# Battery terminal post melted? Anyone seen this b4?



## nicferrante (Oct 10, 2007)

We have had consistent battery issues on our Islander28. We have a Yanmar engine and (we think)the original standard battery charger. We are on our second set of batteries, but the third time they have been depleted. This time the terminal posts melted. Has anyone seen anything like this? I am not sure where to start the investigations...the charger? Any insight would be appreciated.


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## sailingdog (Mar 19, 2006)

If the terminal posts are melting, you either have a serious short someplace or some badly corroded battery cables, more likely than not. My bet would be the cables are badly corroded. A lot of boats used non-marine grade welding cable for the battery connections, and if you cut the ends off the cable and peel back the insulation, I am willing to bet that the copper there is badly corroded and black with it.


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## btrayfors (Aug 25, 2006)

Nic,

Sounds very much like you have a *serious* problem, and one which could easily cause a fire.

I agree with dog, but think you need to look further than the cables as well. A looksee by a qualified marine electrician would be a good thing to do; well worth the cost.

I think you're looking at replacement of the batteries, the cabling, the battery charger and, possibly, the regulator for your alternator.

This is what I'd be thinking of doing if it were my boat. Piecemeal changes will almost certainly continue to give you grief. If you make the investment in correcting the whole system, you'll not have to worry for many years to come.

Bill


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## Maine Sail (Jan 6, 2003)

First off there should be fuses at the battery terminals to prevent any sort of short melting the lead posts. Second melted battery posts are cause for concern!! 

My guess is that you may have a ground short somewhere? Perhaps a pos cable is touching bilge water and has a cracked jacket or is worn through and barely arcing on the engine block..??


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## sailingdog (Mar 19, 2006)

Btrayfors-

I'm not saying he shouldn't check further, but that the battery cables would be the first place I'd check.


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## hellosailor (Apr 11, 2006)

Nic, it takes a lot of heat (extremely high amperage) to melt battery terminals. I don't know if an internal short in the battery could cause that, but then again, I wouldn't think the battery charger OR the alternator was capable of putting out that much power either, unless somehow you got 120VAC going into the battery.

Time to disconnect everything, and check each piece very carefully before theboat burns down. An Islander28 is an exceptionally well-mannered boat, it would be a shame to burn one up!


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## nicferrante (Oct 10, 2007)

*we are very concerned...*

yes, we are very concerned and just realized that our steaming light is missing!!! Maybe those wires being exposed are causing it? I am not sure how long its been gone. We have been sailing about every other weekend, but we are on her every weekend just hanging out. We still are new to sailing and this boat so we are working thru all the kinks. I think we are going to call out an electrician and hope for the best! Thanks again for all the advice.


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## nicferrante (Oct 10, 2007)

*re: to possible AC getting to the batteries*

The last few times we left the boat in the slip we did not plug her in...we have had such problems with the batteries that we were trying to isolate it and see if there was an AC issue or battery charger issue. Before we arrived to the slip we had motored for 3.5 hours from Ventura to Santa Barbara because we had no wind, so the batteries should have been fully charged. We even docked at the accommodation dock and turned her off and then restarted her with no problem. Our bilge is hard wired to the batteries so we do not need to be plugged in for that to kick in.


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## sailingdog (Mar 19, 2006)

The fact that the batteries are depleted indicates a short of some sort. Most battery cables should have a fuse between the battery and the main DC panel...but not all do. Obviously a fuse isn't involved, since it hasn't blown and unless the fuse is huge, any load that would melt the battery terminals should blow the fuse. 

The amperage doesn't have to be that high if there is a high-resistance element involved, which is why I am leaning towards the battery cables being corroded. That would require less current to generate the same amount of heat.


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## Stillraining (Jan 11, 2008)

Got to go with the dog in this one...We have a pretty large fleet of trucks and heavy equipment...I have personaly burned off a few battery posts...It's *ALWAYS *a connection at the battery..

When your charging what I do an hour and a whole crew will shut down you dont shut down to fix stuff like that you drive a nail between the post and the battery cable and keep going. Then fix it after hours..sometimes you forget and it stays that way for a while and works loose again then you hit the starter one time and up in smoke the post goes.

