Moving Lead Acid Batteries to inside the cabin

[smokey73]

I'd like to move my 2 Golf Cart 6V Lead Acid batteries (that are only 2 years old) from high in the boat to some place lower inside the cabin. Not ready for a LFP conversion since these batteries are still very good. Moving the batteries a couple advantages, chiefly a shorter run from the batteries to the electrical distribution panel, less weight up high, and move my batteries from the same compartment as my CNG

Has anyone done this and what considerations should be taken into account. (like outgassing, etc. For Hunter Legend 40.5 owners, where would be a good spot? The height of the GC batteries might be a problem and I'll be searching around for a good spot. I think my battery case is 14 inches tall. At some point I'll be doing a LFP conversion but not at this moment.

All thoughts and cautions, considerations, etc are appreciated.

 

[jssailem]

The general thoughts about battery location are low and central, as close as feasible to the charging and distribution panel.

The complications are based on your individual boat design.

 

[Don S/V ILLusion]

Consider just moving the CNG tank to the other side. Even if you put the batteries inside, the height difference between the aft locker floor and that in the salon isn’t much.

 

[smokey73]

The general thoughts about battery location are low and central, as close as feasible to the charging and distribution panel.

That's my intent. Just have to find a place.

 

[smokey73]

Consider just moving the CNG tank to the other side. Even if you put the batteries inside, the height difference between the aft locker floor and that in the salon isn’t much.

Can't move the CNG tank. The other side has my generator.

 

[smokey73]

Any thoughts on outgassing and the precautions. I know it can lead to corrosion of sensitive electronics so won't put it anywhere near them. Does it have any impact on carbon monoxide and/or smoke detectors? Is active or passive ventilation necessary and any other safety precautions that people use?

 

[dLj]

Any thoughts on outgassing and the precautions. I know it can lead to corrosion of sensitive electronics so won't put it anywhere near them. Does it have any impact on carbon monoxide and/or smoke detectors? Is active or passive ventilation necessary and any other safety precautions that people use?

Back when I used FLA batteries, each would be enclosed in a battery box with cover. I usually had to cut a slot to run the cables between batteries when hooked in parallel but that was simple. Doing it that way I never had a problem with corrosion of anything outside that box.

dj

 

[Don S/V ILLusion]

Any thoughts on outgassing and the precautions. I know it can lead to corrosion of sensitive electronics so won't put it anywhere near them. Does it have any impact on carbon monoxide and/or smoke detectors? Is active or passive ventilation necessary and any other safety precautions that people use?

An uncommon problem. Catalina, among other manufacturers, made thousands of boats in which batteries and the charger/inverter were co-located. None had active ventilation systems. The effect of out gassing corrosion only occurs when batteries are over-charged or malfunctions such as a dead cell occurs, both easily monitored by any voltage management system.

PLus, carbon monoxide detectors can be sensitive to hydrogen gas out gassing but that is a good thing as they inherently warn of battery problems.

 

[smokey73]

I read the Marine How To (Thanks Rod) on Installation and Orientation of Flooded Batteries in Boats. It was very insightful and I have oriented my 1 6V FLA Batteries athwartship as he recommends in his article. He has several pictures of installations inside cabins, some of which are AGM and others but there is one where it is obviously a FLA that is not AGM or GEL. There does not appear to be any active ventilation on the FLA or any of the other batteries installtions and he does not mention ventilation.

Does anyone have a copy of the ABYC

 

[smokey73]

I found a copy of ABYC E-10 which deals with installation of batteries. The following sections state:

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.

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 and AGM batteries).

Section 10.7.10 is pretty easy to understand and implement and most battery boxes have this vent or it can be easily made
Section 10.7.9 is clear a mud What would be considered an adequate "vent system or other means." It says "discharge from the boat" which would not mean just from the battery box or battery container but from the boat interior to the atmosphere
I assume (you know what they say about assume) this means a passive vent to the outside of the cabin is at least required. (Dorad, cowl vent, hatch vent, etc) An active vent would work but doesn't seem viable.

If you have a battery inside your cabin (any kind) how do you meet this requirement and if you have had a survey recently how did they address this?

 

[jssailem]

My FLA batteries were located beneath the salon deck above the bilge. I have placed them in plastic boxes containing acid spills. There is no special venting. Hydrogen is a lighter-than-air gas. It needs to be concentrated to be dangerous. It vents into the cabin and out the companionway. I have a CO2 monitor in the salon and have had a sniffer in the bilge. No alarms have been experienced. Do monitor the battery water levels. Use Personal Protective gear (glasses and gloves) when working with the batteries.

I am careful not to have an open flame in the cabin while charging the batteries.

 

[Stu Jackson]

If you have a battery inside your cabin (any kind) how do you meet this requirement and if you have had a survey recently how did they address this?

