12v positive battery terminal corrosion

Skylark

Skylark

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My domestic bank is 4 x 110 Amp-hr SLA, 4 years old, same age as the boat. It has a Beneteau fitted multi stage charger. I imagine that we put the bank through a fairly typical marina bertholder duty cycle; 6-month season, some weekends sailing, some caravaning and a couple of weeks summer cruise. The positive connection post on one battery has blue (anhydrous copper sulphate?) corrosion deposit. Boat and battery boxes are dry, terminals are tight. All other connections, positives and negatives, are clean. I've cleaned off the deposit, lightly greased everything and remade the connection. Everything seems fine. Should I be worried?
 
davidjackson said:
My domestic bank is 4 x 110 Amp-hr SLA, 4 years old, same age as the boat. It has a Beneteau fitted multi stage charger. I imagine that we put the bank through a fairly typical marina bertholder duty cycle; 6-month season, some weekends sailing, some caravaning and a couple of weeks summer cruise. The positive connection post on one battery has blue (anhydrous copper sulphate?) corrosion deposit. Boat and battery boxes are dry, terminals are tight. All other connections, positives and negatives, are clean. I've cleaned off the deposit, lightly greased everything and remade the connection. Everything seems fine. Should I be worried?
Click to expand...


I wouldn't be worried.
 
davidjackson said:
My domestic bank is 4 x 110 Amp-hr SLA, 4 years old, same age as the boat. It has a Beneteau fitted multi stage charger. I imagine that we put the bank through a fairly typical marina bertholder duty cycle; 6-month season, some weekends sailing, some caravaning and a couple of weeks summer cruise. The positive connection post on one battery has blue (anhydrous copper sulphate?) corrosion deposit. Boat and battery boxes are dry, terminals are tight. All other connections, positives and negatives, are clean. I've cleaned off the deposit, lightly greased everything and remade the connection. Everything seems fine. Should I be worried?
Click to expand...
I believe that fumes migrate up through where the posts pass through the plastic cases and then react with the brass clamps. As I have posted recently, my Numax batteries lasted 9 years until the other week. Does yours have flush caps with penny slots in? If so, do as I did on a regular basis and top them up.
Home this week but back in Gib end of month.
Stu
 
davidjackson said:
My domestic bank is 4 x 110 Amp-hr SLA, 4 years old, same age as the boat. It has a Beneteau fitted multi stage charger. I imagine that we put the bank through a fairly typical marina bertholder duty cycle; 6-month season, some weekends sailing, some caravaning and a couple of weeks summer cruise. The positive connection post on one battery has blue (anhydrous copper sulphate?) corrosion deposit. Boat and battery boxes are dry, terminals are tight. All other connections, positives and negatives, are clean. I've cleaned off the deposit, lightly greased everything and remade the connection. Everything seems fine. Should I be worried?
Click to expand...

Copper sulfate but but not anhydrous as that is not blue.
 
davidjackson said:
The positive connection post on one battery has blue (anhydrous copper sulphate?) corrosion deposit. Boat and battery boxes are dry, terminals are tight. All other connections, positives and negatives, are clean. I've cleaned off the deposit, lightly greased everything and remade the connection. Everything seems fine. Should I be worried?
Click to expand...

Cannot explain it scientifically, but I think, no you shouldn't worry. When I bought my lovely B361 10 years ago, the positive connection on engine battery was similar (don't remember if it was blue, but it was something like salt around the terminal). I cleaned it, lightly greased it (still do this from time to time), remade the connection and it still looks fine. I guess the connection was not very good.

PS: Forgot to mention, I hope you had a nice with many sea miles summer this year!!!
 
Thanks to all for reassuring responses. The boat has 7 batteries but just one (of a bank of 4) shows this corrosion. Strange.......I'll check the terminals more frequently in future.

Hi Stu,

These are the terminals

iPhone%20to%20Aug%202017%20194.JPG


As you're home, you should have come to the HH Old Gaffers/Traditional Boat Festival. It was not as well supported as it has been in previous years but still good. Uncharacteristically, the weather played ball, too. There's always a berth available..........

Hi Philippos,

Thanks for posting, good to hear from you. The weather here this season has been quite mixed but I've managed a few miles under the keel. Now that I've retired (early, I hasten to add!) I can get to the boat during the week and enjoy some peace and quiet (did I really write that :))
 
davidjackson said:
Thanks to all for reassuring responses. The boat has 7 batteries but just one (of a bank of 4) shows this corrosion. Strange.......I'll check the terminals more frequently in future.

Hi Stu,

These are the terminals

iPhone%20to%20Aug%202017%20194.JPG


As you're home, you should have come to the HH Old Gaffers/Traditional Boat Festival. It was not as well supported as it has been in previous years but still good. Uncharacteristically, the weather played ball, too. There's always a berth available..........

Hi Philippos,

Thanks for posting, good to hear from you. The weather here this season has been quite mixed but I've managed a few miles under the keel. Now that I've retired (early, I hasten to add!) I can get to the boat during the week and enjoy some peace and quiet (did I really write that :))
Click to expand...
Bluddy hell! Wish Id known, would have loved to have come up.
Stu
 
PaulRainbow said:
Why on Earth are you using the clamps, rather than bolting straight to the studs ?
Click to expand...

Bought the boat brand new and domestic bank failed on first day. Seems that the Dealer let the batteries go flat during commissioning. The replacements were fitted under warranty but terminals were not like for like. The battery stud is M8 but the wire terminals are 10mm (or thereabouts). Hence the resulting adaptor.
 
davidjackson said:
Bought the boat brand new and domestic bank failed on first day. Seems that the Dealer let the batteries go flat during commissioning. The replacements were fitted under warranty but terminals were not like for like. The battery stud is M8 but the wire terminals are 10mm (or thereabouts). Hence the resulting adaptor.
Click to expand...

Gotcha. I think i'd still prefer to bolt them to the stud with a decent washer though.
 
I agree that the terminal at 8mm will make a reliable connection with a good washer to the 10mm cable end. Simplifying the arrangement also means there are less bits of terminal for a wandering spanner to fall on or a stray wire to wrap round.
 
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