Battery Explosion

I've got twin Cummins 555's in my "new" GB 49.
My mechanic has been working on changing fluids, filters, etc. since we just bought the boat.

He went into the engine compartment yesterday to find the starboard 8D battery bubbling battery acid after it had exploded. No other damage, and fortunately no fire.

He cleaned things up well.

Any ideas on cause? The battery was probably over ten years old.

Capt. Sea Fever

Hydrogen gas build up

If one cell shorts, the remaining cells overcharge and boil dry. Then at the tail end when bone dry, there is an arc and it ignites the hydrogen. Boom.

Check your batts. If one cell is way different with regards to electrolyte level, it is about to do the above.

A neighbor of mine had a battery explode - I heard it from inside my boat. It was a sealed lead acid battery. He said the acid went everywhere. They used a special indicator spray to find areas of acid spill/spray. It took quite a bit of work to find and clean up every spot. You might want to check for yourself to be sure there's no more remaining.

Richard

+1. Battery stores sell a yellow foaming spray that turns red when acid is present. I'm not sure but the foam may have a neutralizing component as well.

If you mix up a concentrated baking soda solution, you can spray it in the area and watch for bubbling where the acid remains. In the process, it will neutralize the acid. Use liberally on detected spots.

Aft Deck Capt said:

+1. Battery stores sell a yellow foaming spray that turns red when acid is present. I'm not sure but the foam may have a neutralizing component as well.

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FlyWright said:

If you mix up a concentrated baking soda solution, you can spray it in the area and watch for bubbling where the acid remains. In the process, it will neutralize the acid. Use liberally on detected spots.

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Yes - I think that's pretty much the regimen that my neighbor followed.

I have the idea, rightly or wrongly, that explosion is more an issue of sealed than unsealed batts. For a start, sealed,so more risk of a good explosion if it happens. Plus, no method of adding water as it disappears, which I know is not supposed to happen, but they do have that wretched eye thing which is supposed to tell you the liquid is disappearing, even though it "doesn`t", because the batt is sealed, which it almost is, but not quite.
I `d rather have unsealed LA batts, even if they need top up, or because they can be topped up, and because I think they are less likely to explode. If they were inaccessible, AGMs.

BruceK said:

I have the idea, rightly or wrongly, that explosion is more an issue of sealed than unsealed batts. For a start, sealed,so more risk of a good explosion if it happens. Plus, no method of adding water as it disappears, which I know is not supposed to happen, but they do have that wretched eye thing which is supposed to tell you the liquid is disappearing, even though it "doesn`t", because the batt is sealed, which it almost is, but not quite.
I `d rather have unsealed LA batts, even if they need top up, or because they can be topped up, and because I think they are less likely to explode. If they were inaccessible, AGMs.

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Yes indeed - my neighbor replaced his SLA with an AGM.

I had a 4D fail in my sailboat. It boiled over and I had battery acid 2 inches thick in the battery well. It was a pain to clean up but I used lots of baking soda to neutralize it. Fortunately, no explosion.

BruceK said:

I `d rather have unsealed LA batts, even if they need top up, or because they can be topped up, and because I think they are less likely to explode. If they were inaccessible, AGMs.

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I agree. My house bank and my thruster/windlass bank are both the original, Chinese, sealed LA 8D batteries. The boat is 7 years old, the batteries could be 8 years old. I don't expect they will last a lot longer, maybe a couple of years if I am fortunate. Sealed LA batteries in a boat always make be a bit nervous. When I replace them it will either be with AGM, or more likely LA GC batteries with a watering system.

10 year old LA batts? If I bought a boat with 10 year old batteries, they would be the first thing to go. I am no battery expert but I have never had a LA battery last even 7 years.

"Any ideas on cause? The battery was probably over ten years old."

You have answered your own question.

If you are thinking of replacing your batteries you probably have waited too long already.
I just replaced my thruster battery. The performance was like I upsized the thruster motor. Wow. You don't notice the slow failure. But you do notice the improved performance of a new battery.

dhays said:

I agree. My house bank and my thruster/windlass bank are both the original, Chinese, sealed LA 8D batteries. The boat is 7 years old, the batteries could be 8 years old. I don't expect they will last a lot longer, maybe a couple of years if I am fortunate. Sealed LA batteries in a boat always make be a bit nervous. When I replace them it will either be with AGM, or more likely LA GC batteries with a watering system.

