Starter Battery Cable Size

[rapscallion]

I'm having problems getting a clear answer on battery cable size for my Yamaha F150. I am thinking about relocating the batteries to the center console, and can't figure out if I need to increase the cable size or not.

The F150 gives battery requirements in CCA (512A) and MCA (675A), which don't translate directly to wiring charts that calculate voltage drop over distance traveled. If I sized wire based on those figures I'd have a cannon of a wire.

Is this information documented anywhere?

[kingair]

http://www.altronix.com/app_notes/calc.php

http://boatstuff.awardspace.com/awgcalc.html

[rapscallion]

Kingair, that's exactly what I was talking about. You can't enter CCA's or MCA's into that calculator without getting a ridiculous (or unknown) answer. What amperage goes into the calculator?

[kingair]

I would think the amps draw at the engine side, but SIM might be able to answer that question.

[warthog5]

The answer is that you need to know the starter amperage draw.
Then you need to know the cable length + & - added together.

But I can tell you that installing a Dual power post at the transom and attaching the factory cables there and then running 1/0 cable from the power post to the inside of the console will do the trick.

This is based on experience and the fact your talking about a 22ft boat.

That is what is on these 90 Optimax motor;s on this Mako.

[Joe]

Originally Posted by kingair

I would think the amps draw at the engine side, but SIM might be able to answer that question.

^^^What he said^^^

You need total current flow, ie amperage draw during starting and all your other electrical loads.

Figure out your required cable size from that.