12/24 volt trolling motor hook up- Help

[tkcenterline]

I have a 91 evinrude 57 trust 12/24 trolling motor. When the dealer wired it, he had the two trolling motor batteries and the starter battery in the rear of the boat. It was to much weight. I am moving the trolling motor batteries to the front. The dealer had a 120 volt 20 amp swich at the console up positon was for 24 volt and down was for 12 volt charging. The switch has been to light for the amp. I have to replace it every year because it gets toasted. I was usng two battery chargers to charge both the batteries. I have to put the switch to 12 volt during the charging. Is there a better way to wirer a 12/24 volt system. Maybe use a relay (40-60 amp)in lieu of this 20 amp switch. The trolling motor will work on 12/24. Do I even need a switch/relay. I know enought to get me into trouble. Help I also bought a new 2 bank duel pro battery charger. I want to wire a new system using my trolling motor and new battery charger. Maybe some one could e mail me a diagram?? Thank you

 

[t3699]

Re: 12/24 volt trolling motor hook up- Help

post your email address and i will send you some diagrams

 

[tkcenterline]

Re: 12/24 volt trolling motor hook up- Help

Some of the problems are: when you jump the pos and neg poles (series) to get 24 volts, isn't that a direct short for the battery charger, when they are connected in parallel. Also, I want to connect the starter battery to the trolling motor batteries. Inorder to either charge the trolling motor batteries with the generator or jump the starter battery should it be drained. I was told that you need a isolator? Help!! Can I e mail with a diagram of my boat battery layout.

 

[wilkin250r]

Re: 12/24 volt trolling motor hook up- Help

You cannot connect your starting motor batteries to your trolling motor batteries easily. If you were running 12 volts, it would be easy.<br /><br />The problem is, everything has a common ground. As such, you cannot charge 24 volts with a 12 volt system. In order to charge your trolling batteries with 12 volts, you would have to disconnect them in series and re-connect them in parallel, which could have some complications.<br /><br />Now, if you have a dual-battery charger it MAY be able to charge both batteries while they are still connected in series. It deals with common ground and floating ground, and gets more in depth than you need anyways. Your battery charger literature should tell you if it is possible or not.

 

[tkcenterline]

Re: 12/24 volt trolling motor hook up- Help

I glad to see your reply Witkin. It seems from your other posts, you know your stuff. I am moving my batteries up front and want to wire my own system. In the old system, they ran and made the 24 jump at a 20 amp 3 way toggle switch, which toasted over a long draw from the trolling motor. I know enought to get me into trouble. The things I want to do are: 1. Supply my 12v/24v trolling motor (3 wire). 2. Use my new 2 bank dual charger to charge my trolling motor batteries when pluged into 120v. 3. Jump my 12 v starter battery from one of the trolling motor battery. 4. Charge all three batteries while running the outboard motor. I have a diagram that I drew up for Items I to 3. The diamgram uses 4 buss bars. The diagram is as follows: Batt 1, 12v and Batt 2, 12 v (trolling motor) and batt 3, 12v (starter). Buss 1A pos and buss 1B neg for Batt 1. Buss 2A pos and 2B neg for Batt 2. Buss 1B neg jumps 2A pos for 24 v. Wiring: trolling motor one wire to buss 1A and one wire to buss 1B for 12 v and one wire to buss 2B for 24 v. Wiring: Dual pro 2 bank charger 12/24 volt: 1 bank pos to buss 1A pos and 1 bank neg to buss 1b neg. 2 bank pos to buss 2A pos and 2 bank neg to buss 2B neg. wiring starter batt 3 pos to buss 2A pos and neg to buss 2b neg. The battery charger per the manufacture said that each bank is isolated. This is the system. I just dont know if it will work? Help

 

[wilkin250r]

