Battery Boxes - should they be ventilated?

[rafiki_]

Phil, the battery box is there to restrain the battery, so it doesn't get mobile on the water, and to contain any potential leak or explosion. That is why the box should be vented. On my old sportscruiser, the boxes vented into the engine bay by not being sealed. They did the job of constrain and restrain and met the BSS requirements, but not a "proper" job, which is to vent out of the hull through a gland.

 

[jac]

I would be really cautious about relying on blower fans in the engine bay to vent the hydrogen.

If any has collected in their, exactly how sure are you that operating any switch won't make a spark. Would you go looking using a match? Rely on it's lighter than air properties and passively vent it.

 

[markc]

I would be really cautious about relying on blower fans in the engine bay to vent the hydrogen.

If any has collected in their, exactly how sure are you that operating any switch won't make a spark. Would you go looking using a match? Rely on it's lighter than air properties and passively vent it.

Blower fans should be spark protected and also Hydrogen Sulphide is denser than air

 

[jac]

Blower fans should be spark protected and also Hydrogen Sulphide is denser than air

True.

But IIRC charging batteries will produce Hydrogen not hydrogen Sulphide.

And whilst the blower fans might be spark protected, what about everything else?
Scenario. Boat left moored whilst you go ashore for the day or M-F, connected to shore power and batteries are charged producing some gas. You get on board and start turning equipment , batteries on. 100% sure that none of it produces a spark?

 

[markc]

True.

But IIRC charging batteries will produce Hydrogen not hydrogen Sulphide.

Overcharged batteries can definitely produce hydrogen sulphide