*Never ever *had a post burn off from over amped charging systems or shorts or any of that stuff in 30 years around heavy equipment and trucks.and believe me we have had every conceivable thing Short out ,burn up ,overamp you name it...Again its *always* a loose/bad connection at the battrie to take the post out.

Not trying to sound like a know it all... but I know this one..

You have more then one problum...you definitely have a draw somewhere to drain the batteries but thats not what fried your post...Clean both post and cable on the new one tell they shine..use a tool like below and actually take some oxidized lead off..get them good and tight and then grease them up..you wount loose another one..IF you do I'll buy it for you.


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## sailaway21 (Sep 4, 2006)

In my experience, you've got one of two things and possibly both. You may have a loose connection somewhere that is causing abnormally high resistence in the wiring resulting in heat at the terminal, in essence the same effect as a short. Or you've got one or more bad cells in your battery(s). I've seen this even in fused systems, where the fuse did not blow (for reasons unknown), and it is a deadly serious issue. The next step is fire and if your batteries are located anywhere near where I think they are, it's going to be catastrophic. Were it my boat I'd be down there right now, not tomorrow, disconnecting those batteries. There could be a benign explanation for this but I wouldn't take the chance that what is an easily remedied situation couldn't well burn your boat to the waterline.

I'm leaning towards a bad battery(s). I've seen a vehicle with this; it died, they got it going, and they pulled in with the engine compartment on fire. Act soon.


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## sailingdog (Mar 19, 2006)

Sway's advice to disconnect the batteries ASAP is a good. Given how much heat is required to melt the battery terminal.... *you need to disconnect the batteries and then trace the problem... IN THAT ORDER. *


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## sailaway21 (Sep 4, 2006)

If I had to take a guess, I'd say Rainy is correct. But please don't wait to disconnect and, given your other "issues", I'd follow btrayfors advise and get an Electro down to go through the boat. It'll take less time than you'd think and the peace of mind......priceless.


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## Stillraining (Jan 11, 2008)

OH Gosh No 

Please Please do not think I was trivializing your problum...Just asserting how the post got fried...I did state you had two problums...find the second one for sure


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## TSOJOURNER (Dec 16, 1999)

Let's get back to basics, Nic. For the battery posts to get hot enough to melt, you have to have a huge current moving someplace. 

You mention your boat has 'the original' battery charger installed. You don't mention how old your boat is, but Islanders have been around a long time. I would seriously suspect your battery charger as the culprit in this case. Old battery chargers had two states. Off and All ahead full! From a technical standpoint they were a 10:1 step down transformer feeding a full-wave bridge rectifier with (maybe) a capacitor to filter some of the ripple down. They had no voltage regulation and no current regulation, so when you turned them on, they went. 

Batteries can only be charged until they're full. If you continue to overcharge them, they get unhappy. When electrical devices get unhappy, the first thing they do is get hot. My guess is that your 'antique' battery charger is overcharging your batteries, and that's why your posts melted. 

I know battery chargers are expensive, but they've become very sophisticated, and are smart enough to know when to cut their charge rate back because the batteries are full. They're worth every penny, because they'll treat your batteries properly. 

Good luck,


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## nicferrante (Oct 10, 2007)

Hey guys- we tried to check the wires/cable and they are all burnt so we cannot really figure out anything ourselves from them. We called someone to come out and I am planning to disconnect the batteries as soon as I get to the boat (assuming the boat is still there) - I'm at work.


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## Stillraining (Jan 11, 2008)

Hope your insurance is paid up..


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## sailingdog (Mar 19, 2006)

good enough. Keep us posted.


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## nicferrante (Oct 10, 2007)

okay-- so we had a marine electrician come out and he determined that the main battery positive unfused cable came in contact with the air cleaner of the engine. The cables became so hot they melted the insulation around them, melted the lead of the battery terminals exposing the liquid electrolite inside the battery.
Most likely there will be some damage to the battery charger and then once that is up and running we need to check the engine.

Thanks to all for your assistance and advice, we appreciate it.


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## hellosailor (Apr 11, 2006)

Hmmm...air cleaner usually is comparatively COLD on an engine, because of all the cold air being sucked in through it. In any case it sounds like you got lucky, not to have a battery explosion and engine fire.

One hopes the new cables will be properly secured to bulkheads, routed away from hot areas, jacketed if they do pass near them, and fused directly on the battery. A battery explosion could really ruin your day.


