battery charging/fumes issues

[vas]

hello,

over the last three weeks I noticed that on pluging in shore power, my intelligent battery charger (century something rather) will do it's thing as always but after 15-20 mins I could smell this awful battery fumes/boiling etc smell, you know what I mean...

Since I'm quite busy doing "serious" rebuilt work and since the aftdeck is full of timber/tools/benches etc it's not easy to get down to the e/r and see what's up.

So I've being doing the charge 15mins when it smells, turn off charging (manually dropping the fuse on the el/panel) and next day do the same.
Worked nicely for a couple of weeks, only the last few days it's been stinking more and earlier so I cannot properly charge the batteries. Anyway, turned off the fridge so batteries should last for a looong time.

Checking the voltometer on the el/panel I can see that the service batteries are doing fine (showing 28V dropping to 25V after a few days with no charging and the fridge running) BUT the start batteries only register 17V!
On connecting the charger, both banks show as charging at 28V which they should as it's the charger being measured by the el/panel voltometer Stopping the charger, starter battery bank shows a rapidly declining rating starting at 20V and in a few mins down to 17V or so.

For the record I have 2 starting batteries and 4 service batteries. There's also one small (car size thing) battery for the genny.

Now, is it safe to assume that one of my starting batteries is caput and has a few shorted cells?

I do remember that these big heavy things have both poles on one side and looks like they have a full cover bar the 50mm on the side of the two poles. Is it easy to remove that coverl and check, or are they sealed and I'll make a mess?
Planning to remove some stuff off the aft deck and free the port to visit the e/r and check tonight.

Also due to a failing plywood shelf where they stand, one battery is now slanted at around 20degrees along its length. Is that acceptable or should I find a way of leveling it off asap to save it?

few qs appreciate some comments

cheers

V.

 

[Divemaster1]

..........Checking the voltometer on the el/panel I can see that the service batteries are doing fine (showing 28V dropping to 25V after a few days with no charging and the fridge running) BUT the start batteries only register 17V!
On connecting the charger, both banks show as charging at 28V which they should as it's the charger being measured by the el/panel voltometer Stopping the charger, starter battery bank shows a rapidly declining rating starting at 20V and in a few mins down to 17V or so.

For the record I have 2 starting batteries and 4 service batteries. There's also one small (car size thing) battery for the genny.

Now, is it safe to assume that one of my starting batteries is caput and has a few shorted cells?

I do remember that these big heavy things have both poles on one side and looks like they have a full cover bar the 50mm on the side of the two poles. Is it easy to remove that coverl and check, or are they sealed and I'll make a mess?
Planning to remove some stuff off the aft deck and free the port to visit the e/r and check tonight.

Also due to a failing plywood shelf where they stand, one battery is now slanted at around 20degrees along its length. Is that acceptable or should I find a way of leveling it off asap to save it?

few qs appreciate some comments

cheers

V.

In my experience I would say that at least one of your batteries are beyond salvage.... The metal will have collapsed and cell integrity broken... so would not think about charging it any more... sounds like you have gas forming and this is quite explosive, so keep charger off the failed battery !!

In respect to angle, if it's gone, its gone ... if OK 20 degrees may be OK, but not if there is low water (acid) level, or leaking acid, which will not be good for your hull.... so would try to righten....

 

[vas]

In my experience I would say that at least one of your batteries are beyond salvage.... The metal will have collapsed and cell integrity broken... so would not think about charging it any more... sounds like you have gas forming and this is quite explosive, so keep charger off the failed battery !!

In respect to angle, if it's gone, its gone ... if OK 20 degrees may be OK, but not if there is low water (acid) level, or leaking acid, which will not be good for your hull.... so would try to righten....

OK, my thought as well.

Of course I'm planning to remove all batteries (but will need help as they're heavy and in a dodgy position where you have to be folded in half before lifting them) and rebuilt this tray. It's only that I've planned that for winter not now, so would like to have my fridge working and tbh don't care about the starting batteries

Will try to disconnect them from the charger and make sure the four service ones work fine and sort the others out during the winter..

cheers

V.

 

[PaulGooch]

OK, my thought as well.

Of course I'm planning to remove all batteries (but will need help as they're heavy and in a dodgy position where you have to be folded in half before lifting them) and rebuilt this tray. It's only that I've planned that for winter not now, so would like to have my fridge working and tbh don't care about the starting batteries

Will try to disconnect them from the charger and make sure the four service ones work fine and sort the others out during the winter..

cheers

V.

Take the negative cables off of the starter batteries.

Take care, battery fumes are explosive, seriously. Enough to turn a battery into a small bomb. I had one explode several years ago when disconnecting a battery charger (forgot to turn the charger off) and bits off battery and acid went everywhere.

 

[vas]

Take the negative cables off of the starter batteries.

Take care, battery fumes are explosive, seriously. Enough to turn a battery into a small bomb. I had one explode several years ago when disconnecting a battery charger (forgot to turn the charger off) and bits off battery and acid went everywhere.

Thanks Paul,

I'm aware of that, my cousin had his car battery explode on him in front of me, he's lucky to save his eyes! Binned an expensive jacket though

Never let it fume for more than 5mins and now charger is off anyway. So things should be cool when I get down there in the evening. Will wear my safety googles just in case

Biggest thing is removing them from downthere when I rebuilt the full tray...

cheers

V.

