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#1
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Cautionary tale
While picking people's brains about batteries today, I learned why I
haven't seen a friend of mine around the waterfront in a while. He isn't in Florida. He was bending over the battery in his boat a couple months ago when it blew up for no apparent cause. In addition to acid burns, the force of the explosion threw him against the bulkhead of his boat so hard that he broke ribs and punctured his lungs. He's been laid up for weeks. I don't think wet cells have any place on a boat except maybe one that is large enough to have a dedicated battery compartment. -- Roger Long |
#2
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On Tue, 15 Mar 2005 20:51:49 GMT, "Roger Long" wrote:
While picking people's brains about batteries today, I learned why I haven't seen a friend of mine around the waterfront in a while. He isn't in Florida. He was bending over the battery in his boat a couple months ago when it blew up for no apparent cause. In addition to acid burns, the force of the explosion threw him against the bulkhead of his boat so hard that he broke ribs and punctured his lungs. He's been laid up for weeks. I don't think wet cells have any place on a boat except maybe one that is large enough to have a dedicated battery compartment. Any further details? I'm just finishing the battery box on my boat, and maybe there's something I need to know. Hope your friend recovers soon. Norm B |
#3
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"Roger Long" wrote in message .. . While picking people's brains about batteries today, I learned why I haven't seen a friend of mine around the waterfront in a while. He isn't in Florida. He was bending over the battery in his boat a couple months ago when it blew up for no apparent cause. In addition to acid burns, the force of the explosion threw him against the bulkhead of his boat so hard that he broke ribs and punctured his lungs. He's been laid up for weeks. I don't think wet cells have any place on a boat except maybe one that is large enough to have a dedicated battery compartment. I agree totally. Liquid lead-acid batterys have a bunch of problems. They are obsolete technology for boat use. Gel or AGM are far better choices. Even with a dedicated battery compartment Liquid Lead-Acid batteries are still dangerous. Doug s/v Callista -- Roger Long |
#4
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After a day of researching batteries, I think the only thing you need
to know is to put AGM batteries in your boat. They will work charging off standard alternator / voltage regulator combinations, unlike gel batteries. More expensive but I think you have to have a really good reason to carry a gallon or more of liquid sulfuric acid around in your boat. According to Calder, wet cells have longer life and better performance but only with a degree of care and feeding that isn't probable on most boats. The real life mileage of gel's and AGM's is greater because they are more tolerant of the abusive cycles inherent in most marine applications. I just went to give my spare aircraft battery its periodic maintenance charge. I just moved it to the edge of the shelf in the small room where I keep it and the phone rang. I realized a half hour later that my eyes burned and my fingers itched. Just the fumes of a battery sitting there are corrosive. It boiled over slightly the last time I charged it and I didn't notice. Two months later, the residue could make me feel that way. Think of that stuff in your boat. The only way I could justify wet cells now would be a long distance cruiser that needs technology available anywhere, can spend a lot of time maintaining them, and needs maximum performance. If you must go wet, vent the battery box so the air flow is completely separate from the interior of the boat. -- Roger Long "engsol" wrote in message ... On Tue, 15 Mar 2005 20:51:49 GMT, "Roger Long" wrote: While picking people's brains about batteries today, I learned why I haven't seen a friend of mine around the waterfront in a while. He isn't in Florida. He was bending over the battery in his boat a couple months ago when it blew up for no apparent cause. In addition to acid burns, the force of the explosion threw him against the bulkhead of his boat so hard that he broke ribs and punctured his lungs. He's been laid up for weeks. I don't think wet cells have any place on a boat except maybe one that is large enough to have a dedicated battery compartment. Any further details? I'm just finishing the battery box on my boat, and maybe there's something I need to know. Hope your friend recovers soon. Norm B |
#5
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"Roger Long" wrote in
: I don't think wet cells have any place on a boat except maybe one that is large enough to have a dedicated battery compartment. - Er, ah, what kind of batteries do you have that AREN'T "wetcells"? Gelcells are wetcells....So are AGMs....In the first the acid is jelly. In the second, the acid is simply absorbed by a gauze-like glass mat in between the rolled up lead plates. They're still all lead-acid batteries and will STILL ALL EXPLODE! Wait until you see a big AGM battery that has an internal short and turns all that mat into steam!....BOOM! There's nothing holding the plates apart in an AGM battery.....for all that money.... |
