Battery system and tray questions after survey

[ChasingEden]

Hi, I've just put a deposit down on a Catamaran and had a survey done. The surveyor said he didn't like the look of the electrical system because it looks messy. However, the current owner installed it himself and is a retired electrical engineer. He says he will sign off on it as he knows it is sound. The surveyor didn't do any real testing of the system and only had a brief look at it. He suggested I have an electrician look at the system, which couldn't hurt for a piece of mind. He also mentioned that the batteries should be in a tray in the event of an acid leak. Is this the norm for all boats? And should the tray be something like a stainless steel tray that holds a few batteries each? There are 10 batteries altogether and some are really hard to get too. Cheers in advance

[smac999]

I would have someone look at it. people always think they are smarter then they are. boat systems are complicated and unique. I've fixed things that a university electrical engineering prof did before... and many other people that thought they were smart.

batteries should be in compleatly enclosed boxes. not just a tray. to stop them from moving around, and also to contai battery acid from spilling or from a rare battery explosion.

[RaymondR]

You might be amazed at the change in appearance of an electrical system that half a dozen cable ties can make.

The only reason a metal tray would be an improvement over fibre glass or poly is that a fire is less likely to propagate from a metal enclosure.

[GordMay]

Greetings and welcome aboard the CF, ChasingEden.


Congratulations!
Do you have any photos?

[StuM]

What sort of batteries? My AGMs aren't in boxes, they are just secured by tie downs.

[ChasingEden]

Originally Posted by smac999

I would have someone look at it. people always think they are smarter then they are. boat systems are complicated and unique. I've fixed things that a university electrical engineering prof did before... and many other people that thought they were smart.

batteries should be in compleatly enclosed boxes. not just a tray. to stop them from moving around, and also to contai battery acid from spilling or from a rare battery explosion.

Yeah for peace of mind I will have a marine sparky look at it. I will take his advice into consideration for the battery trays. But I think it is a good idea.

[ChasingEden]

Originally Posted by RaymondR

You might be amazed at the change in the appearance of an electrical system that half a dozen cable ties can make.

The only reason a metal tray would be an improvement over fibreglass or poly is that a fire is less likely to propagate from a metal enclosure.

Yeah absolutely, I can guarantee if I went around and cable tied it all up then it would look half decent.

Ok, so would the acid eat through the boats fiberglass? Also if the batteries are tucked deep in the cupboard, how will I know if the deepest one has exploded? I'm guessing the performance of the system along with actually seeing the leak.

[ChasingEden]

Originally Posted by StuM

What sort of batteries? My AGMs aren't in boxes, they are just secured by tie downs.

Sealed AGM batteries. Ok good to know, thanks

[Dulcesuenos]

Originally Posted by ChasingEden

Yeah absolutely, I can guarantee if I went around and cable tied it all up then it would look half decent.

Ok, so would the acid eat through the boats fiberglass? Also if the batteries are tucked deep in the cupboard, how will I know if the deepest one has exploded? I'm guessing the performance of the system along with actually seeing the leak.

We're on our 4th cat and not 1 had batteries in boxes or trays except the start batteries when in an eng compartment. (Thinking to protect the batt mostly from salt water etc.
Have had 2 batteries exploded over the years, 1 was an 8d that was left on charge for 2 years and forgot was this way when we looked at the boat,,,, acid everywhere, no damage to the fiberglass.

[travellerw]

Originally Posted by ChasingEden

Yeah absolutely, I can guarantee if I went around and cable tied it all up then it would look half decent.

Ok, so would the acid eat through the boats fiberglass? Also if the batteries are tucked deep in the cupboard, how will I know if the deepest one has exploded? I'm guessing the performance of the system along with actually seeing the leak.

No, battery acid will not eat fiberglass. Many boats actually have battery boxes made from fiberglass.

[Sailmon]

Sealed batteries (agm, gel) eliminate the risk of acid leakage. That said, batteries must be strongly secured/strapped/tied down so they don’t become lethal IFOs (identified flying objects) in a knock down, collision, etc. We use a cam latch strap on our house bank (3 group 27 AGMs) and a West Marine battery bracket on our start battery. If not in a sealed box it is also critical to put protectors on the terminals to prevent accidental shorting when the battery compartment is open.

[Jammer]

Originally Posted by ChasingEden

Hi, I've just put a deposit down on a Catamaran and had a survey done. The surveyor said he didn't like the look of the electrical system because it looks messy. However, the current owner installed it himself and is a retired electrical engineer. He says he will sign off on it as he knows it is sound. The surveyor didn't do any real testing of the system and only had a brief look at it. He suggested I have an electrician look at the system, which couldn't hurt for a piece of mind.

That an electrical installation is "messy" may mean a wide variety of different things, ranging in importance from the trivial to the profound.


