Battery Locations

[42AFJ]

We have been looking to place our battery bank below the cabin floor. Now they are in the engine room on the port side and I am sure they are part what makes the port side heavier. This would be a cooler place for the batteries as well I would think. Any thoughts?

[s/v Jedi]

For weight distribution: they should be below the waterline to help as ballast (not on cats of course, you can't have batteries on cats as they slow you down ;-)

Further considerations: support for their weight, access for maintenance, securing them so they stay in place, vented box. Pls. kick in what I forgot.

About port side heavier: do you list to port? Just put the same amount of weight (one or more persons) on the same position on starboard to see if that cancels it.

cheers,
Nick.


cheers,
Nick.

[Marinheiro]

An interesting point about battery location - the safety regs in NZ specifically require the batteries be located "above the cabin sole".
I know the normal practice in USA is below the sole.
Reinforcing Nick's comment, good ventilation both for cooling and disappation of gas, esp for wet batteries

[42AFJ]

Below the sole I have planned to build a box that would rise up to boards and venting is provided through the teak grating in the galley. Of course being in the engine room now it is quite hot and not the best ventillation.

[SabreKai]

On my smaller boat Espina, the starter battery is located in a tray on the port side of the engine bearers. The other batteries are located in a hanging rack which sits inside the keel. Being steel with lead ingot ballast, there is a lot of space in the keel, so they made up a rack for 4 batteries end to end. They hang down into the keel area and are about 6 inches below the cabin sole. The rack is a steel strap frame basket which is bolted to the extra lower chine skin which over hangs the keel can on either side. The batteries are all strapped in place, and can not move or fall out in case of a roll over or pitch pole.

Sabre Dance, has two batteries in a box on the stbd side of the engine bearers. Being steel but ballasted with cement and steel punchings, I"m going to chisel out a space to do the same. I figure i have sufficient space for 3 length wise, but 6 width wise if the keel is wide enough. I'll have to measure it to be sure.

I like the idea of keeping the 60-75 lb batteries as low as I can.

Sabre

[quidam]

While having the batterys down really low is good in theory, imagine what would happen with a little water in the bilge. My rule is that the only thing electrical that a foot of water in the bilge gets to is the bilge pump and the shower sump.

[boatpoker]

ABYC "Storage Batteries" Standard E-10 recommends and TP1332E requires in part that batteries be vented outside of accommodation spaces and that batteries be secured so as not to move more than one inch in any direction, be contained in boxes or trays resistant to electrolyte, that positive terminals be protected by dielectric material and prohibits wing nuts as a means of securing conductors.

Batteries release hydrogen when charging. Remember the Hindenburg ?.

[hugosalt]

Have considered moving batteries to below the cabin sole, two concerns have stopped me so far...distance from motor/charger etc. (8-10 ft.) what gauge
wire to use? ...and although area is dry, if it would get wet... might be a problem
just when I really need them.(batteries are not sealed.)

[HorizonMarine]

Use AGM's and gassing problem is gone. Battery boxes can be gone. And you can put them in any orientation (except upside down) without loss of power. (AGM's not gels). I found I lacked height, but had width so layed some 6v on their side.

[Celestialsailor]

Originally Posted by 42AFJ

Below the sole I have planned to build a box that would rise up to boards and venting is provided through the teak grating in the galley. Of course being in the engine room now it is quite hot and not the best ventillation.

I'm reading this that you might be venting the batteries through the grate in the galley inside the boat which would not be a good idea. Batteries give off Hydrogen...very explosive. Normally they are vented outside the boat. Assuming that they are below the sole and close to any bilge water, they should be in a sealed plastic, or other suitable material, box with a lid and vented via hose to an outside vent/thruhull.

[Steve Pope]

I guess the thinking behind why batteries have to be above the floorboards is required in NZ is that for at least the last 40 years or so almost all the popular designs are cruiser / racers with fin keels and 6 foot draught therefore they have no real bilge area at all. A litre or 2 of water can slosh around a lot as there is generally only a minimal sump to locate an electric bilge pump at the lowest point. Also the Cat 1,2 & 3 rules are based on racing regulations hence the lack of allowance for the more traditional designs that have more substantial bilge areas.

[42AFJ]

Where I am looking to relocate the batteries there is about 24 inches of height from bottom of what would be a battery box to floor board. The water would still have about 6 inches to drain under the battery box back to the aft bilge where all water collects and the pump kicks on. Sure there is the scenario with water above floorboards that I have thought about. Given the large bilge... that is a lot of water. And the run to the charger and engine is less than 3 to 4 feet. If I could find a very low draw computer type fan to help vent to engine room this would of course be ideal. Otherwise there will be a vent running back up to the engine room to vent outside. Thanks to all

[bobfnbw]

A proper battery box should keep water out of the batterys, unless your seriously in trouble, and then... I don't think some hydrogen gas venting into the interior is a big deal, as we would all be on deck, pumping out with the edson pump, and getting ready to head over the rail to the life raft.
On a Endeavour 40, there is a 36" sump over 80" long and another below the sole area that is quite large, and that is where our batteries will reside soon. They are being moved from the engine room that was of course to warm, and access was poor.
So for our situation, I would have 43" of water in the boat. Yeah I guess its still salvagable, but with that much water coming in, might be a non issue.

I agree that AGM's are better in this regard than flooded. I would not put them on their side. I read somewhere that you lose 15% of capacity doing that.

IMHO, the lower the better.

[Marinheiro]

The problem with batteries gassing is not just the Hydrogen (which is explosive), they can also vent off other gases such as stabine and arsine - very nasty indeed.
Ref the NZ cat safety regs - speculating the above floor requirement may have evolved from the fact that the usual time you discover you have a leak is when you come down below or sit up on your bunk and find your feet in water. Know this from 2 experiences - a tri travelling at high speed with water coming over the top of the dagger board case and another time during a gulf race when a mate had not closed the dry bowl valve and a siphon was set up.
Before my yacht goes back in the water there will be at least 1 bilge alarm installed.

[DeepFrz]

I don't think some hydrogen gas venting into the interior is a big deal, as we would all be on deck, pumping out with the edson pump, and getting ready to head over the rail to the life raft.

Bob, it's not hydrogen gas that you have to worry about. It is Chlorine gas that will get you.

Since the container is not sealed, great care has to be taken to ensure that the electrolyte does not come into contact with you (burns!) or seawater (chlorine gas!).

http://www.vonwentzel.net/Battery/01.Type/index.html