Boat battery wire smoking...HELP!

[apaseman]

Ok, I apologize for the lack of information, but I'll give you as much as i can..

I have an on board charger...but not sure if that has anything to do with this..

On my boat near the batteries there is a large knob that I was told to turn to 24 volts for running my trolling motor, and turn it once to "charge" for charging. Today when I went to charge my trolling motor batteries, as I turned it, there was now smoke coming from battery A's positive connection, and the wire running from this knob was very hot.

I do not really know exactly what this knob is responsible for or what you call it. I'm assuming it is a device which links my two 12V batteries to run 24V. I've taken it off and inspected it. This knob has 3 wires coming off it, two that run to battery B and one that runs to battery A.

Any insight as to what is happening here would be great...just one more thing that has gone wrong with my old boat. I'm lost, I don't know if a wire is bad, the knob device is bad, or what...and can't run my boat until I can figure this out.

 

[chifloater]

Re: Boat battery wire smoking...HELP!

Is the setup you have new? or has it changed from before? If not then I can tell you that you have an issue with poor connection. It may be from corroded connections, frayed wiring, or poor contacts in the knob itself...I would clean all connections replace frayed wiring and clean those contacts...The problem now is what if anything was damaged.....good luck hope i was some help

 

[Rocky_Road]

Re: Boat battery wire smoking...HELP!

Hot wire=high resistance=dirty, or loose, connections.

If this were mine, I would be cleaning ALL connections...especially the battery post leads. Use a dab of dielectric grease when you reconnect everything.

Start there...and report back to us!

Happy boating!

 

[fishrdan]

Re: Boat battery wire smoking...HELP!

Need more info; what type of switch it is, how many batteries does the boat have, how the batteries are connected, what gauge of wire is being used, exactly what were you doing and was anything running when the switch was flipped.

If the positive battery lead was smoking when you flipped the switch (nothing running, just flipped the switch), I'd say the switch either connected 24V to your main battery eek or connected 2 of the batteries reverse polarity eek. Bad situation either way. I don't think I've seen any type of switch that can parallel batteries for charging, and then, break the parallel connection while at the same time connecting the batteries in series to get 24V for the trolling motor.

Was anything changed in the boat recently, new battery, wiring? Has this worked before?

 

[Bondo]

Re: Boat battery wire smoking...HELP!

This knob has 3 wires coming off it, two that run to battery B and one that runs to battery A.

Ayuh,... The battery terminal that was Smokin',..?? It's corroded, Bad...
And,...
A 3 wire switch should have 1 wire from each battery,+ the 3rd wire goes to the Load...

 

[apaseman]

Re: Boat battery wire smoking...HELP!

Unfortunately, I do not know very much about wiring. What I do know is I hooked it up to new batteries exactly the same way it was before I replaced my batteries, and it has run fine after that with no issues (known). The wires coming off the knob (wish I knew what this thing is) look old...so maybe it's possible that it's just bad wire. The smoke wasn't coming from the battery itself, looked more like the wire at the connection, and the wire itself was hot, so I do not believe the problem is with the battery.

I do not know the gauge of the wire..it's about as thick as my pinky.

When I got the boat, this knob device had three wires coming from it. What exactly is "the load"?

 

[apaseman]

Re: Boat battery wire smoking...HELP!

I think I found out the name of this "knob device". I've been told it's probably a Perko Switch.

 

[blairjbyrd]

Re: Boat battery wire smoking...HELP!

It could be a bad wire too

 

[fishrdan]

Re: Boat battery wire smoking...HELP!

The Perko switch only deals with the + wires from the batteries, and then the engine or outboard + connection. Old Perko switches had the "combine" lug, and switch setting, marked as Com (or comm, can't remember). I've heard of people getting this mixed up with common (IE: ground), and when the switch is flipped, it creates a direct short to ground, this would be like placing a wire across the + and - battery lugs. The switch should be wired as;

#1 to the start battery + terminal
#2 to the other battery + terminal
"Com" (Both or 1+2) to the engine or outboard's starter (load)

Pinkie sized battery cable (#1 or 2?) takes a LOT of current to get hot and smoking, and to me, this sounds like the battery is getting shorted directly to ground. Check that your wires are hooked up properly, the cables are in good condition,,, not chaffed or touching metal.

If you were starting the engine when the cable started smoking, then I'd suspect a loose connection, corroded cable. But, since the cable smoked when the switch was flipped, something was drawing tons of current down the wire,,, when the switch was flipped.

Where is the "Com" terminal of the battery switch connected to and how does that cable look?

(BTW, I google imaged for an old style battery switch (perko) and they only showed the new style switches with the "common" lug marked as 1+2 or Both,,, something that makes a whole lot more sense than Com.)

 

[apaseman]

Re: Boat battery wire smoking...HELP!

Hmm. It's all kinda confusing for me as I know nadda!

Honestly? I don't think any of the wires were connected to any starter, but one to one battery, and two to the other...my starting battery is not part of this equation. It's just my two 12V batteries set up to run my 24V trolling motor. I did change to new batteries, but I hooked up the wires exactly as they were hooked up. It's in the realm of possibility that the guy I bought the boat from didn't hook things up properly...I was just showed to turn the perko to "24V" when running the trolling motor, and to "charge" when charging. These were just stickers he had on the perko switch...not something the perko switch had there already.

At this point, I'm wondering why I have the perko switch in the first place? Can't I just hook my on board battery charger to my batteries, and my trolling motor to my batteries without the need of this perko switch??

 

[fishrdan]

Re: Boat battery wire smoking...HELP!

If the onboard charger has enough outputs (IE 2 or 3 outputs), then it can be connected directly to each battery, separately, and there is no need for the Perko switch. I can see why a Perko switch would be used, to connect 1 (one, 12V...) of the trolling motor battery bank to the engine, so if the main battery died you can use one of the trolling motor batteries to start the engine. But,,, you are not going to be able to charge both batteries in the 24V bank with a single output 12V charger, without first breaking the series connection between the 2 batteries. (It's possible, but not without some weird wiring and understanding what needs to be disconnected and then switched before charging) What brand/model of charger do you have?

The only reason for a battery switch (perko) is to select which battery you want to use, or combine both of them at the same time for more power or charging both batteries from 1 source. Which batteries are connected to the Perko switch, just the trolling motor batteries? How does the trolling motor connect to the batteries to get 24V, straight wired or is there a plug? If a plug, how many pins in the plug. I'm wondering if the PO installed an odd setup for charging the batteries that involves a battery switch...

Question on the battery cable you said was "as big as you pinkie finger", where do these battery cables connect, at each end? Battery cable that big is meant for heavy loads, as in starting an engine, not really needed for a trolling motor. Most Trolling motor manufacturers recommend either 8 or 6GA wire for battery connections, it's about as thick as a pencil, maybe a bit thicker.

I think you will need to do some digging and see how everything is connected, and how the Perko switch figures into the picture.

(BTW, I have a Perko switch connected to one of my trolling motor batteries,,, as a backup for the start battery.)

 

[smokeonthewater]

Re: Boat battery wire smoking...HELP!

there is also another way this can be hooked up.... it may be wired to connect pos on batt1 to neg on batt2 for 24 volt across pos batt2 and neg batt1.... then with a flip of the switch it could connect neg on batt1 to neg on batt2... this along with an acr, diode or another switch between the pos terminals would allow for a single bank charger to charge both batts..... This is only speculation but if the acr, diode or switch was improperly connected or otherwise not functioning it could explain the hot wire

If this is actually how it is connected my recomendation is to ditch the setup for a dual bank charger.

 

[fishrdan]

Re: Boat battery wire smoking...HELP!

there is also another way this can be hooked up....

I see what you are talking about, and that would work (questionably), and it might be what apaseman has... But, the problem is, if the switch was inadvertantly flipped to COM (BOTH or 1+2),,,,,,,,,,,,,,,,,,,,,,,,,,, the + and - terminals of batt #2 would be shorted together Causing the battery to dump itself and smoke the wires.

