Using a 24 volt system and 12 volt system at the same time.

[mjbuck]

I just purchased a MinnKota Terrova trolling motor. It has to be run off 24 volts. No problem, I have that figured out from the MinnKota web page, which shows how to connect the system specifically for the model of trolling motor I purchased. I am going to use the "Connect-Ease" quick-connection kit for convenience with these batteries and on-board charger. My two batteries for the 24v set up are in the front 1/3 of the boat and my third battery (12v only) is in the far back. The back single battery will be used to run 12v only. ( It already has a couple of items connected to it, INCLUDING MY MAIN ENGINE FOR STARTING). I will run the new trolling motor off the 24v battery set up in the front, but I also need to connect three or four other 12v items to the front batteries (24v setup). These include a Marine Radio, Trollmaster trolling control throttle, a Fish-Hawk speed and temp system and a fish finder. These items are all in the front of the boat and for convenience I do not want to have to run the wires 20 + feet, all the way to the back 12v only battery unless I have no other choice. I might not have to connect the fish finder to the battery, as it is will be connected directly to the Trolling motor as they are designed to work together. But, I am not sure if the fish finder draws power directly from the trolling motor through their factory connector plug, or, do I need to connect the fish finder to the battery separately. (I just purchased all this stuff and have yet to sort it out and set it up). So, again, my two batteries up front are going to be used as a 24v system. I want and need to connect 12v items to these batteries or to one of these batteries. Can I do this? How do I do this? I have been researching this off and on over the last two days and there seems to be so many opinions on the net that I came to Iboats (again) to get the answer. Thank you.

 

[ondarvr]

Yes, just connect the 12V items to one battery as you normally would, don't connect it to anything else though.

 

[mjbuck]

After reviewing this exact topic for many hours and becoming more confused with each I read to other similar posts to mine, I have decided to go this route. Even though I have room for only three batteries on my boat, I am going to add a 4th one. It will be most likely under the passenger dash, out of the sun or rain, but near the feet of the passenger. I will make sure it is strapped down for safety and on a battery tray. I will use the two batteries connected in the 24v set up for just my trolling motor. I will leave the far rear battery connected to what it is currently connected to (powering) and connect my up-front electronics to this 4th battery. So, unless you have a short explanation or a quick approach to answering my question above, please save yourself the time of explaining. I will leave the topic open, as there might be someone with an easy and uncomplicated approach to my question. There are many answers to other similar posts, but many are so complicated, they were over my head. In additon to that, some seemed to contradict each other. Thank you.

 

[ondarvr]

Not sure what you're confused about, just connect your 12 volt stuff to one of the batteries in the 24V system, positive and negative just as you would to any other battery, but don't combine those items with any other power source. You still have a 24V system and a 12V system in one two battery set.

 

[mjbuck]

I understand what you are saying. I also read numerous posts on the set up you are describing. The biggest issue when running electronics with your trolling motor batteries is the potential for interference. The other is by drawing more juice from one of the batteries (using it to power 12v electronics while also using it power the trolling motor) that battery discharges at a faster rate than the other. I spend long days on the water I don't want to end early because I am running one battery down dead. The 4th battery will work just fine. In my earlier post, my intentions were to put this battery in the passenger side foot-well, but I completely forgot about a hidden compartment right next to my battery compartment that will hold another battery. This compartment is in the front 1/3 of the boat, so it is a short run for the wiring. It is vented in two locations and I am thinking that is what this compartment was intended for. I was using it for basically nothing and a 4th battery will fit in there fine. It is water-tight and like I said, ventilated, so problem solved. Thank you for your time though.

 

[aaron42]

You can't run the 12 volt devices from one battery as it will drain that battery faster than the other one and give you problems when recharging. You need a 24 volt to 12 volt converter. I use this one for running the radio, depth finder, and nav lights on my sailboat. https://www.amazon.com/gp/aw/d/B003P...gsL&ref=plSrch

 

[ondarvr]

You can run them like this, when recharging with the correct charger it makes no difference, each battery will charge as needed. Is it the best way to do it...no, does it work...yes.

 

[fishrdan]

I am going to use the "Connect-Ease" quick-connection kit for convenience with these batteries and on-board charger.

That system doesn't look all that "easy" to me, just a bunch of Anderson plugs with wire and terminals attached. Check out genuinedealz(dot)com for the wiring and terminals, they could make this system for you with custom length wires to fit you boat, probably cheaper or the same price.

Personally, I wouldn't recommend the Connect-Easy system as they are pulling multiple 12V accessory connections off the 24V bank, high side and low side, 0-12V and 12-24V. Cross a ground between the batts and you'll BBQ equipment. I get why they are doing it, to help balance the 12V accessory power being drawn off the 24V bank, but it's a disaster waiting to happen, even if it's fused.....

Check into Marinco 12/24 plugs and receptacle, much easier solution and can convert 12 to 24V by simply connecting the correct plug into the receptacle. You will still be swapping plugs, but it will be on the exterior of the boat and not opening hatches and monkeying with the battery wiring. I use the Marinco system and can plug 24V accessories or 12V accessories in to the outlet (trolling motor, fishing lights, charging, etc...) If you want 12V accessories running off the 24V bank, still run them direct (fused) off 1 battery, the low side 0-12V in the 24V bank.