Battery Cables

[Jackman]

What size are you guys using? I have diesel now and want to replace my battery cables...they're large enough but they are shot from years in the bilge. More a of a safety thing for me.

Another thing...I'm thinking I need at least 100A capacity. That would be 2/0, 2 guage or 2AWG? I know one of them is thinner but I get confused about the nomenclature because I'm not an electrician.

Thanks,

Jack

[Pascal]

2 gauge or 2 awg is the same... 2/0 thought is much bigger...

the numbers go down to 0 but then go up with /0

ex 10 8 6 4 2 0 1/0 2/0 4/0

4/0 is as big as it gets, well reasonably, that's what i used for my inverter. on my 53 the main battery starter cables look like 2/0, they dont seem as big as the 4/0

why are you replacing them ? if the insulation is good, they should be fine ? my original cables look good..

[Avenger]

The size of the wire you use on DC circuits depends on the total length of the wire run (both directions) and load. The 100 Amp estimate may be a little low. I would measure the current wire length and verify the amperage with your engine supplier. There are tables to determine required wire sizes. If you can't find one (Worst Marine catalog usually has one) post your info here and we can look it up for you.

[Mike36c]

I ran 2/0 from my 8d's to my 330b's via a switch when I repowered. Remember, starters love heavy wire as voltage drop is minimum.

[the kuz]

Mine are also 2/0 installed durring repower to 330Bs on our 36C.

Regards, Bob K

[Brian Degulis]

You can't get into the ampacity tables here because your starters are a momentary load so they are undersized. In other words a 12v system on an 871 might draw 1000 amps on a cold day if you go to the tables that's going to be a giagantic cable because the size you read off the tables will be continous load. The actual cable used will be much smaller because the starter only runs for brief periods.

You need to tell us the egines you have and the system voltage.

Brian

[Jackman]

330B's 12V system with two *Ds with a 3 battery bank charger. I need to replace them because some of them seem compromised from being in the bilge and occasionally being subject to water over the last 25yrs. They have been in poor shape since I had the boat. I want to improve the system.

[SeaEric]

At the same time that you do this cable job, you may want to consider relocating your battery switches up out of the engine space if they're not already. On my boat the mains are down between the engines and in an emergency it would be nice to have them up and out where they can be easily accessed. This job is on my "to do" list, along with a few hundred other items.

[Brian Degulis]

330B's 12V system with two *Ds with a 3 battery bank charger. I need to replace them because some of them seem compromised from being in the bilge and occasionally being subject to water over the last 25yrs. They have been in poor shape since I had the boat. I want to improve the system.

1/0 will work 2/0 if the runs are long like over 10' Remember the heavier you go the better.

I don't know where your located but if your near the Tampa Fl area PM me We have all the tools to make um up and I can probably save you some money on the cable and ends.

Brian

[Pascal]

good point about the switches... it's on my list too !

I have the older styled blad switches that you pull down, I'm thinking about just adding an emergency pull cable that would let me pull the levers without opening the ER doors.