Re: 12/24 volt trolling motor hook up- Help

It would be much easier to understand with a diagram, but I think I understand what you are saying. Your diagram for your trolling motor batteries is obviously very simple, they are connected in series, and it sounds like your battery charger can handle this without disconnecting them.<br /><br />Now, you also want to be able to jump your starter with one of your trolling motor batteries, which would mean puttin it in parallel across ONE of the batteries (not both). This is also possible, and you don't even need to break the series connection between your trolling batteries. But, you certainly do NOT want it connected in parallel all the time.<br /><br />Now, this is all very simple if you wanted to keep both systems seperate, with the occasional jump start. If you want to charge all three batteries with the outboard, things get infinitely more complex. At that point, you would need to break the series connection between your trolling batteries, and connect them in parallel, and then connect that in parallel with your starting motor. With all these parallel connections, you can develop large loop-currents, which isn't a good idea. I'd then recommend isolators between the batteries to eliminate the loop currents, and with so many connections and dis-connections, it becomes extremely difficult to do with one switch.

 

[tkcenterline]

Re: 12/24 volt trolling motor hook up- Help

Thanks for the reply Wilkin. Let say for the moment, I dont do the charge all three batteries with the motor alternater and just do the jump one trolling motor battery to the starter battery (Batt 3 pos to buss 2A pos and neg to neg buss 2B). What is the best way to wire for this condition? My diagram shows it connected in parallel all the time. Meaning, The starter battery and one of the trolling motor batteries (batt 3) would be under charge all the time from the alternater? Would this circuit have to be broken with a switch. Would one of these 1-2-both battery switches work? If I used a switch to break the circuit and the starter battery was drained, when I flip the switch to jump the dead battery, the dead starter battery would draw all the power from the trolling motor battery. Would this harm my alternater? What is the best way to wire for this jump condition. Would a isolator work here too. Help. I wish I could sent you my diagram. Maybe from the discribtion above you would draw it out. What size isolator and switch would I need to work. I looked up a site called onlinemarine.com. They have many switches and isolators. Cheak them out. Maybe you would advise me on the ones I need, in order the make the system work??

 

[wilkin250r]

Re: 12/24 volt trolling motor hook up- Help

It would be very simple to do with a switch, the only difficult issue would be the size of the switch.<br /><br />What is the most advertised aspect of a starter battery? Cold Cranking amps, or CCA. Forget the cold part, and look at the number. It's usually 750 amps or more. Why do you think that is? Because your motor often requires several hundred amps to start it up. Now, 750 amps is for a big-block 450 cubic-inch V8, so I doubt your outboard requires 750 amps, but it's entirely possible to require 100 amps, maybe more.<br /><br />Does that mean you need a switch rated for 250 amps? Not quite. That rating is based on 100% duty. You're certainly not going to be drawing 100 amps for 8 hours. Hopefully only 10 seconds at most, so you can get away with a much lower rating. I'd recommend a switch with at least a 50 amp rating, and more is safer.<br /><br />So let's say you have your switch, now back to the original wiring diagram. You have your starter battery and one of your trolling motor batteries connected in parallel. Simply put that switch in the line between the positive terminals (the negative terminals can stay connected, it won't hurt anything). When the switch is off, those two batteries are disconnected and your two battery systems are completely seperate. When you want a jumpstart, flip the switch on, start your motor, and then flip it off again.

 

[wilkin250r]

Re: 12/24 volt trolling motor hook up- Help

As I understand it, this is your wiring diagram. I have added the switch for jump starting. Although I imagine your motor actually takes the 12v from trolling battery #2 rather than #1.<br /><br />

<br /><br />The only thing I would say is to make sure of your ground. Your trolling motor has three wires input, correct? What are they labeled? Are they labeled ground, 12V, and 24 volt?

 

[tkcenterline]

Re: 12/24 volt trolling motor hook up- Help

Yes!! This is the diagram I used and I added the On /off switch. It works fine. The only differance is that I added the dual charger and I used a 4 circuit 60 amp terminal bar to make the 24 volt cross over. In this way, all you have to do is hook up the pos and neg leads to the batteries. The charger wiring is simple. The wiring is to connected the pos and neg of the one bank to one battery and the pos and neg of the other bank to the other battery. Some day I would like to have the motor charge all three batteries while I am traveling around in the boat. It would help to top off the batteries as you'r moving to the next fishing spot. Thank you for all of your help wilkin. It was nice of you to reply.