Thread: New Boat Project

So, you have to start someplace. Some projects will blend together so you need to multi task.
The first order of business is to install a 3 bank battery charger. Two banks will be for the 24v trolling system while the third is for the cranking battery. It is important to note that one bank is usually pre determined for the cranking battery (sticker usually on the cable).

Originally, I wanted to mount the charger up by the two TM batteries so that I only had to make one run back to the cranking battery. Unfortunately, there isn't enough room in my rod locker or in my battery bank bay (located under the rod locker). My particular unit requires about 8 inches of clearance around it. It will be installed next to the cranking battery and two extensions will be run to the battery bank.

The picture below shows my fish tape located in my battery bank. In order to get to a pull through locations I had to remove the batter tray (4 screws) and then drill out the pop rivets for the battery box. Once this was removed there was a chase hole in the cross supports that allowed me to run under my fuel tank and back to the rear of the boat.



Tonight I will clip the wires on the charger, install my extensions and pull it to the box. Note that the manufacturor always tells you not to clip the wires. They do this for two reason. One: they want to sell you an extension cable for 40 bucks. Two: they want to make sure you don't bypass the inline 25amp fuses. I have done enough of these to know that you CAN clip the leads just make sure you clip them behind the fuse. You will splice in your wire extention and then splice on the fuse and battery terminator. The fuses should always be within 12 inches of the power source.

When dealing with wire, it is important to always get the correct size.
While doing my battery charger install, I also want to start planning for power to my helm fish finder, bow fish finder, structure scan unit, and marine radio.
Although I could utilize the acessory swith located at the helm, this has proved in the past to be a bad idea. One reason is the wiring utilized isn't big enough to support the draw of the above mentioned items. The second is the cross talk interference you might get (big deal with a fish finder). I personally do not like to have to flip an accessory switch to ensure my electronics are on. I am also not a person that leaves this stuff on to draw down my cranking battery.

You do have some options however. Most boats usually come with a bus panel located under the helm. This panel gives you a few screws to be able to jump power and ground your unit. Sometimes however, the panel is behind the accessory switch thus you must throw the switch to power the devices. Another option is to run wires from each device back to your main battery (in my case it would be 4 runs). You do NOT want to wire to your trolling motor batteries. Although it is convienant, the amount of interference will far outweigh the short power runs you make. Do it right the first time.

Another option is to install a secondary fuse panel. These can be purchased from many outlets and are available in many configurations. The most common being six and 12 circuit boards. Cabelas seem to be one of the main shopping choices for alot of people and they offer one from blue sea. Understand that they do not provide documentation on these things. Basically, they are 100amp units and you cannot utilize any more than 30 amps per circuit. They use a blade style fuse which will allow you to clip the inline fuse that comes on most fish finders and other appliances.

A couple notes: 1. since you will be running more equipment from the cranking battery, it is always advised to upgrade to a bigger battery (this will be my case). The other option would be to run two 12v batteries in series to ensure you have enough volts and amps. Always remember to use the same size batteries when running parrallel or in series.

2. Always make sure you have the correct size wire for your application. In the above scenario with the blade style fuse panel you will do the following: Measure the amount of wire you will need from the battery to the mounting location and then double it (DC power allows current to flow from the battery to the appliance and then back to the battery). Once you have the number of feet, you can use the chart provided to figure out what gauge of wire you will need. Typically, major appliances (like a bilge pump) would require 3% voltage drop while a fish finder would require around a 10% loss.


In my application, I would be placing the fuse panel 10 feet from the battery. If I double that, my number is 20 feet. If you look at 3% voltage drop, then I would need 2AWG wire gauge to properly power the panel. This would more than likely be what I would use (If I go this route). Being as I would be running non criticle elements from the panel, I could use the 10% calculation and get by with 4AWG.

Do it right the first time to avoid tearing things apart again. I like a clean appearance so I hide my wires like the factory.

Stay tuned for more to come. I'll get into fish finder mounting, transducer mounting options and ideas, trolling motor mounting (with removable mounts), RAM mounts...... I'll try to cover it all as I go along.

Before I get started I just want to give a recommendation. Whenever you are putting hardware into a boat, make sure to use stainless steel hardware. You may pay a little extra for them but your money will be well spent. You won't have to worry about rusted bolts in five years when you go to change out something. I buy them in bulk and save all the extra stuff that comes with new products I order.


Tonight started with the battery compartment. The main battery was too small. In this picture you will see the original configuration.


Take note of the wire tunnel in the right corner of the photo.

Because I was putting in a size 30 battery, I needed to reconfigure the layout. I removed the old battery box and then removed the wire tunnel cover. This boat has alot of rivets and I drilled them out. Because the layout changed, I had to rethink the mounting of my charger. I mounted it on the bulkhead, scribbed the wire tunnel cover, cut it with a dremmel, and installed with stainless screws. I then put the new batter tray and battery in.


When making my wire connections for my charger extension, I always utilize shrink tubing. I then overkill it buy taping the ends.


After both sets of extensions were done, I attached to my fish tape and pulled them through to the trolling motor battery compartment. I terminated the ends with the required inline fuses, wrapped the wires in a protective casing, and installed in the battery boxes.

I wanted to install a new inline cicuit breaker but the configuration of the trolling motor battery compartment left little in the way of bulkhead mounting.


To combat this issue, I nothed out both boxes with a dremmel. This would also be when my trusty dremmel of more than 10 years decided it was time to go to dremmel heaven. I finished with tin snips. You can now see the circuit breaker mounted to the bulkhead.


Finished (minues another battery). When running 24v systems in parallel (or 12v in series) make sure you use the same size batteries. I have another one on order.

Finished (minues another battery). When running 24v systems in parallel (or 12v in series) make sure you use the same size batteries. I have another one on order.

Hey rich , you might want to switch that around , 24v in series and 12v in parallel. Nice job so far!!

Thanks Kevin. I was a little irritated this morning while writing that as it was about the 20th attempt to update my post! Originally, I got two batteries for my trolling motor. Once I realized that bigger is better, I upgraded my cranking battery with one of my TM's. I have the other on order. All I have to do is drop it in and hook the wires up. Cabelas has them for about 100 bucks off. Plus free shipping to my door!

The nice part about the winter is that I am not in a hurry to get it done and get on the water. I can take my time.

What batteries are you using? I need new for my boat. I've been putting it off.