 

[PaulGooch]

Thanks Paul,

I'm aware of that, my cousin had his car battery explode on him in front of me, he's lucky to save his eyes! Binned an expensive jacket though

Never let it fume for more than 5mins and now charger is off anyway. So things should be cool when I get down there in the evening. Will wear my safety googles just in case

Biggest thing is removing them from downthere when I rebuilt the full tray...

cheers

V.

Ah, you know what i mean then. Mine also exploded in my face, must have closed my eyes in time, as my face got covered but my eyes were missed. Luckily, there was water nearby.

 

[rafiki_]

Yes V, if the smell is a bit like bad eggs, then 1 or more of your batts is at the end of its life.

 

[vas]

OK, sorted!

Genny battery (a simple 55Ah car battery) was dry and probably is to be scrapped (will give it some juice and see what happens at some point). Should have taken care of this thing when I bought MiToS as genny was having problems turning and firing up...

It was currently permanantly connected to the starting batteries bank (via a dodgy cabling system that I scrapped today) As soon as I removed the genny battery from the system all's fine.

FWIW, all 6 batteries are gel ones (I guess as they have a small round window between the plus and minus poles and no way of opening them to check for juice ) and they seem fine.

After 3h charging I get:

Service: 27.5V
Start: 29V
under charge

and without the charger connected I get:
Service: 26V
Start: 26V

I guess the values are OK, wonder why the start bank charges at 29V maybe it needs more charging?

Question:
What does the panel do with the genny battery. I'm pretty sure we've been through that before, I guess if it does self charge, I'll keep it disconnected from the lot, if not I'll have to have a method of charging it. But from the service bank or engine start bank? I'd have thought the service bank tbh...

More important I'm worried of how I can start the engines quickly if one of the start bank batteries dies... Yes I know I can get down and start rewiring things but it wont be fun and will be rather dark whilst I do it. Any clever thoughts?
I see that the thumb thick cables that go to the engine starter solenoid and engine block respectively are coming straight from these two batteries so not an easy turn the switch and start from the other lot I can think of unless it's a big bugger with massive Amp rating ...

cheers

V.

 

[Divemaster1]

............
More important I'm worried of how I can start the engines quickly if one of the start bank batteries dies... Yes I know I can get down and start rewiring things but it wont be fun and will be rather dark whilst I do it. Any clever thoughts?
I see that the thumb thick cables that go to the engine starter solenoid and engine block respectively are coming straight from these two batteries so not an easy turn the switch and start from the other lot I can think of unless it's a big bugger with massive Amp rating ...

cheers

V.

I have a spring loaded switch on my panel statin "Paralello" ... that activates a solenoid that connects the engines to all 24V systems ... big "clunk" in a engine room switchbox when activated and I have domestic batteries on line for engine startup...

 

[vas]

revived the thread to ask something, hopefully simple!

After a few days charging the batteries I noticed today that

the two starting batteries charge at 31V
the four service batteries charge at 28V

when shore power is disconnected, I get 26V on either set.
Is that normal?
Fridge was running at the time of the test, but I cannot believe that it's to blame. Nothing else was going on.

Ideas?

Cheers

V.

 

[rafiki_]

Sorry Vas, I only have 12v experience, and expect to see 12.7 ish Volts normally, off charge, on charge just under 14v. So with 24v batts, afaik, they have double the number of active cells, so 25.4 ish off charge, and 28 ish on charge.

 

[david_bagshaw]

Have you checked the acid/water level in them recently, as although it sounds if you have battery failure, I have seen batts where there is insufficient liquid in them behave in the same was as you are experiencing now. particularly if you have been on shore power & float charging for a long while, some of the electroylite might have been "lost"

 

[vas]

@rafiki: my thoughts exactly, 28 on charge, but not 30+

@david_bagshaw: sorry should mention the 6 batteries are gel ones, so no way I can check and add juice (at least as far as I understand)

Mind I did mention one is slanted, so that may be a cause of concern, but again that's on the service bank not the starter bank.

oh well...

V.

 

[rafiki_]

@rafiki: my thoughts exactly, 28 on charge, but not 30+

@david_bagshaw: sorry should mention the 6 batteries are gel ones, so no way I can check and add juice (at least as far as I understand)

Mind I did mention one is slanted, so that may be a cause of concern, but again that's on the service bank not the starter bank.

oh well...

V.

Yes 30+ sounds a problem. Could be that you have a short between a couple of cells?

 

[david_bagshaw]

dont know much about gel bats but lead acid

off load recently off charge about 26 good health

off load 24 poor health / flat

on charge 28.5 to 29.5

above 30 overcharging

seems to work for us.

check with a quality digital meter, dont forget many of the affordable meters go out of calibration and over read as its internal battery goes flat.


30 while not on charge sounds as if the zero point of the meter is not correctly set

 

[Jim@sea]

A few years ago I had a starting problem on a Truck and I charged the battery, and it gave off fumes. I called out an Auto-electrician. I told him that the Battery was fully charged. He obviously did not believe me. He put a Heavy Discharge Battery Tester to the battery lugs, and the battery exploded, the top of the battery ceased to exist.
And this Battery was slung underneath the truck, not enclosed in a locker with no venting.
Just shows how careful you have to be with batteries.