Powder on battery terminal

[hellosailor]

To check for bubbles or spatter:
First, clean and dry the battery. Now lightly dust it with talc, just enough to leave a faint white dust all over the top. Talc is inert, it won't hurt anything.
Charge your battery. Come back and look at the talc. It will be obviously disrupted where any liquid has bubbled up or spattered or trickled through.

If any liquid has come up around the posts, that's a defective case. You can live with it, probably, but if so put felt "battery post" washers on. All the battery/auto shops sell them, a felt donut the size of a silver dollar, impregnated with a mild alkali to neutralize acids. You slip it over the post then put the cable terminal on top of it. (I suppose you could also add a tiny bead of caulk under that, just around the post.)

If you are spattering from the cells, that's charging too quickly. Electrolyte shouldn't be boiling.

"Normal" charging does release acidic vapors. Look at every old Fiat that had a wet acid battery in the trunk (and the old Mazda coupes) and you'll see they all magically have been rusted out from acid vapors. BMW and VW/Audi still use "breathing" tubes to discharge vapors from their sealed AGM batteries. But in normal charging, with clean cables? No excuse for corrosion and crud.

[Olly75]

Well I had an interesting morning relearning physics; added baking soda and then a couple of cap fulls of water and got a nice bubbling green foam. Cleaned it all up and there are no cracks round the terminals. However, I tested the voltage and got 10.3v (the battery has been hot for some time as well....) so I'm assuming its toast, unless anyone thinks otherwise?

I then had a look at my other banks and discovered two other batteries that were very hot, one with a bulging side as well, so disconnected them both, tested, and got 6.3 and 6.5 in each (they are six volters). I'm assuming that the one with the bulge is toast, but is is possible to save the second one that seems to be the right shape?

[Uncle Bob]

Originally Posted by Olly75

Well I had an interesting morning relearning physics; added baking soda and then a couple of cap fulls of water and got a nice bubbling green foam. Cleaned it all up and there are no cracks round the terminals. However, I tested the voltage and got 10.3v (the battery has been hot for some time as well....) so I'm assuming its toast, unless anyone thinks otherwise?

I then had a look at my other banks and discovered two other batteries that were very hot, one with a bulging side as well, so disconnected them both, tested, and got 6.3 and 6.5 in each (they are six volters). I'm assuming that the one with the bulge is toast, but is is possible to save the second one that seems to be the right shape?

Hi,I am not known as a psychic but from your description I can see a new bank of batteries in your future . If you have only one 6 volt battery that you think MAY be ok then it is time to replace all so as you have a matched set in the bank. You don't want to have one battery pulling down the rest which would lead to early replacement of them all.

[hellosailor]

If these are all similar "maintenance free" batteries, you may consider replacing them all. A bulging battery is physically damaged and dangerous to continue charging. Mixing 6 and 12 volt batteries in the same system also makes it possible for someone to make a cable error, if those 6v batteries were installed in parallel instead of as a 12v series pair...they'd be very unhappy, overheating and bulging. Trashed.

Yes, different batteries can be run together, but that is always a kludge, they will never match the performance of "all alike".

It might help to describe the entire system.

[john61ct]

Yes toast, only good for the core charge.

Replace all in the bank together, if a separate one the same age seems fine maybe use it that way a bit longer but watch it.

In general people should get to know their bank so they will see the deterioration long before you get to this point.

A properly selected installed and managed bank should never give surprises.

[Olly75]

Well, the entire system as I understand it (I only inherited it on Friday last week so investigations are still ongoing......) is as follows:

Shore power
4kw Northern Lights genny
Engine

1no 12v battery to crank the genny (now condemned as only holding 10.5v and charging hot)
2 house banks each of which has 4no 6 volt 190ah batteries. Both banks are run in series.
In one of the house banks two batteries in series are charging hot, one of which is now bent out of shape.

I have what appears to be 2 chargers and also one inverter/charger.

Is is possible to have one house bank with four 6v batteries and the other with 2. Asking as Im trying to limit the financial damage of this venture.....

Im also going to go through an efficiency drive to reduce consumption and install solar.

[DockDoc]

Was at work could not reply. Looks like the forum answered all pertinent concerns.

Oh Uncle Bob, yea Pillar seal goes bad you get bubbles that was my thinking at least.

"Physics"?!? Why does physics get all the credit... chemistry people, chemistry... we are core science too..it's not all black holes and Einstein Rosen bridges..

..lurches back to the lab to cry under the fume hood..

[Uncle Bob]

Originally Posted by Olly75

Well, the entire system as I understand it (I only inherited it on Friday last week so investigations are still ongoing......) is as follows:

Shore power
4kw Northern Lights genny
Engine

1no 12v battery to crank the genny (now condemned as only holding 10.5v and charging hot)
2 house banks each of which has 4no 6 volt 190ah batteries. Both banks are run in series.
In one of the house banks two batteries in series are charging hot, one of which is now bent out of shape.

I have what appears to be 2 chargers and also one inverter/charger.

Is is possible to have one house bank with four 6v batteries and the other with 2. Asking as Im trying to limit the financial damage of this venture.....

Im also going to go through an efficiency drive to reduce consumption and install solar.

Olly, any combination for a bank is possible provided that all batteries in the bank are of the same voltage, and preferably of the same capacity and age.
On my boat the house bank consists of six six volt golf cart batteries of 235 a/hrs each wired in series/ parallel and the start bank is 2 12 volt group 31 batteries in parallel. The start bank is for the engine and windlass only, everything else comes from the house bank. So far so good.

[GordMay]

Originally Posted by DockDoc

... "Physics"?!? Why does physics get all the credit... chemistry people, chemistry... we are core science too..it's not all black holes and Einstein Rosen bridges..

..lurches back to the lab to cry under the fume hood..

Reminds me.
Q: Why do chemists call helium, curium and barium the medical elements?
A: Because if you can't helium or curium, you barium!