Batteries in the bilge ?

[OldManMirage]

If this has been addressed better elsewhere please point me to it.

Ok, so on my Cape Dory 28 my batteries are currently in the cockpit lockers. I have a group 27 Starting batt on port and 3 group 31's on starboard.

I believe I have enough room to move them under the cabin sole. Better weight distribution, more room in cockpit lockers, putting in-used space to better use. Right now my access is only 2 small lift-out hatches but that can be modified as needed for better access. They are wet-cell batts and I intend to stay with that as I plan to be mostly on solar.

My question - is there anything I'm not thinking of here ? I know plenty of boats have their batteries in bilge areas. What I specifically think of is the fact that my bilge is small, and while this area NORMALLY remains dry, if I encounter problems (heavy weather, leaks) there could potentially be seawater sloshing around them for periods of time.

Thoughts pro and con would be appreciated. I can always leave them where they are !

[uncle stinkybob]

Originally Posted by OldManMirage

If this has been addressed better elsewhere please point me to it.

Ok, so on my Cape Dory 28 my batteries are currently in the cockpit lockers. I have a group 27 Starting batt on port and 3 group 31's on starboard.

I believe I have enough room to move them under the cabin sole. Better weight distribution, more room in cockpit lockers, putting in-used space to better use. Right now my access is only 2 small lift-out hatches but that can be modified as needed for better access. They are wet-cell batts and I intend to stay with that as I plan to be mostly on solar.

My question - is there anything I'm not thinking of here ? I know plenty of boats have their batteries in bilge areas. What I specifically think of is the fact that my bilge is small, and while this area NORMALLY remains dry, if I encounter problems (heavy weather, leaks) there could potentially be seawater sloshing around them for periods of time.

Thoughts pro and con would be appreciated. I can always leave them where they are !

Seems you answered your own question. water in the bilge could kill your batts and you lose electrical, bilge pumps, nav electronics, vhf, nav lights. If you can live with that, your choice.

[Terra Nova]

You can keep water off the batteries' electrical connections simply by installing a very deep-skirted cover (like an upside-down battery box). Cables would necessarily have to exit under the bottom lip of said cover. Air trapped inside this cover prevents water from rising to the level of the battery tops.

[OldManMirage]

Now that's an interesting thought Terra Nova. I could just use standard battery boxes and mount them upside down.

As I say my main concern is when something goes wrong. The more I think about what I've seen on other boats as far as battery installations go, I don't think my idea is a bad one. If I were to have that much water in the boat there is definitely a problem. And if I couldn't get it under control in a reasonable amount of time it would be because it's a disaster of such proportion that I'm probably abandoning ship anyway.

I may just mount the house bank there and leave the starting battery where it is. It's a thought.

[Kelkara]

Originally Posted by Terra Nova

You can keep water off the batteries' electrical connections simply by installing a very deep-skirted cover (like an upside-down battery box). Cables would necessarily have to exit under the bottom lip of said cover. Air trapped inside this cover prevents water from rising to the level of the battery tops.

That will also trap any hydrogen released by the battery. risk of explosion?

[Cheechako]

Water shorting out may be an issue. However, you could put your house batteries in the bilge, and reserve a pump and engine battery(s) up above in the locker.

[chris95040]

Terra Nova, that's a really interesting idea.

I have a deep deep bilge that I've been afraid to put the batteries in even though it'd make a lot of sense for weight + space usage.

I'd still be afraid that in an oh-crap scenario, the sloshing around, etc would allow the air to burp out of that space though.

[Terra Nova]

Originally Posted by Kelkara

That will also trap any hydrogen released by the battery. risk of explosion?

That might be a risk.

[Pendragon35]

I have an Alberg 35, a similar design. Two batteries in the top of the deep bilge. I hate this arrangement. Once, when I did something stupid that pierced the PSS coupling and let water above the floorboards, I killed the (original) batteries) sEcond, to get to the bilge I have to pull the batteries out.

Ironically, I'm considering redoing things to make it like what you have now: batteries in the lockers above the floor, one on each side.

[hellosailor]

Aside from water or damp affecting the connections and circuit, if any sea water gets into the battery itself, that will liberate free chlorine gas. Which is not a very good thing. So if you do decide to relocate that way, you'll want to make Real Damn Sure the battery compartment is a sealed and vented compartment, and ask yourself what would you do if seawater got into them, and you had to ventilate or evacuate immediately.

Not an issue if you switch to AGM or gel, sealed batteries.

[OldManMirage]

Yeah, I think I've heard enough to convince me to leave them where they are. There just doesn't seem to be enough pros to outweigh the possible cons.

Plus, it's a Cape Dory. By and large they are pretty well thought out boats. If it would have been better to stick the batts in the bilge they would probably have already done so !

I will likely rearrange them a bit, but no sense in reinventing the wheel eh ?

[ZULU40]

Originally Posted by Kelkara

That will also trap any hydrogen released by the battery. risk of explosion?

there is some hydrogen gas, but if a cell fractures or the battery case is compromised sulphuric acid and sea water makes chlorine gas which is a greater risk. Its a terrible way to die and it isnt fast.

Id keep batteries above sea level

[Locquatious]

Our boat was knocked over in Irma. We had AGMs. The cables blew off at the battery bolt connections when water pooled on the boat low side. Don't know if the batteries were shot. No evidence of battery leaking.

[Pete7]

My only query would be do you really need 3 x 31 type batteries for a house bank on a 28ft yacht? We manage with a pair and that includes TV occasional heating, lights and laptops etc.

Pete

[Seighlor]

My last boat had a deep bilge with battery boxes beneath the floorboards (Original design).

Twice, in rough sea conditions, water entering at the windlass accumulated to the extent that the batteries were completely immersed. In the first instance, sailing alone, the battery terminals were eaten away from the cross current before I became aware of what was happening.

The second time, with crew aboard, we caught it early. I was able to start the engine, even with the batteries immersed, and we used the engine's raw water pump to evacuate the bilge.

In terms of weight placement, batteries in the bilge may be a good thought. Other than that, maybe not such a good idea.