#6
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"Doug Dotson" dougdotson@NOSPAMcablespeedNOSPAMcom wrote in
: I agree totally. Liquid lead-acid batterys have a bunch of problems. They are obsolete technology for boat use. Gel or AGM are far better choices. Even with a dedicated battery compartment Liquid Lead-Acid batteries are still dangerous. Doug s/v Callista Drop by a battery shop with the big golf cart batteries. Turn one of 'em upside down and see what leaks out with the caps on. I dare ya...(c; The best batteries for a boat are those big, honkin' fork lift batteries, but most have no place to store that much energy or boat enough to float that much weight..... POWER is our friend. What worries me in a glass mat battery is COOLING. The wetcell battery is cooled by convective currents in the electrolyte. The flow through the plate separators vertically keeps a constant flow of cooling water preventing the plates from warping. How do you cool an AGM battery all wrapped up in INSULATING FIBERGLASS when that big, honkin' 180A alternator is trying to satisfy a boater who wants to charge the hell out of it for an hour to shut down his little diesel, instead of letting it charge SLOWLY so it can absorb the energy in its relatively slow chemical reaction to charging current?? Nope...I like liquid-cooled, hard motion (golf cart or fork lift) batteries...thanks. EVERY big truck comes with them...Ships, too! I wonder why?? I suspect his friend had either a primary wiring short with no fuse link to melt, like most boats are wired to the panel, or an internal cell short out, which is very rare in a modern battery...very rare. Question - Is he a smoker or could have had something hot near the charging cells? There's very little gassing, now that we got rid of the antimony plate supports, unless he was charging the hell out of it fully charged. |
#7
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What was he doing? Checking the water level with a cigarette lighter?
In my experience I have had only one battery explode and it was an AGM my son had in his car. He had a big alternator to power his obscenely large stereo amp. When the regulator failed the battery started overcharging and blew up. Nobody hurt but it cost about $2,200 to replace the hood, grill, radiator, fender liner and all the hoses. I will stick to L-16s and recombinant caps thank you. -- Glenn Ashmore I'm building a 45' cutter in strip/composite. Watch my progress (or lack there of) at: http://www.rutuonline.com Shameless Commercial Division: http://www.spade-anchor-us.com "Roger Long" wrote in message .. . While picking people's brains about batteries today, I learned why I haven't seen a friend of mine around the waterfront in a while. He isn't in Florida. He was bending over the battery in his boat a couple months ago when it blew up for no apparent cause. In addition to acid burns, the force of the explosion threw him against the bulkhead of his boat so hard that he broke ribs and punctured his lungs. He's been laid up for weeks. I don't think wet cells have any place on a boat except maybe one that is large enough to have a dedicated battery compartment. -- Roger Long |
#8
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#9
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Glenn Ashmore wrote:
What was he doing? Checking the water level with a cigarette lighter? In my experience I have had only one battery explode and it was an AGM my son had in his car. He had a big alternator to power his obscenely large stereo amp. When the regulator failed the battery started overcharging and blew up. Nobody hurt but it cost about $2,200 to replace the hood, grill, radiator, fender liner and all the hoses. I will stick to L-16s and recombinant caps thank you. And I'll stick to Golf cart batteries. At least I can lift them! Evan Gatehouse |
#10
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You make an excellent point that no battery is safe. Anytime you store
up that much power in a small package there is going to be risk when things go wrong. AGM's certainly can explode if abused. However, explosions are only part of it. The free liquid acid, corrosive fumes, and explosive vapors of wet cells are all minimized with AGM's. If something does go wrong and one blows up, the acid impregnated mat in the AGM should be less dangerous and easier to clean up than the liquid. This is analogous to the gas / diesel propulsion question. If you need the very best performance and power to weight ration, you have to go with gas and learn to keep large amounts of explosive fume producing liquid on board. With care, understanding, and proper equipment, gas can be made acceptably safe. Diesel is not perfectly safe but it is much safer and has other advantages such as more moisture tolerant ignition. Despite the blanket statement I started this thread with, there are certainly operational situations in which I might choose wet cells. I wouldn't expect them in normal yachting situations though. Speaking of internal shorts, the AGM, with everything held in place with the glass mat should be far less likely to short than the wet cell where chunks can fall off the plates and there is only liquid to keep them from moving around. -- Roger Long |
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