Overfilled lead acid battery

[ShipsWoofy]

On a recent inspection we found that both battery banks were low on fluid. Due to the location of said batteries I got my crew to refill each cell. Took quite a lot of water too.

I am now worried that I may have given her duff info and we have overfilled the cells, maybe up to an inch too much water in each cell. Borne out by the fact the batteries just don't seem to have the same capacity as before.

What are my options, I can't just syphon off water as it is now mixed with acid and it will remove valuable acid yes?

Should I just wait for the levels to fall, Aerogen 4 does appear to aid this process?

Should I consider returning batteries to manufacturer (local) for recon, though they were £70 each or so, a couple of hours labour and I might as well buy new?

Add more acid?

Thoughts anyone?

 

[Ships_Cat]

Not sure what you mean by overfilled Woofy one but if just to the bottom of the fill wells then you haven't much to worry about (while normally one fills to about 5mm below the fill wells I always fill to the bottom of the well as it is easy to see the level there from the meniscus that forms). If your crew (can I guess who?) filled above the bottom of the fill wells then I think two situations exist.

If the cells have been filled above the bottom of the fill wells but not been filled so as to cover the gas ventilation slots in the fill wells so as some slot remains uncovered, then I think that you just have to be careful in the first charge to ensure that the expansion and any gassing does not bubble out the vents and not charge hard until enough charge cycles go by to lower the level again. Probably pay to carefully watch the expansion if it is likely to result in the slots being covered.

If the gas ventilation slots in the fill wells are covered then when you charge you will get electrolyte coming out the vents. I assume that you haven't filled so high else you would likely to have experienced this already. If you have, then you are in doggy poo and I suggest that you go kiwi hunting if that is where the fault lies /forums/images/graemlins/smile.gif. I can only suggest that if you are confident handling the acid and have the gear to do so, then talk to the local battery people about what you need to take some off and rebuild with replacement acid to get the concentration up. If me, I would take them to the battery people to do that for me (I'm naturally chicken) maybe having to decant some off before transporting them to prevent spillage.

If I decanted a little off for this purpose, I would dispose of it in the sea (away from the boat a metre or so). And while some will say that will cause the world to be asphyxiated and all the fish for miles around to die, I frankly would not be too concerned myself about there being any danger unless you have an awful lot more batteries than I imagine a poor cat can carry.

John

 

[ccscott49]

If they are not to the top of the filler holes, I would just leave them alone, when you charge the batteries, they may vent some electrolyte, just collect this and dump it, over the side, will not harm the environment. If they are the single filler plugs, you may find you have some electrolyte spilled on the top of the batteries, mop this up, with a rag, wearing rubber gloves!!!!! and dispose of the rag. Just be careful, if you are frightened by any of this, get them to a battery place, or use your hydrometer (you do have one??) and suck a bit of the electrolyte out and put in a jar, dispose later over the side. The amount you will be removing will not effect the battery. As it is, I've never noticed an drop in capacity of my batteries, even when I did overfill them??

 

[webcraft]

ShipsWoofy,

Are you sure your Aerogen isn't overcharging your batteries? This would explain the disappearing electrolyte levels and poor perfomance.

Ours was, and we had to replace both batteries. The regulator had gone. You can tell by listening to or feeling the dump resistor (big green thing) when the batteries are fully charged and the Aerogen is going. The resistor will get warm and it will hum.

- Nick

 

[ShipsWoofy]

Interesting, maybe it is a little paranoia then. I had told her to fill to the bottom of gas chambers, until the water was just a little below, but when I thought about this later, this was higher than what was in the batteries when I bought them.

From the sounds of it a little too much water / electrolyte should not make too much difference, I thought if it was too dilute the capacity would be affected. The amount difference I am talking, from what has been said probably would not be noticed.

I will check the aerogen over, though until the day we filled I was very satisfied with battery capacity, it seems since then we have been having a few power problems. Though, we have not experienced such strong winds either so I might be seeing a weekends use without any top up from the genny while on board.

I will get a hydrometer and have a look, but from what has been said I now don't think that is the problem. I hope it is not a busted regulator!

 

[Ships_Cat]

If by the bottom of the "gas chambers" you mean the bottom of the fill wells (the tubes that extend down from the fill hole with slots in their sides), then you have nothing to worry about at all. That is where I always fill to but do so after a full charge.

I have never noticed any difference in capacity related to the fill level. Not saying there is not, but never been such that I have noticed.

Regards

John

 

[TrueBlue]

Lead Acid batteries do NOT like being overcharged, and I suspect that the Aerogen is doing this for an extended period of time - Sooo get it checked pronto.

Overcharging shortens the battery life and capacity - and that latter point is what you have commented upon...