Re: [Amel Yacht Owners] Battery Compartment Explosion
Danny and Yvonne SIMMS
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Hi James, I agree completely with your analysis of the venting and airflow. Just for everyones info we never get battery gas smell in the inside of the boat, even when undertaking the controlled overcharge during desulphation.
If there is hydrogen gas built up an ignition source such as a spark could set off an explosion. However in a charge situation with lead acid batteries (james I know yours were not) inadequate venting from the individual batteries can cause a battery to explode. At normal charge rates the built in vents are adequate. At boost charging rapidly the battery caps should be removed, the lid on the battery chamber left closed (on the SM) and the gas vents externally. I would not desulphate with a closed battery box as the 54 has.
SM 299 Ocean Pearl
From: "James Wendell ms42phantom54@... [amelyachtowners]"
Sent: Friday, 24 June 2016 10:45 PM
Subject: Re: [Amel Yacht Owners] Battery Compartment Explosion
I hear from Danny that the SM has battery compartment venting at the bottom that allows air to move up through the battery compartment. That is the way to do it, as it allows make-up air to enter and go out the exhaust and therefore vent any hydrogen sulfide if it is released. While wet cells will release small amounts of H2S in operation, normally, AGM batteries do not release gas, as it is recombined internally.. Vents at the bottom would also prevent any gasses from leaking into the boat itself.
The 54 does not have any ingress, only egress through the vent. It is sealed tight. That is what caused the build-up of hydrogen gas. The batteries themselves did not explode - 2 of them cracked a bit at the top, which is what caused the gas to release. The others were damaged as a result of the explosion.
I am sorry to disagree with other opinions, but air circulation is needed. Yes hydrogen sulfide is a toxic agent, but after my experience, it would be far better to let a little bit of it vent into the boat in an emergency situation, versus contain it in an enclosure that is essentially a bomb when the battery vents faster than the passive vent can exhaust it outside.. In reality, it would not vent into the boat if the air intake is lower than the exhaust. H2S is lighter than air and will rise naturally.
Just for clarification, there was no essentially no charging occurring here; while no one has definitively identified the culprit, the accepted conclusion at this point is that one or two of the batteries suffered an internal short and breached on their own - likely because they were nearing the end of life at 4 years, but they came with the boat and I have no record of their service history. There was a slight solar power charge coming in, but it was early in the morning and little sun would have been illuminating the panels. There IS temperature compensation, and the solar charger is a nearly new 45-amp Morningstar MPPT controller. While it certainly could have failed, it was operating fine just before the event.
I will report more if my insurance surveyor or the electrical experts here in the yard are able to offer additional inputs.
Just as a side note, I know Amels are good boats, and I see that. They are well built. However, I have noted some less-than-stellar design decisions that likely are more the result of EU regulations rather than Amel philosophy.
I have owned the boat now for just over a year. I have only sailed/motored it for 4 days last June. Immediately after that initial delivery the engine failed. I am not going to repeat that story, but the final analysis proved that during my 4-day motor from FL to MD, saltwater had migrated into the exhaust manifold and up into the head - not because of cranking. When the water evaporated a week after arrival in MD, salt crystals remained in the engine and pitted the valves and valve seats. That seriously compromised the engine and the only good solution was a new engine. Yes, I could have rebuilt it for about half the cost - not worth it as there was a fair amount of external corrosion on the starboard aft side of the engine. The second design flaw is that there are NO fuses in any of the primary DC feeders from the batteries. That is a serious issue, as any short-to-ground or system overloads would have overheated the circuit and caused the affected wire to melt or catch on fire. Fuses are needed to protect the wires at the battery. I changed all of that and now have an array of fuses in the compartment adjacent to the batteries. And now the sealed battery compartment issue.
Perhaps I am venting now, but as others have noted, I will persevere and resolve all of these issues. I do appreciate the quality that goes into these yachts.
Thanks for the support - that is what this group is all about.
s/v Phantom Amel 54 #044
On Friday, June 24, 2016 3:28 AM, "Jean-Pierre Germain jgermain@... [amelyachtowners]" wrote:
Your AMEL ownership has been marred by unusual problems; mine has also not been a bed of roses but for different reasons.
I had a NICAD battery runaway once. At High altitude, The events take a different dimension.
Persevere, these are good boats and you will be well rewarded eventually
On 24 Jun 2016, at 08:10, Danny and Yvonne SIMMS simms@... [amelyachtowners] <amelyachtowners@...> wrote: