Boat battery wire smoking!

[Skunkedagain]

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. I will also post this question on iBoats but there are some smart folk here and have helped me many times with boat stuff.

[civicrr]

so, is this a Perko switch? if so, you should have the positive from one battery to one termimal. the positive from the other battery to the other terminal. the other terminal, labeled common, is typically connected to the outboard positive.

how many batteries do you have on the boat? two or three? if only two, are you using your starting battery as one of your 24v trolling motor batteries?

[acm95301]

Crossed connection somewhere...get thee to a boat repair shop...your wiring may now be damaged...i'd disconnect your batteries now.

[civicrr]

Crossed connection somewhere...get thee to a boat repair shop...your wiring may now be damaged...i'd disconnect your batteries now.

probably the best advice @ this point.

[Skunkedagain]

I have 3 batteries total. One for the motor start, two for the trolling motor. I do believe (upon googling perko switch) that it is a perko switch. The perko switch is only connected to the two trolling motor batteries, and it was told by the person who sold me the boat to switch this perko to 24V to use the trolling motor, and "charge" to charge them. I seem to have to charge the starting battery with a plug in charger and the trolling motor batteries with a plug coming from the on board charger.

[blkdog812]

the perko switch should be used to cut power from the batteries or to allow power from the batteries to the accessories. its not made to be used to run a charge thru for the batteries.
each battery should have its own lead from the charger. something is not wired properly. is you cant find the proper way to wire the perko switch off the internet, take it to someone who can. until then disconnect the batteries

[Skunkedagain]

Do I need a perko swtich in the first place? I have a separate battery that I charge with a charger for my motor. I then have two batteries (wired or 24v) for my trolling motor. Can't I just have my onboard charger charge the two trolling motor batteries without a perko switch?

[swordfish]

The Perko switch in my experience was used in salt (big) water to select batt. 1 or 2 for crank batts. for a spare or for power shut off.

[BassManDan]

I can say without contradiction, smoking battery terminals are BAD!

Sorry, couldn't resist.

I'm with Skunked, why do you need a perko switch? Should be a separate harness for the trolling motor battery(ies) and a separate harness for the cranking/accessories battery(ies)

[civicrr]

Three batteries is the best way to go. You need to run the two trolling motor batteries in series. Battery 1 positive to 50 amp breaker. TM positive to other side of breaker. Battery 1 negative to Battery 2 positive. Battery 2 negative to TM negative. Make sure to use heavy gauge wire - 6 gauge is preferred. I would seriously think about replacing rather than reusing the smoking wires!

A three bank charger is the most convenient way to charge the batteries. If I understand you correctly, you have a two bank charger with each TM battery connected to a bank. Are you counting on the outboard to keep your starting battery fully charged?

If you only have a two bank charger connected to the TM batteries, you really should make sure the starting battery is fully charged with a shore charger. Hopefully, you can do that right after use. Getting the batteries back to full charge & keeping them there, is the best way to get a long life out of them.

Some guys like a to run the positive lead from the outboard thru a Perko. That way they can shut all accessories down that run thru the circuit - bilge pump, etc. I've come back to storage only to hear my bilge running - lucky it didn't get burned out. I also turn off the switch when traveling - keeps people from messing with the tilt/trim.

[jimmy87]

I had a boat that had a 12 volt trolling motor. It had a preko swith to switch to a spare battery when the trolling motor battery wore out.

3 batteries. 1 for the cranking motor. 1 for the trolling motor. and a third on the preko switch in case no. 1 troll motor battery wore down.


in your case you have three batteries. correct?

if so, you would need a 3 bank charger to charge all your batteries. you can not charge 2 battiers off one bank.


hope this helps.

[Skunkedagain]

As usual, thanks to all of you for trying to help!

Probably tuesday I will attempt to re-wire everything without the Perko switch. I have no idea why it was there, I can't seem to even venture a guess, but it is on par with the rest of this boat and if the track record of the guy I bought it from is any indication, this was a complete jerry-rig. I just hope it hasn't fried anything.

[blkdog812]

leave the perko switch in, just get it wired the right way. in the event of a battery drain or worse yet an electrical problem, you can kill power from the batteries.
how many stops are on the switch?
is it an off/on.......or is it.........off- 1-all-2
do you have a breaker switch on the wires for the trolling motor?

[Skunkedagain]

From some research, i believe that my batteries/charger set up requires the perko switch to cut the 24 volts so my charger can charge the batteries-

"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"

So i'm now hoping it is a bad wire or a bad perko switch, and hopefully I can replace these myself and get back in the water. I can't afford to put too much more $$ into this POS so I can't take it to a shop.

[Oldschool]

Disconnect the trolling motor battery terminals from the posts. Recharge each battery with an external charger, so you know each battery is good. One problem with deep cycle marine batteries is each cell is independant 2V. If one cell is bad then the good cells continue to recharge the bad cell and your onboard charger continues to run without stopping, over heating the charging wire.
If you smoked a wire, burning the insulation, the wire may short out at any time, replace it. Fire caused by electrical short is ugly in a fiberglass boat.
The onboard battery charger should have a separate bank wire to charge each 12V battery, 1 common ground is normal.
The heavy duty 40 to 50 amp battery switch should be wired to the cranking battery only and switched off when charging the cranking battery or the trolling motor batteries.
The switch protects your 12V circuit for everything other than the trolling motor.
Does the trolling motor have a 12V & 24V switch? Make sure the trolling motor switch is in the off posiiton when charging the batteries or unplug it.
Tom

[civicrr]

What brand & model of charger do you have? How old is it? Have you looked up the manual on the internet? I can't remember if you said how many banks.

I am assuming that you have a marine specific battery charger. If you do, it should have a positive & negative for each bank (battery). You should not have to disconnect or switch anything to charge the batteries other than making sure the TM is turned off/disconnected. Almost all of the chargers have some sort of diagnostic display. Does the display make you suspect a bad battery?

[Skunkedagain]

Honestly, I think the original owner of this boat just jerry rigged it..possibly now knowing that the battery charger already is capable of charging all 3 batteries...

I now know exactly what caused the smoke/hot wire...the perko switch was wired to link the two trolling motor batteires, and then provide a negative to negative link throughout all batteries, perhaps thinking that he needed to do this to charge all batteries, I don't know.

I have a guest 2623..which is capable of charging both my trolling motor batteries in 24V and my starter battery...so it begs the question WTF was the original owner doing with this potentially dangerous set up...as when you switch the perko switch, as brief as it can be, at some point the way he had it Battery A - was connected to Battery B + AND battery A + was connected to Battery B - as the switch slides to the next setting...and it was evident when I took the switch apart and noticed melted metal spot where the contact touches two seperate contacts...thereby creating the two batteries linked the way just described..usually brief but it stuck..and that's when the wire smoked and heated up...not safe.

[swordfish]

It's good to have friends and info. To me this makes this forum work....for the cause and care for the sport and what comes along with it .........

[Skunkedagain]

Absolutely, lot's of people here take the time to help someone they don't even know. I myself totally appreciate it