Battery Box Ventilation

[George H260]

Hi all,My 95 336 has two group 27 batteries stored in the cockpit aft starboard compartment. The charger is in the same compartment.I was wondering if there should be some ventilation opening in this area (presently there is none).Could gas build up to a dangerous level. Also, I do notice some odor coming from the batteries. The odor is not great but it is there. It has the smell of battery acid. I think this is normal.I only charge the batteries during the weekend. I do not leave the charger on while the boat is unattended but I plan too since I will be adding refrigeration.Any thoughts?

 

[Matt]

me too

I wish I had a solid answer for you but all I really have is a similar question. I've read some archived threads that say the hazard is combustion during charging, and that's why you vent (so to be safe, I probably would if I were you). My question, though, is: is there also a health risk due to the fumes? My house bank is in the cabin (in a locker that I plan to vent) -- should I be concerned about inhaling fumes when the cabin's closed up?

 

[Doug T.]

Hydrogen

I understand that the only fumes given off are hydrogen gas. This is MUCH lighter than air, so it should dissipate very quickly. I don't think it's poisonous.

 

[Bob]

Batteries on a 285

I have a 285 which did not come with a built in charger. I'm going to put on in this weekend. However, when I charged the two batteries, by taking them out and putting them on a charger at home, one charged up just fine but the other got hot and produce hydrogen. I was told that this is a sure sign of a "cooked" battery. We just bought the boat used (1987) last November so I don't know what the previous owner did, or didn't do, to the batteries. I suspect that leaving a charger on, while you're away, is fine as long as the batteries are in good shape. Guess the best advice I have, and I'm going to do this, is to monitor the batteries on a regular basis when I'm on the boat to see if they get hot.

 

[Dan Sheehan AMS]

Battery Ventilation

The Code Of Federal Regulation (CFR)mandates that " A vent system or other means be provided to permit the discharge from the boat of hydrogen gas released by the battery" This is regulation 44 CFR 183.420 subpart e. It is also stated in exactly the same terms in ABYC standards E-10. Most boat builders comply by simply not installing the batteries in sealed compartments. Hydrogen is lighter than air and will find a way out if there is one. High concentrations of Hydrogen gas are explosive so this is something to be takes seriously.