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You practice dentistry. You advise your patients to get regular checkups. Suggest you replace your batteries now rather than having the boat doctor tell you why your vessel needed a root canal.

The battery industry considers a unit scrap when its AH capacity has dropped, to 80% of original.

If you monitor that metric, you can set your own threshold.

Otherwise use the calendar.

Worst option is just wait, until it fails "unexpectedly". The mode of failure may be catastrophic esp on a boat.

In my opinion a properly designed and managed electrical system will never surprise you.

All good points. So far, the batteries have been performing really well. However, they have lived a relatively pampered life. The engine start and genset start batteries have both been replaced. The genset start battery was replaced a year ago with a group 31 AGM. The engine start battery was replaced by the PO.

I think part of the reason the house and thruster batteries have performed for so long is that they have been pampered. Unlike the main and genset start batteries, they live in the aft lazaret instead of the hot ER. All charge sources are directed at the house bank, and then a Duo-charger is used to charge the thruster bank. There is a SOC meter that automatically cut out the house bank at 50% SOC. When I got the boat I changed that to 70%.

Even so, I can't imagine them lasting too much longer which is why I am starting to think about what I want to do next.

And I learned something new today! Geez! I have no idea how old my batteries are.

Power boats and yachts have a tendency to ignore our batteries. We stay plugged in with a charger running so it appears that our batteries are fine. Engines start (because the charger is running). When not plugged in either our gen set or our mains are running (or both). So the batteries are rarely made to perform.

So in our idyllic world everything is ok. Mains started - battery is good. Stereo working - battery is good. Drinks cold - battery is good. Then something happens and nothing works because the battery is NOT good.

Sailboat(er)s as a general rule take better notice of their batteries because they use them more to their design capacity than most power boats. Learn from the sailors and take better care of your batteries and they will last longer and really work when you need them.

wwestman said:

Power boats and yachts have a tendency to ignore our batteries. We stay plugged in with a charger running so it appears that our batteries are fine. Engines start (because the charger is running). When not plugged in either our gen set or our mains are running (or both). So the batteries are rarely made to perform.

So in our idyllic world everything is ok. Mains started - battery is good. Stereo working - battery is good. Drinks cold - battery is good. Then something happens and nothing works because the battery is NOT good.

Sailboat(er)s as a general rule take better notice of their batteries because they use them more to their design capacity than most power boats. Learn from the sailors and take better care of your batteries and they will last longer and really work when you need them.

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Thanks for the advice wwestman and everyone!
I've replaced both batteries and have learned a lot from everyone's replies!!

When you replace your batteries do yourself a favor and hire the local handyman or yard service guys to pack them in and out of the boat. Your back will thank you.

1-Count your blessings that no one was in the ER at the time!
2-The battery terminals were covered with a GB covered battery box right? Uncovered positive terminals are an unnecessary potential accident lying in wait. Hydrogen gas is a product of LA battery charging. In the concentration range of 5%-20% with air (almost always present somewhere on top of a battery) it detonates like a bomb from the slightest spark. Even a loose terminal nut could cause that spark.
FWIW, the explosions of the Fukushima nuclear plants were the result of hydrogen gas detonations on a grand scale.

Capt. Sea Fever said:

Thanks for the advice wwestman and everyone!
I've replaced both batteries and have learned a lot from everyone's replies!!

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For the life of me I do not understand folks who push the envelope on battery replacement. On an annualized basis the cost to replace is minimal while the cost of a potential catastrophe is not.

catalinajack said:

For the life of me I do not understand folks who push the envelope on battery replacement. On an annualized basis the cost to replace is minimal while the cost of a potential catastrophe is not.

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Penny saved and all that. I understand what you are saying about annualized cost. Even so, if you have $1000 invested in a bank of batteries, by getting 6 years vs 5 years out of them, you save a couple hundred bucks. Get 7 years instead of 5 then you save even more.