I guess that would explain why it worked at one time, but smoked the wires when the switch was flipped (probably into the wrong position).

 

[apaseman]

Re: Boat battery wire smoking...HELP!

there is also another way this can be hooked up.... it may be wired to connect pos on batt1 to neg on batt2 for 24 volt across pos batt2 and neg batt1.... then with a flip of the switch it could connect neg on batt1 to neg on batt2... this along with an acr, diode or another switch between the pos terminals would allow for a single bank charger to charge both batts..... This is only speculation but if the acr, diode or switch was improperly connected or otherwise not functioning it could explain the hot wire

If this is actually how it is connected my recomendation is to ditch the setup for a dual bank charger.

Oh! I bet this is it! Because the perko's 3 wires were: one to Battery A Positive (this was the HOT wire), one to Battery B Positive, One to battery B Negative.

The only funny thing is I am 95% sure the battery charger is a duel bank charger...at least it has wires connected to both terminals on both batteries. I've been cleaning up after the guy I bought the boat from ever since I got the boat home, so I would not be surprised if this whole wiring set is completely wrong. (having the perko to charge two batteries despite having a duel bank charger)

 

[willamettejeff]

Re: Boat battery wire smoking...HELP!

You may have a dual bank charger, but unless the outputs are fully independent of each other, then the charger will have a common (ground) between both charge sections and this will be connected with one of its positive outputs when the batteries are connected in series to make 24v. Would need to break the series connection for charging, hence the need for the switch. All depends on what charger you have. Suspect you turned the switch to or through the 1+2 position, which would cause things to smoke big time.

-- Jeff

 

[apaseman]

Re: Boat battery wire smoking...HELP!

Sounds like I need to investigate my battery charger...

While I can't rule out "user error" I'm 99% sure that I did not turn the dial to the wrong position. Would a bad wire or a faulty perko switch also be an option? At this point, I will assume the perko switch is needed as that is what was on my boat...so now I have to try to figure out what is wrong with that assumption.

 

[willamettejeff]

Re: Boat battery wire smoking...HELP!

If it was me, I'd dump the switch and spend my money on a charger that has independent outputs. Some of those even automatically handle 12v & 24v systems. With a two bank one of them you would be able to charge your 12v starting battery and 24v trolling battery bank at the same time.

-- Jeff

 

[apaseman]

Re: Boat battery wire smoking...HELP!

If my boat was gonna be a long term boat, I'd just assume get that new charger. However, once my wife makes it through school and finds a job (1 year) I plan on selling it and buying a newer used boat. This one is a '87 and it's been good money after bad. I just want to fix the problem in a way that makes it able to get back on the water, so I'm hoping someone can chime in and hopefully it's possible that it's a bad perko switch (or better yet) a bad wire from the perko switch to the battery.

 

[apaseman]

Re: Boat battery wire smoking...HELP!

OK, so upon some investigating, I have found out a something.

I replaced all three wires coming from the perko switch. Hooked it back up. Everything worked. Until....

Testing, turning the perko knob, back from 24V to "charge". THen, once again, I turn the knob of the perko from 24V to "charge" and...smoke from Positive battery B terminal. This did not happen at first..so I took the perko switch apart, and it looks like the switch might get stuck a bit when you rotate the knob and at some point, all three contacts are touching rather than two at at time, so I am assuming that this is what is causing the wire to heat up and smoke.

I am off to the store to see about a new perko switch. $20 in wiring I guess wasn't needed, but alas now I have brand new wires for my future new perko switch.

 

[apaseman]

Re: Boat battery wire smoking...HELP!

Problem solved

So, talking to the guy at West Marine, he said I had no reason having the perko switch I did, and that all I need is a simple on/off switch between my wire that goes from positive Battery 1 to Negative battery 2 (so i get 24 volts out of my two 12V batteries).


I thank all of you who took the time to respond to my problem, i've learned a lot from you. Now, I'm gonna make a new post about my wiring set up as I'm a little confused as to why it is set up this way.