extra sole hatch to access bilge

[Wanderlust]

I want to create a new battery area in my bilge as my 3 batteries, stored under the port lazarette, create a definite list to port. The bilge in the MKII has a deep section (to bottom of keel)with the bilge pump but also a sloped section which drains things forward of the deep section. This forward section starts about half the depth of the deeper section, and runs forward for about 32 inches, This basically "unused" area goes from 28 inches tall to 20 and is about 10 inches wide at the bottom and gets wider as you get closer to the sole, following the hull.
So, I want to add a new hatch in the sole, glass in some supports in the sloped bilge and put my batteries down there. Id leave some room under the added supports to keep drainage open and I wouldnt cut any floor stringers. Itll be a pain for sure but puts the battery weight low and keeps them cool. Any structural reason that I cant cut an extra hatch in the sole?? Any other reason this is crazy??

[Carl Thunberg]

You didn't mention whether you have lead acid batteries, but if you do, this sounds very unsafe. I'm afraid I don't know much about gel batteries, so I don't know the safety issues there. They may be much safer, I just don't know.

The electrolyte is a solution of sulfuric acid and water. During normal operation, water is lost from a non-sealed (or floooded) battery due to evaporation. During charging, lead acid batteries produce hydrogen and oxygen gases as electrolysis occurs. Many lead acid explosions are believed to occur when the electrolyte fluid level falls below the plates in the battery, allowing space for hydrogen/oxygen to accumulate. When the battery is engaged, it can create a spark that ignites the accumulated gases and causes the battery to explode. If something's going to explode on my boat, I would hope it would be above the water line and inside a cockpit locker. I've always assumed this is why I've never seen batteries inside the living space. I wonder what ABYC says about this. At a minimum, it's worth looking into.

[Wanderlust]

My batteries are gel which supposedly have less issues.
I was under the impression (maybe a wrong impression) that batteries were frequently kept in living areas such as under berths, settees and even under soles but I dont know the official recommendation.

And you have a point about lead batteries producing hydrogen. The bilge has less ventilation than my cockpit locker but also less things which make sparks to ingnite it. I would imagine a battery explosion would be awful no matter what and maintainence is important.

[Cathy Monaghan]

Hi Wanderlust,

This spring we moved and upgraded our batteries. The old battery box was high on a shelf in the port cockpit lazarette of our CD32. We had 2 Group 27s in there.

We now have 1 Group 24 lead acid battery in the old spot (Bank 1 starting battery) and 2 6V golfcart type AGM batteries (Bank 2 House) in what was the storage compartment at the forward end of the quarterberth.

We now have additional storage space on the shelf in the lazarette, which makes up for the lost space in the quarterberth locker. Though there is still some space in there for limited storage.

You can install AGM batteries inside the boat but not the lead acid batteries. AGM batteries can also be installed on their sides, something you cannot do with lead acid or Gel batteries. AGM batteries are considered non-gassing and are safe for boats and RVs. They DO NOT spill if knocked over and they are fully submersible.

We also added two large hatches in the cabin sole of our boat. The original hatch, the one in front of the companionway, was small. I could barely clean down there. And when it came time to replace the hose that runs from the head to the holding tank, it was nearly impossible to work down there. So enlarging the original hatch and adding a second hatch has made a BIG difference in the ability to get at stuff, e.g., hoses and wiring, that's beneath the cabin sole. It has also created a fantastic storage area for us.

Here are some photos of the two large hatches in our boat's cabin sole. The smaller one forward provides access to the knotmeter's transducer. We were refinishing the cabin sole when these photos were snapped, so that's the reason for the blue tape.

<a href="http://i30.photobucket.com/albums/c349/ ... .jpg"><img width="600" src="http://i30.photobucket.com/albums/c349/ ... 8.jpg"></a>

<a href="http://i30.photobucket.com/albums/c349/ ... .jpg"><img width="600" src="http://i30.photobucket.com/albums/c349/ ... 2.jpg"></a>

<a href="http://i30.photobucket.com/albums/c349/ ... .jpg"><img width="600" src="http://i30.photobucket.com/albums/c349/ ... 5.jpg"></a>

<a href="http://i30.photobucket.com/albums/c349/ ... .jpg"><img width="600" src="http://i30.photobucket.com/albums/c349/ ... 7.jpg"></a>

Here's a photo of the two 6V batteries in the quarterberth locker. The photo was snapped before the lids for the battery boxes were secured in place. They are also held in place with webbing straps. NExt year we plan to reroute those hoses.

<a href="http://i30.photobucket.com/albums/c349/ ... .jpg"><img width="600" src="http://i30.photobucket.com/albums/c349/ ... 0.jpg"></a>

Anyway, there's no reason you can modify the space beneath the cabin sole for your battery banks.