Maybe in the scheme of things that isn't a lot, but laying out another boat buck at any time is always painful for me.

dhays said:

Penny saved and all that. I understand what you are saying about annualized cost. Even so, if you have $1000 invested in a bank of batteries, by getting 6 years vs 5 years out of them, you save a couple hundred bucks. Get 7 years instead of 5 then you save even more.

Maybe in the scheme of things that isn't a lot, but laying out another boat buck at any time is always painful for me.

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Agreed but seven years vs. Five years does not (depending on care, of course) seem to me to be pushing the envelope. But some guys seek to extract every last day of use. To that is what I was alluding. Then there is the situation where we have a new boat owner who is only guessing about the age of the batteries and knows nothing about the PO's care but does know that the batteries are not at all new. Should be replaced don't you think? That was precisely my situation. Eight replaced at about $900. Good to go now for the next 5 to 7 years. Sleeping well.

catalinajack said:

Then there is the situation where we have a new boat owner who is only guessing about the age of the batteries and knows nothing about the PO's care but does know that the batteries are not at all new. Should be replaced don't you think? That was precisely my situation.

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I resemble that remark.

I know that both my house and thruster banks are original, so that is at least 6 years of use, and likely they are at least 6 months older than that. At least I know how they were charged even if I don't know how deeply and how often the house bank was depleted.

I am in the process of thinking about what I want to do with the batteries. I am confident that I can get another season out of them while I consider options. My genset start battery died as soon as I took possession of the boat last year. I replaced it with a group 31 AGM. If it that had happened now, I would simply connect it to my engine start battery and eliminate the separate genset start battery. At the time, I didn't have any experience with this boat, never mind no experience with powerboats in general.

At this point, the contenders for a new house bank are wet cell GC batteries, AGM GC batteries, or just replace the 3 8D sealed LA with 3 x 8D AGM.

Sounds like a SOC meter would be a wise install.

dhays said:

My genset start battery died as soon as I took possession of the boat last year. I replaced it with a group 31 AGM. If it that had happened now, I would simply connect it to my engine start battery and eliminate the separate genset start battery. At the time, I didn't have any experience with this boat, never mind no experience with powerboats in general.

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When it came time, we eventually replaced the original genset start battery -- a G27 FLA -- with a 68-Ah G34 AGM... but we left it attached to the original 40-amp 3-bank charger which also services two 300-Ah dual-purpose banks.

That worked OK, but bank charging wasn't balanced all that well... and the charger is undersized for that total capacity... so I eventually disconnected the genset start battery from the charger. Now we're relying on the generator alternator for that. The AGM doesn't self-discharge very much. No ill effects so far, and it also means we still have a third layer of redundancy should we draw down one of the large banks too far.

IOW, I think your replacement has merit, may well contribute nicely to an overall belt-and-suspenders approach...

The rest... of the story... in our case is that last year we installed a separate inverter/charger and segregated our two large banks.... so now the 40-amp charger services only one of the 300-Ah banks. A larger charger for that bank still wouldn't hurt, either, but I don't have to do that until the original craps out.

-Chris

dhays said:

At this point, the contenders for a new house bank are wet cell GC batteries, AGM GC batteries, or just replace the 3 8D sealed LA with 3 x 8D AGM.

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I've been pleased with our Odyssey G31 AGMs. Especially since that means I've been able to divert my own labor hours to other stuff...

It happens our available space and shape limits one of our main dual-purpose banks to either one 8D, three G31s, or four GC2s. Rough estimates, that'd be approx 245, 300 (our current configuration), or 440 Ah. This is the bank that now has it's own inverter/charger, so I'm just in the process of replacing the 11-seasons-old G31s with Lifeline 6V GPL-4CT AGMs.

(Got the new batteries reserved, new box and installation bits and pieces on hand... just getting through a couple more weeks of our fishing season before making the change.)

I think three GC2s will usually fit where one 8D fits. If so, maybe you could easily stuff eight GC2s in there, approx 880 Ah vs approx 735 for three 8Ds?

-Chris

FF said:

Sounds like a SOC meter would be a wise install.

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I have one for the house bank. It is helpful and I have it set to cut out the inverter when the house bank is down to 70% SOC. That still gives me plenty of room for my 12v refrigeration, lights, head, and fresh water pump while at anchor.