terminal but have no idea which type etc.
Is this the right way to protect against fire or am I missing summin?

 

[Ross D]

Clyst,

I had a similar thought a few months ago and posted the question in the thread below:

http://www.ybw.com/forums/showthread.php?t=248699

The cheapest I found for fuses was:

http://www.furneauxriddall.com/acatalog/Mega_Fuses_Holders.html

However, after much thought I decided the best option was to keep a careful check on the condition of the cable and the connections and not fit a fuse. Splicing a fuse in line where it can get damaged or wet is more likely to cause problems. But I'm still not sure it is the right decision. You need to size the fuse to be less than the current capacity of your cabling.

Ross

 

[alan]

Battery Fuses

You can get fuses which form part of the connector which goes on the battery post; these are fitted as standard by some manufacturers (e.g. Beneteau). I don't remember who makes them but maybe Bluesea (not sure)or next time I'm on the boat I'll have a look for the manufacturer if anyone is interested?

These are the type I was referring to:

http://www.batterytraders.com.au/pd356/terminal-mount-fuse/


Alan.

 

[clyst]

You can get fuses which form part of the connector which goes on the battery post; these are fitted as standard by some manufacturers (e.g. Beneteau). I don't remember who makes them but maybe Bluesea (not sure)or next time I'm on the boat I'll have a look for the manufacturer if anyone is interested?

These are the type I was referring to:

http://www.batterytraders.com.au/pd356/terminal-mount-fuse/


Alan.

I'm interested Alan

Cheers

 

[Ross D]

Alan,

I would be very interested as this seems to be an ideal solution, can you also note the capacity of the fuses.

Many thanks

Ross

 

[RobBrown]

I came across this thread recently in my researches on this issue, which may be of interest:

http://www.sailnet.com/forums/electrical-systems/64546-fusing-your-batteries-another-option.html

 

[sailorman]

Alan,

I would be very interested as this seems to be an ideal solution, can you also note the capacity of the fuses.

Many thanks

Ross

Interrupt Rating satisfies ABYC requirements for DC Main circuit protection on large battery banks
Ignition protected—safe for installation aboard gasoline powered boats
Clear window—visual indication of blown condition
Color coded for each amperage

Available from 30 amp to 300 amp

 

[pvb]

MegaFuses are one preferred solution. Widely available. Well-engineered.

 

[Deleted member 36384]

MegaFuses are one preferred solution. Widely available. Well-engineered.

Absolutely agree. http://www.vte-europe.com/content/electromech/fuse/html/mega/megafuse.php This is what I have fitted. Simple, robust, low cost.

 

[SteveKon]

Fuses

I'm interested Alan

Cheers

I have a power boat with 4 12 volt batterys. You can get a breaker from Kenworth semi truck dealer. They come in 20,30,40,50, up to 100 amps for a cost at about 30.00

 

[clyst]

Right now I know what I need the problem that I now have is what amperage each fuse should be . I have 4 domestic batteries , one start and one bowthruster batteries.

Taking the domestic batteries. Do I add up total equipt amperage and divide by 4 for each battery fuse or does each batterfuse = total usable amperage?? or am I talking complete
b---ox??

 

[VicS]

Right now I know what I need the problem that I now have is what amperage each fuse should be . I have 4 domestic batteries , one start and one bowthruster batteries.

Taking the domestic batteries. Do I add up total equipt amperage and divide by 4 for each battery fuse or does each batterfuse = total usable amperage?? or am I talking complete
b---ox??

It is difficult to answer without wiring diagrams and full specs

The fuse must be rated at slightly more than the maximum current that will be put through it.

I would use:

One fuse for the domestic bank, large enough to carry all the domestic load, or the max charging current, whichever is greatest, if that is not a separate direct fused connection.

One fuse for the bow-thruster bank rated to carry the bow-thruster current.

If you must have a fuse on the starter battery then it must be rated to carry the maximum loaded starter motor current.

In all cases the cables must be rated at least for a current in excess of the fuse ratings. In some cases may be heavier to avoid excessive volts drop.