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.

[perchjerker]

Originally Posted by perchjerker

I am not talking about the wire touching the hull

I am talking about the wires touching each other at some point if the insulation get chafed, etc. If that happens before the breaker, the breaker wont do any good on the neg post since the current is not reaching it

sorry I misunderstood

I see what you are saying GBS

[beeman]

The breaker is 50amp with push button. Shutting down is no problem, I added heat shrink tape. Back of breaker I used liquid tape just in case it could arc to metal.

[REW]

Of course the idea of bolting the breaker via jumper bar to the battery is to protect ALL of the battery load wiring.
i.e. if you develop a short any place up stream from the circuit breaker, the breaker will pop without overheating any of the wires insulation.

REW

[REW]

Any kind of grease on the steel bar will keep all of the corrosion away for the life of the boat. You can use common wheel bearing grease if you like with excellent results.
I always smear a good coating of wheel bearing grease on all of my battery terminals before connecting connections. The battery terminal nut will squeeze out all of the grease and insure a gas tight connection. Then, I smear some more grease over the top to keep any moisture off the connections. It is a bit messy, but who is hanging out with their battery terminals. If you do this, you will have 0 corrosion as long as you keep the terminals sealed with grease.

REW

[goldman]

Originally Posted by REW

Any kind of grease on the steel bar will keep all of the corrosion away for the life of the boat. You can use common wheel bearing grease if you like with excellent results.
I always smear a good coating of wheel bearing grease on all of my battery terminals before connecting connections. The battery terminal nut will squeeze out all of the grease and insure a gas tight connection. Then, I smear some more grease over the top to keep any moisture off the connections. It is a bit messy, but who is hanging out with their battery terminals. If you do this, you will have 0 corrosion as long as you keep the terminals sealed with grease.

REW

exactly.

[Schwa713]

Hey guys, the electrons flow toward the postive post.

[WALLEYE651]

i guess the bottom line here is you do it the way you want to and i will do it my way and we are both happy except when something bad happens

[perchjerker]

Originally Posted by Schwa713

Hey guys, the electrons flow toward the postive post.

yes thats technically correct.

was wondering if someone was going to catch that.

As far as greasing a steel bar to prevent corrosion, yes that works but the problem is at the point underneath where the bolt (or nut) contacts the battery. At that point it can still corrode since its not easy to keep grease on that part of the connection while still allowing the current to flow.

Moisture and oxidation can work its way in there. Better to use copper to begin with but nothing is perfect.