24 volt trolling motor wiring, and battery mounts

[Sutty]

I bought a 1850 fishawk without a trolling motor. I bought a 24 volt Minkota and need to install it. The boat does have the plug recepticle with cables going to the battery compartment, they are marked as 12/24v so I think I am ok there. I need to figure out how to connect the batteries together to make them 24 volt and I need to install some battery holders. The compartment is next to the console and you need to open a second door that is basically going down to the hull. Not sure I really like the design since water will be going past the batteries when it rains etc. Anyone else have an 1850 and did you change where you put the batteries?

Oh and can I still connect my bow mount depth finder to the trolling motor batteries somehow or should I run that back to the starting battery?

[dfv87]

DO NOT run your locator to a 24V battery set up unless it says it is ok, which most likely it is not. You could fry it. The wire should be run back to the starting battery. As for 24 set up you can do a search of the subject but I believe you just run a wire from - to + on the other battery and you have 24 v juice.

[Sutty]

I should have clarified. I was wondering if you could put some kind of reducer in to bring it back down to 12 volts for the fish finder. Probably easier to just run it to the starting.

[marine_man]

I'm not sure on a reducer, but you really want to avoid connecting to the trolling motor batteries for your locator due to inteference from the trolling motor showing up on some locators.

marine_man

[Whoaru99]

Generally, when a boat is configured for 12/24 volt wiring, you connect the batteries to the leads provided for them - one pair of leads (+ and -) to the + and - posts on one battery.

How you wire plug that goes on the trolling motor power wire (or other accessories) is what determines if you supply 12 volts or 24 volts to the device.

For other accessories not going to a plug-in, don't worry, it's really easy. Just wire them to any single 12v battery. As long as you connect the + and - lead of your depth finder to the + and - posts of ONE battery, you will only get 12 volts.

As noted though, sometimes you can get interference if you connect to the battery(s) used by the trolling motor.

I connect all my accessories to my starting battery that is a dual purpose starting/deep cycle battery of larger capacity than normally just for starting.

[Umma Gumma]

I have a follow-up question on the same item. I just purchased a 24v Minn Kota. I have a Marinco plug. When I pull it apart, it appears that the ground stays in the same hole, but I use the 24v hole now instead of the 12v. This seems obvious, but the book only mentions 12v motors and 12/24v motors, not straight 24v. It says to hook the 12v up to the 12v and the 24v up to the 24v for a 12/24 setup. Should I hook up the ground to one hole and the 24v to the 24v hole?

[marine_man]

Your plug is probably internally jumpered between the ground and batteries to make 24V.

So, connect the ground wire on the trolling motor to the grounded port and the other wire on the trolling motor to the 24 volt port and you should be in good shape.

marine_man