24v Wiring Set-up

[Mid-Lake Rock]

I have a newer used boat with a 24v trolling motor setup. There are two positive and two negative connections for each battery. These come from trolling receptacle and the on board charger. I get how this works. However, there is also a red wire that is not grounded to anything. I asked the previous owner and he said this is used to link the positive terminals on each battery for the charger. Is this correct? Do I need this? Do I link it between the two positive terminals? Thanks.

[rmrakt]

With a 24V system you need to put the 2 batteries in series. 12V + 12V = 24V

You will have a red wire and a black wire coming from your 24V trolling motor.

Put black wire from motor on negative terminal on 1 battery.

Put red wire from motor on positive terminal of other battery.

Place jumper wire between the 2 open battery terminals ( -to +).

If you have a 2 or 3 bank charger the leads from the charger go directly to the positive and negative of each battery.

I have a jpeg diagram of this set up and could mail to you if you need....I'm not set up to post pics here yet...

[Ralph Wiggum]

Not true in all cases. Some boats have leads from each battery and the jump to 24v is made at the plug.

[Mid-Lake Rock]

Rmrakt,

Thanks for the response. I think my set-up is a little different than you describe. Sorry if this is confusing. The boat is an 04 Crestliner Fish Hawk. I have two batteries mounted bellow the front casting deck. The receptacle to plug the trolling motor is on the bow of the boat.

Under the casting deck there are two black tubes running from the bow. Each tube has one red and one black wire. One set of red and black per battery. Lets label them tube one and two. I take the red and black from tube one and put them on battery one. I do the same with tube two to battery two.

There are then two large cables that run from the charger. Each large cable has one red and one black. I attach one set to battery one and the other set to battery two. The motor works.

However, that then leaves the jumper wire. Is the jumper wire needed? The guy I purchased the boat from said it was needed to link the batteries for the charger to work properly?

[Satchmo]

If you have a four wire system coming from your front trolling motor receptacle as you describe do not use the jumper wire for ANYTHING. Wire it just as you described in your last post. Tube 1 red & black to battery one, tube 2 red & black to battery two, and one set of charging wires gets wired to each battery. The plug on the trolling motor must be wired for 24 volt for your motor to work properly.

[rmrakt]

yup.....your set up is different than what I pictured!

If you have a voltmeter make sure you have 24V at your plug to be sure.

[Whoaru99]

Check out this thread. Toward the bottom you will see a schematic, of sorts, showing how the typical 12/24v system is connected.

[Juan Grande]

I'm having problems with my batteries/config. too. I believe I have the wires set up right. I have two deep cycle batteries and a dual bank charger. My trolling motor is 24V.

I called Rapid Sports and the guy told me that one of my batteries might have drained way down over the winter. He recommended throwing it on a regular battery charge to get some juice in it. I guess the bank charger won't charge a battery that is completely drained.

The batteries showed that they were full, but about half way through my last outing (3 hrs) the trolling motor lost lots of power. I have it on level 10 and it barely moves the boat. Wtih moderate use, those batteries should keep that trolling motor running all day right?

The boat and batteries are only two years old. Should I bring them in to have them load tested?