I have my batteries inside my cabin.
I haven't met this requirement and don't think that any Catalina owners*** ever have either. No surveyor ever mentioned it.

*** I am the Secretary of the C34IA, and have been since 1999. I am also familiar with most of other Catalina models, having owned a C22 & C25, friends with C36ers and other models, all of which have batteries inside the cabins. The only suggestion made over the years was to put a passive vent into the battery compartment. Don Illusion is right, this is a answer looking for a problem that doesn't exist. I have had FLAs all the time I've owned my boat, a 1986 model I bought in 1998.

 

[smokey73]

If I can find an appropriate space to install the House Batteries I'll go ahead and move them there. If, when I go to sell the boat, the surveyor cites a lack of meeting ABYC requirements regarding ventilation, I'll deal with that when it happens.

 

[Tally Ho]

The batteries on my O’Day 322 are located in the main salon, under a settee. Near center and low.

The height of the golf cart batteries was a bit of a challenge, but I got them in there.

Greg

 

[Rick D]

FYI, there is a 40.5 owner in Switzerland who put them in the keel hollow. The would be great from a weight standpoint, but would require some work. I also do not know what configuration the batteries were.

 

[dLj]

FYI, there is a 40.5 owner in Switzerland who put them in the keel hollow. The would be great from a weight standpoint, but would require some work. I also do not know what configuration the batteries were.

You also have the problem of water - the lower you put your batteries, the sooner they might get covered in water in the case of a leak....

dj

 

[dlochner]

The concern for battery venting is build up of hydrogen. So long as there is a good air path out of the battery compartment to the atmosphere, you'll be fine. Hydrogen is much lighter than air and will dissipate quite quickly given half a chance.

I suspect most of the cabins on our boats are not air tight and leaky enough that hydrogen buildup will not be a major issue. The space between the hull and the interior pan will allow venting to the cabin and then out ports and other vents.

 

[smokey73]

I think putting the house bank in the bilge hollow would be possible but somewhat difficult. In fact, the starter battery is located on a fiberglass platform in the keel hollow (bilge) at the top of the third (aft most) portion of the very large and deep bilge that is formed by the keel hollow.. @Rick D do you have any info on how to contact the guy or where you saw the info? @dLj the keel hollow, which forms the bilge is about 4 feet deep by 1.5 feet wide by probably 8 or more feet long. It is a very big bilge holding about 360 to 400 gallons. Putting it there doesn't occupy otherwise valuable storage space. If I get that much water in the boat and my bilge pump won't keep up with it I'm probably in big trouble anyway.

I've identified two other possible locations.
One is under the Port Settee. Problem is that directly under the proposed battery location is a sole piece that has to slide out to access the large center bilge
Right on the centerline so that is good but will make accessing that portion of the bilge difficult.

The other is under the galley sink. The sole there is fixed and I can attach secure anchor points for the 2 batteries. I will have to move the white drain line for the sink but that will not be too difficult. Just off center to the port. Only about 6 to 8 foot one way to the panel. Current battery to panel is over 20 feet one way.

Any thoughts?

 

[dLj]

I think putting in the bilge hollow would be possible but somewhat difficult. In fact, the starter battery is located on a fiberglass platform in the keel hollow (bilge) at the top of the third (aft most) portion of the very large and deep bilge that is formed by the keel hollow.. @Rick D do you have any info on how to contact the guy or where you saw the info? @dLj the keel hollow, which forms the bilge is about 4 feet deep by 1.5 feet wide by probably 8 or more feet long. It is a very big bilge holding about 360 to 400 gallons. Putting it there doesn't occupy otherwise valuable storage space. If I get that much water in the boat and my bilge pump won't keep up with it I'm probably in big trouble anyway.

I've identified two other possible locations.
One is under the Port Settee. Problem is that directly under the proposed battery location is a sole piece that has to slide out to access the large center bilge
Right on the centerline so that is good but will make accessing that portion of the bilge difficult.

The other is under the galley sink. The sole there is fixed and I can attach secure anchor points for the 2 batteries. I will have to move the white drain line for the sink but that will not be too difficult. Just off center to the port. Only about 6 to 8 foot one way to the panel. Current battery to panel is over 20 feet one way.

Any thoughts?

I'd highly recommend reading the top three reports from 2024 here:

Safety Reports - US Sailing

US Sailing has conducted several independent reviews of sailing accidents, including the 2012 Crewed Farallones Race and the 2012 Newport to Ensenada Yacht Race. Most of these reviews come at the request of the U.S. Coast Guard. These reviews conducted by panelists assembled from US Sailing’s...

www.ussailing.org

dj

 

[jssailem]

Looking down into the area above my bilge, there is a board that holds two Group 30 batteries side by side. It worked well until my boat flooded and about 1000 gallons filled my bilge and rose a foot above the salon deck.