Hope this helps,
Cathy
CD32 Realization, #3
Rahway, NJ
Raritan Bay

[Boyd]

I too have looked at that bilge space in my MKII with envy and thought seriously about moving batteries there.

The existing hatches are placed between athwart ships stringers and I don't see how adding another one would compromise anything structurally as long as you respect the existing stringers. Cut a stringer and you will have problems.

What has stopped me are two challenges.

The first is how to support and access batteries on the sloped and confined space that exists.

Several years ago I contacted Lifeline about the possibility of standing a 4D AGM vertically in the space and they were totally ok with the idea. Seems AGM's can be mounted any way but upside down. Since then, through an expensive experience, I have come to appreciate the advantages and value of golf cart batteries as a house bank over AGM's or Gel's which returns to the problem of how to support, load, maintain, and just plain access 4 wet cell batteries in that location.

The second is, should your bilge flood and seawater gets to the batteries you could have a bad short at best, a fire at worst. If seawater gets into a wet cell battery it destroys it immediately. Losing battery power to run the bilge pump when the bilge is flooding could be a really unfortunate circumstance. AGM's or Gel's would not have the seawater intrusion problem but would still short out. Seawater is an excellent conductor.

I an currently considering the space under port bunk in front of the fuel tank as a good option for battery relocation. I am thinking about lining them up against the inside bulkhead where the vertical height is greatest. I temporarily moved the batteries there to approximate the effect on list and it helped considerably. The only problem is the A/C lives there. One problem usually begats another.

One contributor to this board, Larry DeMers I believe, located his under the V berth.

Let us all know how you go about it if you do mount them in the bilge. Its just too tempting a spot.

Boyd
s/v Tern
CD 30 MkII
Fort Lauderdale, Fl

[Wanderlust]

Wow Cathy, thanks for the reply. It appears that your 32 has almost exactly the same layout as my MKII 30. Your new hatches are exactly what I had in mind. I like your idea of using it for general storage instead of batteries but my bilge always seems to have an inch of water which the pump cant remove and so it is somewhat damp down there. And putting the batteries low seems like a nice benefit.
And Boyd, I was going to glass some stringers to the sides of the hulls and add a flat platform, maybe even a stepped platform depending on space and need. But now youve scared me with that idea of shorting out in a flood. Ill be considering the suggestion about locating them forward of the fuel tank. And Ill look at the V-berth but its a long way from my panel. Its always something.

[Cathy Monaghan]

.....What has stopped me are two challenges.

The first is how to support and access batteries on the sloped and confined space that exists.....

You can do this if you create a new floor hatch and build a new floor for the batteries to sit on. We had to do that in the quarterberth locker on our boat so that we could store our batteries in there. You can just see the floor in the photo that I included in my post above. It is supported by by 1" x 3/4" stock that's been both glued and screwed to the side walls. The floor was then screwed down with hefty fasteners. (I know that thru-bolting would have been better, but there was just no way to do it.) The battery boxes are held in place with webbing straps and their lids are held down the same way. We cut the top panel of the berth so it is now two pieces, so you don't have to remove the entire thing to get at the batteries. An additional support was sistered to the bulkhead that separates the new battery compartment from the water tank compartment aft. Then the lid, or top panel of the berth, is screwed down on top of everything.

In the bilge area you'd have to glass two stringers in place -- one on each side of the bilge walls, just long enough for the battery box(es). Install them as far aft in the sloping area of the upper bilge as possible so that you don't impede access to the deep bilge and so that you'll still have a storage area forward of the battery boxes. Orient them so that the batteries will sit level or nearly level on the new floor. Set the floor (3/4" plywood - painted) on top of the two stringers and thru-bolt it in place. With new floor hatch(es), you should have easy access down there. Anyway, it can be done.


Cathy
CD32 Realization, #3
Rahway, NJ
Raritan Bay

[Cathy Monaghan]

....I like your idea of using it for general storage instead of batteries but my bilge always seems to have an inch of water which the pump cant remove and so it is somewhat damp down there. And putting the batteries low seems like a nice benefit.....

You should note from the photos that nearly all of the items stored in the bilge are stored in the sloping area forward of the deep bilge. Everything is stored in crates or plastic tubs so nothing gets wet. That big round white bucket is a beer-making bucket, 6-gallons I think. It is the only container stored in the deep bilge and it doesn't touch the bottom of the bilge so it's not sitting in water. We fill it with canned and bottled beer and other beverages. All of our bottled water is stored in the upper bilge area as well. You can see some it in the photo. It's in a crate that is pushed up against the mast compression post, and more in the blue crate.

Storing the heavy stuff, like bottles and cans, down under the floor also helps to keep weight low in the boat and it doesn't really matter if they get wet, but they don't -- not on our boat anyway.

There's alot of storage space beneath the cabin sole. Whatever you decide to use it for, that project will be well worth it.


