question about fuses

[Fitz87]

I have 2 identical battereies and a dual output charger. My main question is where I need fuses since the existing wiring has no fuses that I can find. I am also wondering about how to wire the alternator. since the battereis are the same, I could wire to the "all" position on the switch but I know this is frowned upon. Can I just wire directly to both positive battery terminals? I like the idea of wiring to one battery and puting a regulator or something between them because if I decid to add a starting battery then the wiring is already set up for it. If somone can point me to a diagram showing the location of fuses for a "typical" wiring layout I would appreciate it. Also any input on the type to use and how to size them would be great.

Thanks

[mitiempo]

Starting with charging, the best system would be all the charge current to the house bank (one of your 2 batteries at this point) and the other battery (future start battery) taken care of by an Echocharge or ACR. The 1/2/both switch would control use but have nothing to do with charging.

Fuses should be on the positive output of each battery, within 7". The charger output should be fused as well as the alternator output. Fuse sizing is for short circuit protection and not overload protection so the fuse size can be anywhere from the capacity of the wire to 150% of capacity for the main battery fuses. The alternator output should be fused near the battery and the fuse should be above its max output but not over the wire capacity. Same with the charger output.
The easiest way to fuse a battery is with the fuses shown below. They are available with 1 or 2 fused posts and are a neat solution to the problem. They are a Blue Seas product.
Terminal Fuse Block, 1 Terminal Stud - PN 5191 - Blue Sea Systems

[sailingdog]

The only caveat on those fuses is the battery box has to have the height to accommodate them.

[btrayfors]

Originally Posted by sailingdog

The only caveat on those fuses is the battery box has to have the height to accommodate them.

True, but they also work very well on busses, either as a feed to the buss or on any of the connected positive cables. So, a short pigtail from the battery to the fuse/buss would work OK, too.

Bill

[Fitz87]

Thanks,

I think my vertical clearance is tight but I'll check. There is a little space beside the batteries where I could put a bus panel if needed.

Thanks again for the info.

Fitz

[mitiempo]

Buses are a good idea. I try to keep the minimum of wires on a battery post - 1 being ideal. Bill's idea is a good one.

[sailingdog]

Originally Posted by btrayfors

True, but they also work very well on busses, either as a feed to the buss or on any of the connected positive cables. So, a short pigtail from the battery to the fuse/buss would work OK, too.

Bill

And that's an excellent solution for the problem.

[Maine Sail]

Originally Posted by btrayfors

True, but they also work very well on busses, either as a feed to the buss or on any of the connected positive cables. So, a short pigtail from the battery to the fuse/buss would work OK, too.

Bill

Yep, Just be sure to cover the + buss and use terminal caps!!

[Fitz87]

Thanks all, and thanks for the picute Main Sail - I'm going to the boat today and will check the clearance over the batteries and see how much space there is beside them for a bus panel.

Thanks again

Fitz

[fbassi]

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