I'm putting in a 24 volt bow mount. I have the plugs that have four wires going to the back to the plug recepticle. So i will not be jumping the batteries as that happens in the receptacle.

I found some 50 amp auto reset breakers that I am going to use. It says 12 volt on the side.

Can I use this or will I need to find one that says 24 volt?

I'm putting in a 24 volt bow mount. I have the plugs that have four wires going to the back to the plug recepticle. So i will not be jumping the batteries as that happens in the receptacle.

I found some 50 amp auto reset breakers that I am going to use. It says 12 volt on the side.

Can I use this or will I need to find one that says 24 volt?

I recommend a circuit breaker rated for 35 volts or more, since the breaker needs to protect a nominal 24 volt circuit. BassPro has one that should work in your application.
http://www.basspro.com/webapp/wcs/stores/servlet/SceneSevenDisplay?catalogId=10001&storeId=10151&langId=-1&productId=14110&scene7Path=BassPro%2f1422626_i-522694%3flayer%3dcomp%26wid%3d500%26hei%3d500%26fm t%3djpeg%26qlt%3d100%2c0%26op_sharpen%3d0%26resMod e%3dtrilin%26op_usm%3d1.0%2c1.0%2c0.0%2c0%26iccEmb ed%3d0&sourceName=images2%2fLago%2f1422626_i-522694.jpg&type=0&linkEnabled=false

I have one made by Rig Rite Mfg. (part #1050) that mounts right on the battery terminal. Auto reset and rated for 50 amp at 24 volts. Ordered it online but can't recall just where, and around the $10-$15 mark pricewise.

Amps is the amount of electricity, volts is the pressure. So, Volts times Amps gives watts, or the total force a device will have to contend with. In other words, you will get the protection, but the breaker itself will fail permanently because it can't stand up to the additional volts. Hence the other post - get one rated at least for the volts you are going to use, but you can safely go over as you are paying for a more roubust construction. The breaker will still work as intended even with the higher voltage rating. Very bad would be to assume you could go the other way - getting a 100 amp breaker that is only rated for 12 volts. Do that and you will set your boat on fire as you burn out the device!

I would strongly suggest "not" using the 4-wire plug and receptacle for your 24v system, but rather use a jumper at your batteries instead and only use a 2-wire run and receptacle as this will eliminate many future problems for you. If you are using a 12/24v trolling motor, the 4-wire setup is the best option, but if you are using a straight 24v trolling motor, please consider only the 2-wire. In regards to the breaker, purchase the 24v, 50 amp breaker that mounts at the "+" battery post and you will be fine. The breaker is protecting not only the trolling motor, but all of the wiring from the batteries to the front of the boat and back to the batteries. If you use the 4-wire setup, you will need to install two 12v breakers at the batteries (one on each battery) instead.

<<If you use the 4-wire setup, you will need to install two 12v breakers at the batteries (one on each battery) instead.
>>

At first, I thought that would be OK, but if either breaker ever trips, the entire 24 volts will be across that (now overloaded) 12 volt breaker. Draw the circuit diagram and you'll see what I mean.

Respectfully, it makes no appreciable difference as to what voltage is applied thru the breaker whether it be 12v, 24v or 36v, voltage does not and will not overload the breaker and in reality has no bearing, it is the amperage that is applied to the circuit, not the voltage that will cause the breaker to trip (overheat & open). Again, I strongly suggest using a two wire 24v plug and receptacle system making the jumper at the batteries and one breaker, alleviating other potential connection and wiring problems later.

It is correct that excessive voltage will not trip the breaker. If the voltage exceeds the rating for the breaker, the breaker may fail to break the circuit when the current rating is exceeded.

What problems happen when using the 4 wire setup where it gets crossed in the plug?

Motorguide:

I'll try to simplify. The more connections you have in a circuit, the greater potential you have for problems. The existing system in your boat likely came from the manufacture pre-wired for use of a 12/24v trolling motor and that receptacle is required for a 12/24v TM. However, you are converting to a straight 24v trolling motor and will be needing only two of the four wires running from your batteries to your receptacle which reduces a considerable amount of resistance. The way it is now, you have a (-) & (+) from battery #1 and a (-) & (+) from battery #2 going from the back of the boat to the front (receptacle) and the jumper from the (+) of battery #1 to the (-) of battery #2 inside the receptacle. This creates a series connection at your receptacle which is in effect, twice the length of your boat. Bottom line, the more connections in a circuit, the greater the potential for problems. I've seen many receptacles over the years (some my own) that have gone almost to the point of meltdown, mainly due to multiple connection problems. I just completed this same project on a (new to me) used boat I purchased in April and did it this way because of all the past problems I have personally seen (plus I work in the electrical trade).
My suggestion remains as above, jumper at the batteries, replace the existing receptacle with a two terminal receptacle, use the corresponding two terminal plug, install the proper 50 amp breaker at the positive 24v battery terminal, connect your two bank charger back up and you'll be good to go for a long time. On a side note, be sure to use at least a 6 gauge jumper when making your series connection at the batteries.
Good luck with your project no matter which route you go!

