Sizing a Wire for DC Distribution to a Battery Bank

Question:

I am starting the re wire of my 32 Island Packet. Can you advise the way to choose the proper size wire between the battery and the power terminal strip and battery to the negative terminal strip? Thanks you are a big help in your videos, you make very easy to understand, thanks!  - Jim

Answer:

Hi Jim, the positive and negative distribution of a battery bank, need to be effectively like being at the battery. In other words, you want the wire connecting the battery bank to the distribution to be able to handle all the amperage you expected to run on the batteries and you want to minimize the voltage drop. Consider all the high amperage loads on your boat, for instance windlass, inverter, winches, starter, etc… and make sure the wire can handle those loads. A boat of your size and to be safe, would generally have 2/0 wire interconnecting the battery to the distribution.  - Jeff