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## RXBOT (Sep 7, 2007)

*short*

I think it's more likely the cable rubbing on the air cleaner because of vibration when running wore a hole in the insulation and said cble had a dead short and heated up etc.


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## sailaway21 (Sep 4, 2006)

Nic,
I feel much better-you should too!


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## nicferrante (Oct 10, 2007)

You guys are all correct, We were told that we are very lucky to have not had an explosion. The electrician was staring and speechless for about 5 minutes. He took lots of pictures because he said he has never seen anything like this. I am happy that this did not happen when we were on the water and that we made it into a slip.


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## sailingdog (Mar 19, 2006)

When you replace the cables, route them in a safer path and put them in a cable chafe protector.


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## Stillraining (Jan 11, 2008)

nicferrante said:


> okay-- so we had a marine electrician come out and he determined that the main battery positive unfused cable came in contact with the air cleaner of the engine. The cables became so hot they melted the insulation around them, melted the lead of the battery terminals exposing the liquid electrolite inside the battery.
> Most likely there will be some damage to the battery charger and then once that is up and running we need to check the engine.
> 
> Thanks to all for your assistance and advice, we appreciate it.


Well Im not ready to eat crow yet...We have burnt several cables right in half at the starters and never melted a post that way...I still bet there was a combination of a loose or bad connection at the post in order for it to start arcing and melt like that. Guess anything can happen, we'll never know now though...


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## bselly (Feb 11, 2009)

*A second case...*

I have just had nearly this exact same situation happen to me this morning. The engine would not start so we sailed in and I shut off the entire system and left for work, none the wiser, but my girlfriend found the melted post and a hole into the battery continuously spitting acid...she says the cables are in good condition???... I'll take pictures....

PS. also on a 29 year old yanmar diesel


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## HoffaLives (Feb 19, 2007)

It doesn't take a short to melt posts as it's more about resistance than anything. High current will cause melting, but the worst will be at points of highest resistance. Even an alternator putting out 70 amps can melt a corroded junction. Resistance equals voltage drop, and that loss of power is what creates the heat.

Fuses generally will not stop melted connections/terminals/fires, as they are designed to fail in an overcurrent situation, not a high resistance connection situation. 

While the house battery will (should be) fused, the cable to the starter will not be, due to the excessively high current demands. so this is a risky area, requiring that both the terminals at the starter and battery ends be properly and rigorously maintained. if not, you will likely burn out cables or terminals before you notice problems with a starter.
resistance is the enemy and the cause of most boat fires.


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## Giulietta (Nov 14, 2006)

Hey!!

Hoffa...you're alive???

What's new??

sailing much??


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## hellosailor (Apr 11, 2006)

"and a hole into the battery continuously spitting acid"
Sounds like an internal short, which in turn is boiling the electrolyte at the short itself, and that's why the battery is "spitting" acid.
The good news is that if you haven't had a fire or explosion YET, you probably won't as the battery is burning itself out. Mind the acid, and if you have any warranty take it back. Otherwise, off to disposal.


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## HoffaLives (Feb 19, 2007)

Giulietta said:


> Hey!!
> 
> Hoffa...you're alive???
> 
> ...


wow, you're still alive? i thought you would have disappeared into one of the CIA's black sites by now.

Just coming up for air. Spent the last year writing and illustrating 130 training units for the prov. government's new marine technician apprenticeship program. We sail as often as we can, a couple of times a month at least. Just had a long weekend through the gulf Islands. Life is damned sweet. You?


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## Giulietta (Nov 14, 2006)

HoffaLives said:


> wow, you're still alive? i thought you would have disappeared into one of the CIA's black sites by now.
> 
> Just coming up for air. Spent the last year writing and illustrating 130 training units for the prov. government's new marine technician apprenticeship program. We sail as often as we can, a couple of times a month at least. Just had a long weekend through the gulf Islands. Life is damned sweet. You?


Same old same old..

CIA?? what's that?? Cyalis Induced Anally??   

Hey..sailing, work..sailing, work...nothing new..my kid's in the nationals now in the main team..ohh forgot!! also created a new sailing forum, called Anything-Sailing....and moved there...not much time to be here lately

Check it out...you'll like it.

Alex


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