Connecting Breaker to Trolling motor battery

[tugger]

Originally Posted by GBS

The ONLY way for current to get from or back to the battery should be through the breaker, no matter which post it is on. And that means all wires should attach on the other side of the breaker. The breaker is designed to trip at a given number of amps - lets say 50. If the whole circuit is carrying 45 amps, all is well. If it is carrying 52, the breaker trips - no matter where it is located. If a wire touches the hull, there is no place for the electricity to go. It is not a short, until another path is created from the hull back to the other post on the battery. It makes no difference where what is in the chain - either the chain is complete and conducting electricity, or it is disconnected - either by the breaker, or by whatever melted. In DC circuits, what is before what in the chain does not matter for breaker protection.
What matters is what the weakest link is. An as long as your breaker is the weakest link, you are fine. But, it does take some small amount of time to trip. And during that time, whatever is conducting or getting hot will continue to conduct/get hotter, until the breaker trips. And that happens no matter what post the breaker is on.

A loose wire should never make a spark when touching the hull. If it does, you have a serious issue with something else already "shorting" out. As mentioned, this is different than a car, which uses the whole body as essentially one big uninsulated wire to conduct back to the battery. Everything on a boat should have two wires - one from the battery, one back to the battery.....

That is what I thought. It shouldn't matter, but I am not sure if, even if it doesn't matter, its a "little better" to have it in a certain spot. I have my breaker hooked up between both batteries not on either + or - connection to the plug in for Terrova. Like I said, I don't think it matters. All I was hoping for was a definitive answer on it.