# Different Batteries for TM and FF? ? ?



## Jezreel (May 1, 2017)

OK, I am SO new at this boat stuff! I have read a few threads that reference the interference a FF can get from the TM, if you have them drawing from the same battery. Or at least that's what I think I am reading. I am SO close to finishing my Tracker 1542. I just need to do the electrical stuff. I am waiting to screw down the front deck til I get my wiring done. I am planning on attaching my transducer to the TM. Do I need to have separate batteries for the TM and FF to eliminate any interference? I will most likely have a bow and stern light, and bilge pump at some point. 

Thanks.


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## stinkfoot (May 1, 2017)

This is what I use. You can buy from fishfindermounts.com but you could also use a burglar alarm battery for a cheaper option. I like this because I don't have to pack a giant automotive battery when drifting rivers in my pontoon. It fits in the pocket.


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## jethro (May 2, 2017)

I have my Humminbird Helix 5 and my Minn Kota PD50 bow mount hooked to the same deep cycle battery and there is no issue at all. I had the same concerns as you but there is no change at all in the feedback I recieve through the sonar when I'm using the trolling motor.


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## Jezreel (May 2, 2017)

Thanks for the replies, guys! I like the looks of that small battery, and the website says it should get 30-40 hours off of a charge, which I certainly wouldn't need. And inexpensive too!


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## onthewater102 (May 2, 2017)

I have a Minn Kota Terrova 12v 55# on a 1436 and it interfered badly with my Humminbird 798. I did as others here have suggested and added a small alarm/computer backup battery exclusively for the fish finder and it stopped the noise.

If you're wondering if you're getting interference it is very obvious - your image will get all distorted when you've got the trolling motor under momentary power and the distortion will come and go as you press and release the power button. Cheapest option is to see first if you've got an issue, then buy the solution.


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## lovedr79 (May 3, 2017)

i did not get any interference using the same battery. motorguide TM and hummingbird FF. try it and see if you get interference. if you do add another battery.


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## wmk0002 (May 3, 2017)

As others have said try it first just to see. I would also try to route the wiring apart from each other too....like run the TM wire up the left side and FF wire up the right or up the middle under the floor/deck. Also make sure you use appropriate wire size and marine quality wire.


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## Jezreel (May 4, 2017)

Great info guys. It certainly won't hurt to try the one battery first, and then go to two if needed. I have decided to put 2 hatches on each side of the deck. The big battery will go in one of those hatches, so I don't have to run wire all the way to the back. Hopefully, the shorter run for the wires will decrease any chance of interference. 

My set up will look similar to this, but with smaller hatches, and the seat plate just in front of the middle seat. This picture was borrowed from FishinFL's build page. Just wanted to give him credit for the pic and idea.


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## richg99 (May 4, 2017)

You already have great advice here. I can't add anything other than...when you are running wires, run a few extra ones. They will come in handy later.

richg99


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## Captain Ahab (May 4, 2017)

I use a separate dedicated batter for FF bilge, lights etc. The extra battery is also a spare if one of my other batteries dies on me as I run some electric only lakes 

In total I have a batter for the front TM the rear TM (and starter for outboard) and a third for everything else


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## Jezreel (May 5, 2017)

Yes, I was planning on running extra wires but was curious what gauge to run. I can't imagine they would be for anything but lights, bilge pump, 2nd FF or something of that nature. So what gauge do you think the extra wires should be?


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## jethro (May 5, 2017)

Jezreel said:


> Yes, I was planning on running extra wires but was curious what gauge to run. I can't imagine they would be for anything but lights, bilge pump, 2nd FF or something of that nature. So what gauge do you think the extra wires should be?



If it were me, I would run some fairly hefty (maybe 12 or 14 ga) to a small fuse panel/junction box, then your accessories can run off 18-22 ga wire.


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## Stumpalump (May 5, 2017)

I always run electronics like fish finders and radios directly to the battery. Do not pass go! Gotta remember to turn them off. Who ever said 4 or five wires going to the battery terminal needs a seperate fuse box is feeding you a line a BS. No better connection than to the batt and most of those electronics come with an inline fuse. Keep it simple. Run a nice longer stainless bolt thru your batt terminal and pick up a pack of larger connectors to go over it. Everthing is right there. Easy to see. Hit the terminal with a shot of spray lube once in a blue moon.


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## gnappi (May 10, 2017)

My last boat sold 10 years ago, I never had interference between my various instruments. That went away with LORAN. 

That said, I'm surprised this subject comes up. I would think "snake oil" electronics companies would come up with steering diodes and filter array for "sensitive" electronics. 

Nowadays my needs are few (but growing) but I expect marine stuff has gotten only better in the years since I was offshore often.


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