# Marinco vs Battery Tender Trolling Motor Plug



## rssc

I've got a 12v 55lb rip tide on my 1622 Flyfisher. It seems like every year I have to replace the existing deck mount Marinco trolling motor plug. They get corroded without fail. Some of this may be my fault as I leave it plugged in all the time even when I'm not using the TM, which I understand it bad. I also haven't applied dialectric grease which I understand can also help. None the less, it seems like a lot of people have this sort of issue with Marinco TM plugs. Is it something I am doing or are these plugs just prone to corrosion? Should I replace it with another Marinco, a Battery Tender, or another of some sort? I would prefer for the plug to be in the hatch but I don't think that is possible with the design of this skiff.


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## blackmagic1

Battery Tender and don't look back. Put a little dielectric, periodically check behind the plug for corrosion....and unplug it. That's the whole reason you don't have it hard wired anyhow.


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## CaptainRob

Battery Tender is by far the best trolling motor plug I have ever used.


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## rssc

So far seems like the Battery Tender plug is a no brainer. I have 4 gauge running to the existing Marinco plug (with the additional add-on for larger wire). I had to trim back the 4 gauge to get it to fit into the female end. Will 4 gauge fit into the female side of the Batter Tender plug?


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## bobber

rssc said:


> I've got a 12v 55lb rip tide on my 1622 Flyfisher. It seems like every year I have to replace the existing deck mount Marinco trolling motor plug. They get corroded without fail. Some of this may be my fault as I leave it plugged in all the time even when I'm not using the TM, which I understand it bad. I also haven't applied dialectric grease which I understand can also help. None the less, it seems like a lot of people have this sort of issue with Marinco TM plugs. Is it something I am doing or are these plugs just prone to corrosion? Should I replace it with another Marinco, a Battery Tender, or another of some sort? I would prefer for the plug to be in the hatch but I don't think that is possible with the design of this skiff.


 I've been using the Marinco plug/socket for 20 years, never had a corrosion issue because I always turn off the juice between the battery and the socket when not in use. Simple switchable circuit breaker makes it easy.
You really shouldn't charge batteries with a digital troller plugged in to a live socket either.


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## MariettaMike

I'm on my last Marinco receptacle only because I already had it as a backup. Now I have a Battery Tender in my toolbox as my back-up.

Although I will be losing my ability to charge while towing until I rewire my Stealth and umbilical.

The second wire that corroded off in the pic is from my house battery. I guess switching them off would help minimize the corrosion, but the weakest link is actually the rubber stopper for when its not plugged in, and that it also serves as a gasket that isn't very good. I would add some sealant around the plug, and try to find a rubber stopper that plugs the hole better.

FYI: that Perko socket for my nav light has zero corrosion in it and it sees the same conditions as the Marinco TM plug.


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## devrep

don't mount them on a flat deck, mount them on a vertical bulkhead.


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## Whiskey Angler

I feel like the Battery Tender plug is the only plug that is built stout enough to not restrict current when running the TM above 75%. It's design uses thick/heavy elements in the receptacle, and a solid yet foolproof method of fastening the plug. It just make sense. I once had a Minn Kota plug catch on fire from electrical resistance heat buildup....it was ugly. Marinco's design is, admittedly, better than MK's but to me isn't that much different.

Battery Tender...with confidence.


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## tailchaser16

I have used the Power Winch plug for years.


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## permitchaser

My TM plug is mounted on the vertical bulkhead of my front deck. It would be easier if I put it in the middle of the deck but those rust


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## el9surf

That's wierd, I have had Marinco tm plugs on all of my previous boats over the past 20 years and never had corrosion issues. I didn't leave them plugged in when in storage. Aside from that I just kept the ends and inside the female recepticle sprayed with corrosion x every few months. I will say that the twist engagement design of their plug is a pain in the ass.


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## Daz

I've only had this boat (Egret 167) for a year but when going through things last fall I noticed a bit of corrosion and pitting on the TM plug (Marinco 30 amp twist lock shore power type) and sort of "filed it away" that I was going to need to look at it in detail at some point. Every time I had used the little button on the TM base to check the battery level I had only gotten three of the four bars to light up, even after doing a full charge. I figured that either my batteries were going or that maybe all of the lights on the TM didn't all work...

Fast forward -

After seeing and reading this thread I decided to do something about the old Marinco plug and figured I'd try the Battery Tender version. Did a bit of searching and found it on Amazon for about $40 with Prime two-day shipping. Boom. Friday comes and so does my new TM plug. Wow, what a nice looking piece of hardware. So I start my install - Pulled the old Marinco receptacle and found corrosion, especially on the 24v + lug. Nothing surprising though and I continued with the install. No issues siting the new receptacle in the same spot, just had to make a little Starboard bezel (bust out the table saw and router) to cover the old hole and mount the new. I then opened the old male plug and found lots of green. Rather than mess with the corroded screws I cut the wires and stripped them back for the new ring terminals - Oops, black dusty wire. So I cut it back some more, and some more, and still some more. All I was finding was black coated copper with lots of dust. I got tired of this game and just cut off about two feet of wire and replaced it with new tinned marine grade wire. A couple of adhesive lined heat shrink butt connectors and some matching ring terminals and we were finally all set. Why MG doesn't use tinned wire in their TM cables is beyond me.

Anyway, put it all back together, connected the wires, plugged her in and voila! A nice and bright set of LEDs shining back at me. Nope, the fourth LED wasn't burned out and nope. my batteries weren't failing. I just had a shit ton of resistance in the wires from the plug to the TM. The Battery Tender plug/receptacle is a nice system and looks like it'll be a lot quicker and easier to connect in the dark on early mornings.

Thanks for the thread and the opportunity to tell my tale.
We're happy as can be now...

(Just for info, my TM receptacle is located on a vertical bulkhead inside the bow locker)


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## Daz

I've had the BT plug on for about three weeks now and so far so good. It was great this past week to be able to easily reach into the fwd locker and plug the TM in in the dark and not having to grab a light to see which way to turn it.

I'm still happy.


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## iMacattack

I've been watching this thread for a while. Great posts everyone, thank you! Decided to redo the 20 year old trolling motor wiring on my Scout 192. Couple notes, Scout build a great boat. However the decision to foam in all the bloody wiring is insane! The factory trolling motor wire runs from the bilge (three battery setup) *UNDER* the aluminum 54 gallon fuel tank then up the front bulkhead to the starboard side of the front deck bulkhead. This whole section is completely foamed in. So one can not replace the wiring there is no way to pull new wire. So I had to dig out a "boat load" (pun) of foam to run fresh wiring. 

With new wire run I replaced the old MC plug with the BT version. As others have mentioned it's built like a Sherman Tank! The plug is rated to 48V @ 100 AMPS continuous! If you are going to replace your trolling motor plug I highly recommend taking time to look at the Battery Tender version!

Cheers
Capt. Jan

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## bryson

The Battery Tender plug is on my short list of modifications as well. I have the MK plug, which has done alright as far as corrosion goes, but is terrible from a strength standpoint. It's too easy to knock the plug and have it bend the prongs, which has happened on many occasions. They are bent so badly now that it's a pretty tough game getting the motor to stay connected.


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