Argh - battery problem.

[alistair1537]

Hi All

 

I want to get advice on the aux. terminal of my battery - it is one of two fitted for my bow thruster. 

 

The story so far - I have been the owner from new of my barge - around 6 months - fitting out. Recently I decided to open the battery box housing the bow thruster batteries. Not opened before, so due for an inspection and clean. I noticed some build up of the dreaded green "moss" around the positive terminal and removed the battery for a proper clean...that's when I noticed the cracked terminal clamp...then the eroded terminal...

 

I think the cracked clamp was arcing and eroded the terminal...the terminal is now leaking, causing the green moss to "escape"...

 

My idea to resolve this is to move the cables over to the available aux. post - the thread size is the same for nuts. Repair the leaking terminal with either silicone or epoxy and leave be.

 

Question: Can the Aux. post take the current draw? Probably around 600A? If yes, then, is there a better sealant for the damaged battery post? 

 

Cheers

 

Alistair

[Alan de Enfield]

41 minutes ago, alistair1537 said:

Can the Aux. post take the current draw?

It is the same size as the post on the clamp terminal so the answer is 'yes'.

[BEngo]

If you still have them put one of the red plastic protective caps over the now redundant terminal.  It will reduce the possibility of unwanted shorting.

 

N

[MtB]

58 minutes ago, alistair1537 said:

Question: Can the Aux. post take the current draw? Probably around 600A?

 

Yes.

 

 

[1st ade]

You may well find that the "post" is a casting with a tapered outside and a threaded inside - screwed onto one of the two threaded terminals on (each polarity of) the battery.

 

But don't twist it too hard trying to find out!

[Tony Brooks]

Not that this helps but I would say that battery was incorrectly manufactured. When I was building batteries there was a lead post that came through the lid from the plates and we put a mould over it. We then used a town gas -oxygen torch, "probing/mixing rod", and lead filler stick to melt the lead post etc to form a solid battery post. On the photo you can see the inner post has only been melted to the outer post at the top. Thsi may just be modern manufacturing though.

 

I think that unless the OP seals that gap he will continually get acid growths. I would suggest at the least he fill the hole with Vaseline or battery terminal dressing and then put a clamps around it.

[Slim]

3 minutes ago, 1st ade said:

You may well find that the "post" is a casting with a tapered outside and a threaded inside - screwed onto one of the two threaded terminals on (each polarity of) the battery.

 

But don't twist it too hard trying to find out!

I don't think so . My Leoch AGMS came with male threaded posts,(only 1 female thread per polarity) and the posts had a very shallow hexagon 'nut' at the base.

[Tony Brooks]

It looks to me as if the taper post is melted onto/into a lead ring that has been cast/moulded into the cell lid, as per those I built so its not screwed on. You can see a lead ring flush with the top of the lid where the mould would have sat and no hint of a gap where the post would have been screwed down onto it.  Its because the completed post (all the bits melted together) is in effect moulded into the lid that means its all too easy to twist the post and crack the lid by lack of care when spannering.

[Jen-in-Wellies]

On the cracked clamp. The first set of clamps I had on the house batteries on my boat suffered very badly from this. Many of them cracked within the first three or four years of the boats life. I replaced them all and none have cracked seven, eight years later. You may have been unlucky with the batch you had. No way of telling if replacements will suffer the same problem or not.

I agree with @Tony Brooks, put some vaseline or battery terminal gunk in the eroded bit of terminal to seal it. Should be OK for the rest of the batteries life. Worth smearing some on all the battery terminals, clamps to prevent corrosion.

Jen

[alistair1537]

Hi All

 

Well, thanks for all the advice - I put some vaseline on all the terminals and glued a protective plastic cap over the entire terminal. I put the whole lot back together and using the Aux. post it seems to be okay. I haven't used the bow thruster in anger yet, so I'll be sure to let you know if it fails or blows a fuse - at some imperative point in the future.

 

Thank you again

 

Alistair