Cathy
CD32 Realization, #3
Rahway, NJ
Raritan Bay

[sfreihofer]

I would be concerned about putting batteries in the bilge because of the propensity for flooding which could cause shorts, and the accumulation of explosive gases in a poorly ventilated and confined area during the charge/discharge cycle.

Even more worrisome is that with lead acid batteries, not only is the battery ruined by the intrusion of salt water, but seawater reacts with sulfuric acid to produce chlorine gas, which is extremely toxic and deadly.

Stan
Ft. Lauderdale

[Carl Thunberg]

I checked ABYC E-11 and there's no guidance there. I also spoke with a good friend of mine who owns a trawler. His battery bank is under his bunk where he sleeps every night, so I guess I need to withdraw my concern. I learned something today . If you do this, just make sure you have a good smart charger, which I'm sure you already have. Anyway, here's the link to ABYC E-11 if you want to take a look.

http://www.boatdesign.net/boat-design-w ... lGuide.pdf

[Boyd]

Cathy, your storage system has inspired me to redo my bilge arrangement. There is just too much good space down there to it let continue to go unused. I really like your hatch solution, they make access much better than what came standard. I too never realized how similar the 32 and the MkII are in interior layout.

Taking this one step further, it would be possible to create a battery space that is sealed on 5 sides and off the bottom of the bilge so that flooding would not let water get to the batteries till it reached the floor level. Having the batteries under the bunk would give you another 8 inches of flooding space above the floor before the batteries went. That 8 inches could be really important if you had a serious hull breach. Located as CD installed them in the cockpit locker you would have to virtually sink the boat before they flooded.

I think having the batteries under the bunk and the canned goods in the bilge is a better situation that the reverse and a good compromise solution to solve my chronic list.

Boyd
s/v Tern
CD30 MkII
Fort Lauderdale, Fl.

[Larry DeMers]

Carl,

There can be no "spark" inside a battery when it is being used. Where would that come from? Battery explosions (very rare) usually are associated with cars, and commonly, the car was getting a jump from another car when the jumper cable causes a spark near the battery, and ignites a pocket of hydrogen (which in itself is highly dispersive..it readily passes through that balance of gas and oxygen content that can cause an explosion).

Putting the battery bank down in the bilge could be a problem if the boat should ever develop a leak. Seawater and battery acid produces a horrible poisonous gas..phosgene?? memory is not sure there. But it should be avoided due to this.
If a water proof container could be fit in the bilge (it can't..I tried) then I might think about this idea more seriously.

As an alternate idea, may I suggest the solution that I came up with.

Since the CD30 is somewhat heavy by the stern anyway, I placed two banks of two Trojan T105 golfcart batteries up under the vberth. One set is directly behind the holding tank in a wood case that I built, and is held in place perfectly by the fiberglass moldings in that location (like it was made for this). The second bank of batteries is in a 'Blue Seas' battery box, under the vberth filler piece. I then placed a wood shelf over the battery box, and have room for two large tool boxes. All of this weight up forward balances the boat nicely, keeps the weight low and just forward of the center of gravity. I have used this placement for 5 years now, and would not change it.

My opinion, and I'm sticking to it!! heh...


Larry DeMers
s/v DeLaMer
Cape Dory 30 Sailing Lake Superior

You didn't mention whether you have lead acid batteries, but if you do, this sounds very unsafe. I'm afraid I don't know much about gel batteries, so I don't know the safety issues there. They may be much safer, I just don't know.

The electrolyte is a solution of sulfuric acid and water. During normal operation, water is lost from a non-sealed (or floooded) battery due to evaporation. During charging, lead acid batteries produce hydrogen and oxygen gases as electrolysis occurs. Many lead acid explosions are believed to occur when the electrolyte fluid level falls below the plates in the battery, allowing space for hydrogen/oxygen to accumulate. When the battery is engaged, it can create a spark that ignites the accumulated gases and causes the battery to explode. If something's going to explode on my boat, I would hope it would be above the water line and inside a cockpit locker. I've always assumed this is why I've never seen batteries inside the living space. I wonder what ABYC says about this. At a minimum, it's worth looking into.

[tmsc]

Carl,

Do you have access to a link for ABYC E-10. That is the standard that covers batteries.

I don't have a link and it probably would not be right to post the whole standard here its too long, but I think this is the info that he is looking for:

E-10.7.9
A vent system or other means shall be provided to permit the discharge from the boat of hydrogen gas released by the battery.
E-10.7.10
Battery boxes, whose cover forms a pocket over the battery, shall be vented at the uppermost portion of the cover.

NOTE TO 10.7.9 and 10.7.10: These requirements also apply to installations of all batteries whether they employ removable vent caps, non-removable caps, are “sealed” or “maintenance free” batteries, or have pressure regulated valve vent systems with immobilized electrolyte (gel batteries).