Battery bank located in berth area

[guyrj33]

Originally Posted by boatpoker

............

my lawyer made me include 'almost'.

[boatpoker]

Originally Posted by guyrj33

my lawyer made me include 'almost'.

Wish he'd been sleeping in my v-berth when my bow thruster battery exploded 10yrs. ago

Take a look at some exploding battery videos

[Lihuedooley77]

Just one short incident, on a long distance delivery. Race boat and race crew flew back to the U.S. to their home port. We flew to pick up the boat...the race crew partied and flew home.

Batteries were back near the quarter berth that Erica and I shared. Actually, pretty small area back in those days .

We awoke to a very strong, and not before experienced smell, It was the batteries cooking away. The boat owner and crew had left the batter charger on full power. The charger was located deep in one of the cockpit lockers and hard to see.

That was bad news, that we quickly corrected. But, just FYI. You may have batteries now that do not leak out the fumes. Technology is romping madly along at light speed.

During the pre departure sailing inspection, we found the anchor chain in one area, and the anchor in another not attached. All water tanks were empty, The auto pilot was inop, and the Satnav...no GPS ..in those days....could not hold a satilite .....

I used Coastal Piloting for our navigation, and had non paid crew and Erica and I to stand helm watches so an auto pilot was not necessary.

Never had that type of battery problem again ever, but it certainly could have turned out not so good . The fume smell was very, very evident.

We would not put a battery bank in a berthing area, due to our experience that one time. Yep, I was definitely impressed . The OP, may have a totally different set up.

[quandary]

Hallberg Rassy quite often put FLA batteries under bunks. They are in a compartment with seals and overboard ventilation.
One could play safe by not charging batteries strongly while sleeping above them to reduce amount of hydrogen produced?! Smoking in bed while a maximum charge rate is underway could yield a surprise if the batteries ventilated directly into the cabin.

[Cadence]

Why? Remember you are eliminating the weight aft and putting it forward. What about wiring length? Just some things to consider.

[guyrj33]

here's a link to a Nigel Calder article on the subject.
https://www.yachtingmonthly.com/arch...-avoid-it-3930

[Lepke]

I have several banks of house batteries, 2 under bunks. They are power vented overboard. I use a 12v bilge blower with a controller to run at a slow speed. No problems, safer than propane.

[NorthCoastJoe]

I see no problem, we have a off grid 12v solar system in our land based house the batteries are in a cabinet with high and low vents, natural convection. I think as long as you have vents it should be ok. also we have had no problems with corrosion in 20 years. And yes I have been to two battery explosions as a firefighter. One was caused by static charge, the other wrong way jumper cables. The static charge explosion happened in a closed space. If you are really concerned about gas build up put in a low power bilge blower to force air through the space while batteries are charging.

[boatpoker]

Originally Posted by Lepke

I have several banks of house batteries, 2 under bunks. They are power vented overboard. I use a 12v bilge blower with a controller to run at a slow speed. No problems, safer than propane.

Which is safer than alcohol which is safer than a CQR.

[pacific_voyager]

If sealed batteries are below waterline (or anyplace) consider slathering silicone paste (3M has an 8oz can with a brush, very useful) around the lugs and posts. This reduces or prevents discharge if underwater and corrosion if above waterline.

[Palarran]

Well thank you all for the good info. There are a lot of small details involved but I know it would really increase the performance of my cat to remove 500 pounds of weight that is currently located aft of the rudders and place it slightly forward of the mast. It might also work to split the bank and keep 4 batteries in the stern for the inverter and 6 forward for 12v.

The venting of the small amount of gas might be difficult the more I think about it. It wouldn't be a problem to vent it into the main portion of the cabin but there are no really accessible spots to the exterior from the sole of this area. There are zero sources of sparks in this area and no one smokes in the boat.

[PLANET EXPRESS]

Do not know what kind of sailboat you got but batteries are very heavy usually and you should consider the weight you will be putting forward could create like a weather helm?

[waterman46]

Originally Posted by Palarran

This situation is a little different as the thick heavy wire right now is running from the stern about 50' forward to my 12v distribution panel. By moving them the lead wire would be about 8'. It's also still about 14' back from the bow. My sterns are very heavy due to extra equipment installed in the aft compartments. This would definitely help with the balance of the boat and also move the weight lower in the hull. Access is very good and I can have a secure platform installed for the batteries. I'm just not sure how to go about venting the bank. And, is there a danger to having them in below the waterline and in a berth in general.

No danger if they are AGM type (sealed). Below waterline is preferable to keep weight low. Since your distribution panel is forward, moving batteries closer will be a real improvement - assuming you have a separate engine and generator starting battery close to the engine room. Our AGMs are located under a pilot berth amidships. Your shorepower/generator battery charging system should include battery temperature sensing to avoid any real problems.

Hydrogen gas is so light it dissipates very quickly once outside the battery compartment. There is no way you could trap enough hydrogen in concentration sufficient to have an explosion in the general cabin area given the small amount of hydrogen generated from the normal size FLA bank, and sealed AGM completely removes that issue anyway. Now, if you hear your voices getting really high (hydrogen will cause that!) then you'll know to stop smoking!

That said, the pitching inertia may slightly increase, but I really doubt you could notice it in the size of your yacht.

[stormalong]

Originally Posted by waterman46

Now, if you hear your voices getting really high (hydrogen will cause that!) then you'll know to stop smoking!

I Think you have hydrogen and helium mixed up.

[john61ct]

If you design for increased ventilation within the living space, rather than sealing up the battery space, eliminate the safety issue.

Some people are too sensitive to the smell, but I'd wait and see before taking complex measures