Electrical panel location

[inprin]

I am building a new electrical panel enclosure at a new location.

New Panel Box

The old one was located in the standard (poor) location at the companionway, above the engine and close to the batteries. I want to move it away from this area to a dry spot as I rewire. I am reusing the old ice box door as a hinged access panel because it will be convenient and the ice box is now gone and just trying to re-purpose as much as possible

Old panel location and Ice Box

. In a perfect world I know you want to keep it close to the batteries and charging sources, etc. so there is not a large voltage drop but which scenario is better: A longer run from the batteries to the panel/switch or a longer run from the alternator to the batteries. And by long run I mean a wire length of about 10-12 feet. I can relocate the batteries close to the panel if need be but would prefer to keep them where they are. Is there a difference either way?

Re-purposed ice box door

[mitiempo]

I agree - wire sized properly will make up for any length issues. Size your wire for both panel feed and alt output for 3% max voltage drop. And don't forget if it is 12' one way you have to allow for the return so it is really 24'. Here's a link to the best wire size calc I have ever used, and I use it very often. Just fill in the blanks.
http://boatstuff.awardspace.com/awgcalc.html

[LazyGuy]

A big factor in the formula is current. Voltage drop is due to current and the resistance of the wire. Bigger wire means less resistance. Voltage drop = Current X (times) Cable Resistance. Once a cable is installed, cable resistance is constant. Therefore as current goes up, voltage drop goes up so what are your big current draws? The Starter is the biggest current draw followed by the Alternator as your biggest current source. Third item, is the charger.

I would do my best to minimize the cable run between the battery and the engine. Everything else on a boat as small as a Triton is small change. That is, assuming you do not have an electric stove, Microwave, A/C, Refrigeration etc....

Just one more humble opinion.

[mitiempo]

True, as current goes up so does voltage drop. Size wires for maximum amperage. Starting and other main battery cables - 2/0. Panel feed - most Blue Seas panels are rated at 100 amps max so size for that based on distance and 3% drop.

The closer the batteries are the better - if only to save the cost of large gauge cables - but if the batteries have to be farther away it can be allowed for.