Boats move. Power cables should be attached to things in such a way that the cables do not bend or flex more than necessary when the boat moves, and so that no force is exerted on the terminals as the result of motion. A side effect of doing this is that the resulting installation usually, but not always, looks "neat." A qualified individual performing an evaluation of the cabling system would comment on whether the cabling is of the proper size, sensibly routed, correctly terminated, and adequately secured -- not on appearance.



I wouldn't believe the seller, or the surveyor, based on what you've said. Whether you want to fiddle around getting an electrician involved (some are better than others here also) and at what point is something you'll have to decide yourself.

He also mentioned that the batteries should be in a tray in the event of an acid leak. Is this the norm for all boats? And should the tray be something like a stainless steel tray that holds a few batteries each? There are 10 batteries altogether and some are really hard to get too.

The whole point behind AGMs is that there isn't any liquid in them to spill or leak.



Some people treat them like flooded batteries for safety purposes anyway on the grounds that there may be some possible failure modes where they vent or leak. I believe that flooded batteries are a better deal overall than AGMs so that's what I use. If I had AGMs I would not use a tray but would be sure they are secured in place.

[Jammer]

Originally Posted by ChasingEden

Yeah absolutely, I can guarantee if I went around and cable tied it all up then it would look half decent.

So, cable ties are better than nothing. And they are fine for holding cables together in a bundle.


For attaching cables to a fixed object, you want to use a neoprene cushioned stainless steel cable clamp along with a screw or rivet or other suitable fastener. They are much stronger than the nylon ties with the screw loop in the end, which will tend to break under heavy repeated stress.

Also if the batteries are tucked deep in the cupboard, how will I know if the deepest one has exploded? I'm guessing the performance of the system along with actually seeing the leak.

Well, batteries don't just explode. They explode from things like overcharging and loss of electrolyte and being charged while frozen. For AGMs you should be monitoring voltage and current and have a means of isolating the parallel strings and monitoring them separately. Things like discharge voltages that are too low, charge currents that are too high, or inability to deliver a reasonable percentage of the rated capacity are all red flags. With AGMs if the charge voltages are too high they will go straight to hell very quickly. Deal with problems as they occur, and save yourself the drama.


If you have batteries tucked "deep in the cupboard," you may want to reevaluate whether the battery installation meets your needs. Perhaps that really is the best way, but you may be better off with a more accessible installation, even if it means somewhat less capacity, or giving up some locker space.

[Time2Go]

Originally Posted by ChasingEden

Hi, I've just put a deposit down on a Catamaran and had a survey done. The surveyor said he didn't like the look of the electrical system because it looks messy. However, the current owner installed it himself and is a retired electrical engineer. He says he will sign off on it as he knows it is sound. The surveyor didn't do any real testing of the system and only had a brief look at it. He suggested I have an electrician look at the system, which couldn't hurt for a piece of mind. He also mentioned that the batteries should be in a tray in the event of an acid leak. Is this the norm for all boats? And should the tray be something like a stainless steel tray that holds a few batteries each? There are 10 batteries altogether and some are really hard to get too. Cheers in advance

Have a look at the Youtube videos
of Jeff Cote of
Pacific Yacht Systems
doing electrical audits
of various boats
A real eye opener
Cheers
Neil

[Cpt Pat]

Originally Posted by StuM

What sort of batteries? My AGMs aren't in boxes, they are just secured by tie downs.

I agree. My AGMs are well secured without "boxes," but at first, my surveyor dinged the configuration. I took one battery out on the dock, turned it upside down, and challenged him to find any leakage. I then pointed out that, in AGMs, the electrolyte is never in a liquid state. You can break it open with a sledgehammer and it won't leak a drop. The same is true of lithium batteries.

Some surveyors are unaware of the new battery technologies.

He also dinged me for having fused direct-connect wires to the battery that bypassed the master breaker/cutoff -- until I explained that those leads ran to my bilge pumps. Some of the ABYC standards defy common sense, and some pertaining to electronics need to be updated.

I've seen some horrendous battery installations where the battery is just bouncing around loose inside a box. It'll chafe the battery case and stress the wiring. And the battery will likely turn into a loose cannonball in a knockdown or roll.

IMHO, flooded batteries have no place on a vessel that heels, and are unseaworthy on a vessel that can potentially roll unless they are mounted in an apparatus that can gimbal through 360 degrees of roll (which I've never seen). And there's no way to prevent a flooded battery from outgassing some acidic electrolyte - which corrodes everything around it, or to prevent the battery from outgassing explosive hydrogen when its charging (AGMs won't do that unless they are severely overcharged). I don't want to even think about the consequences of having any battery that can fling sulfuric acid at my eyes residing inside a box that will leak if its inverted. Flooded batteries are dangerous and unreliable old tech on a sailboat. Their only advantage is that they're (initially) cheap (but only rich people can afford cheap batteries).

I have two Odyssey and two Lifeline batteries. They are now 8 years old, have been through hundreds of partial cycles, and still test above 90% rated capacity. Properly charged AGMs are cheaper than flooded batteries in the long run.