Cool. Thanks for the info!

How about a common ground? The owners manual says I should have a common ground.

I'm understanding this to mean that I should connect the negative posts on my trolling motor batteries to the negative post on my cranking battery?

Only the trolling motor is hooked up to the trolling motor batteries. All other electronics etc are run off of my cranking battery.

Thanks!!

Motorguide.
If you are using a 24 volt setup, don't connect both 12 volt batteries to the 12 volt negative starting battery terminal.

However, for convenient jumpering as well as other uses, it is certainly not a bad idea to connect the - terminal of the 24 volt battery.

i.e. look at the 2-12 volt jumpered batteries as a single 24 volt battery.
In this case, sure go ahead and connect the negative of the 24 volt battery to the negative of the 12 volt battery.

Then, if you ever have a need to jumper the starting battery, you only need to have a single jumper connection to the first 12 volt + terminal of the jumpered 24 volt connection. i.e. the jumper to the starting battery will be at the connection spot where the two batteries are jumpered together.

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Hawker is correct in his analysis of the circuit breaker. It is perfectly fine to use the 50 amp 12 volt breaker for your system. The amps flowing through the breaker is what does the circuit breaking.

Hawker is also correct in minimizing his connections in the boat. Fewer
connections mean fewer trouble spots. I have also seen the same thing where connectors and plugs have melted down over use due to poor connections.

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Having said that - if you do use a 4 connector plug - not a bad idea.
Use 2 of the connectors for the + voltage and use 2 of the connectors for the - connection.

i.e. still make the jumper connection at the battery to form a 24 volt battery. Then, run only two wires to the front of the boat.
However, at the front of the boat, connect the + battery voltage to two of the trolling motor socket connections, and connect the - battery voltage to two of the trolling mtoor socket connections.

Obviously, you want to do the same thing for the trolling motor plug, which runs to the trolling motor. i.e. connect the red plus trolling motor wire to the matching two connections of the socket. Also connect the black negative trolling motor wire to the matching two connections in the trolling motor socket.

The reason for doing this is redundancy. i.e. if one of the plug / socket connections get a bit corroded or dirty, the other connection will help to carry the load. Overall, this will reduce the impedance or resistnace of the trolling motor socket plug connection, reduce heating, and deliver more power to your trolling motor.

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As Hawker said, "simplify" and give longer life to your boating experience with fewer problems!!!!!!!!!

Take care
REW


p.s.
Another reason for NOT using the jumpered connection at the trolling motor plug instead of at the battery is the total wire length in the circuit.

Think about this - if you have a 20 foot long boat, you have 20X2 or 40 feet of wire for the plus wire and also 40 feet of wire for the negative wire to the trolling motor.

However, if you make the connection at the battery, you reduce the total circuit length to 1/2. i.e. the plus voltage will flow for only 20 feet. and the - voltage will also only flow for 20 feet. Thus, you have less total resistance in the circuit due to the circuit that is only 1/2 the length.

<<Hawker is correct in his analysis of the circuit breaker. It is perfectly fine to use the 50 amp 12 volt breaker for your system.>>

I must respectfully disagree with this statement. The reason for the voltage rating on the breaker is this: that is the maximum nominal voltage at which the circuit breaker will reliably break the circuit in the event current exceeds the rated amperage. At a voltage above the device's rating, which 24 volts would be in this case, there is too much risk the circuit breaker will fail to break the circuit. This is not a hypothetical situation- I've seen a mechanical circuit breaker with the contacts welded shut due to application above its rated voltage. If the breaker cannot break the circuit, there is danger of electrical fire. It isn't worth the risk to run any electrical component beyond its published rating.

Guys, now I'm confused. I have a 24v set-up with the 2 wires from the plug-in back to the battery. I'm using the jumper wire at the batteries. I currently have a 12v / 50a circuit breaker. Is this okay? Should I use the 24v / 50a one instead? Is there any difference at all?

Smally

Identify the two contact points where you would connect the breaker. Measure the voltage difference between the two two contact points. That is the voltage your circuit breaker must tolerate if it ever trips due to excessive current. You should find about 25 volts in your 24 volt system.

Use the 24 volt breaker.

and here's the Minn-Kota one I used for my 24V TM.
http://www.cabelas.com/cabelas/en/templates/product/standard-item.jsp?id=0031071017271a&navCount=1&podId=0031071&parentId=cat21380&masterpathid=&navAction=jump&cmCat=MainCatcat21276-cat21380_TGP&catalogCode=IJ&rid=&parentType=index&indexId=cat21380&hasJS=true

HRG

Thanks guys. 24v it is.