battery venting

[Jonas]

Transport Canada "Construction Standards for small vessels" states: "Spaces containing batteries shall provide for the escape of
hydrogen." My plan has been to install the batteries for the Welsford-designed "Penguin" forward of the centreboard case underneath the forward berth. The only ventilation that has been designed into this space are opennings in the bulkheads at "floor" level, and berth tops that open (however, the berth will be covered by a cushion unless access is required into the battery locker or other storage lockers in that area). The plans call for trim ballast in this area in any case. I could build in a vent hose connecting the locker to the outside. Other ideas appreciated for making this installation compliant with the regulations.
Cheers,
Jonas

[Gary E]

My plan has been to install the batteries.... underneath the forward berth. You gona sleep there?

Put the batteries back where you have the engine and it's ventilation.

In case this boat is so small as to not have an engine, why do you need BATTERIES?

[Ian McColgin]

Hydrogen rises. Just don't have a vapor proof top on the battery boxes. Depending on the boat's construction, the hydrogen may find its way out between the hull and the ceiling or you may want to have a bit of a gap under the berth's fiddle board.

Even in the small space of a boat's interior, this amount of hydrogen is not dangerous. It's dangerous when confined to the battery box - really just a few cubic inches of space not filled with battery - and mixes with a little oxygen. Hydrogen is most enthusiasticly made during over-charging, which also heats the battery . . .

Edited to add: You want the bottom and sides of the box sealed to prevent any acid overflow from wantering about. Unlike propane lockers, battery boxes are vented at the top and it need not go overboard.

[ 01-17-2006, 01:56 PM: Message edited by: Ian McColgin ]

[Invader]

You could also go to a dry cell battery AGM or such.

Willy
Invader No 1
39 Kishi Conversion

[NorthLight]

We had big batteries, that weighed as much as your car, on the submarine that I served on. Given that your boat battery is much smaller than those on the sub, I wouldn't worry about buildup of hydrogen gas. Like stated before, hydrogen will buildup most with rapid charging. The alternator off your engine or a trickle-charger is not going to rapidly charge your battery. The only way the hydrogen would stay there is if it was an air-tight space, which it doesn't sound like it is.

[kc8pql]

I used one of these, which you can get here:
www.yandina.com/NewCatalog.htm (http://www.yandina.com/NewCatalog.htm)
Look under Automatic Battery Vent

http://tinypic.com/kei3yo.jpg

[Jonas]

Thanks for your responses. I suppose that something like a computer fan mounted in the area of the battery locker would be sufficient, and also provide the bonus of helping to keep the area dry.

[JimConlin]

If charging is to be done by an outboard's alternator or by a solar panel or trickle charger, the current involved is so low that the hydrogen is truly negligible.

I've never seen specific attention to battery hydrogen in boats with up to 100 amp alternators, much larger than yours.

[kc8pql]

Originally posted by JimConlin:


I've never seen specific attention to battery hydrogen in boats with up to 100 amp alternators, much larger than yours.Yeah, I should have added above that I have a 600 amp hr battery bank, 140 amp alternator and a 2000 watt inverter/charger. If you're talking about an outboard boat, I wouldn't worry much either.