×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

hydrogen off gasing from sealed lead acid batteries

hydrogen off gasing from sealed lead acid batteries

hydrogen off gasing from sealed lead acid batteries

(OP)
Hi All,

We have a battery pack made up 6 sealed lead acid batteries to make a 12 volt battery, our customer has requested the ability to charge this battery in a sealed hull.  We currently recommend charging outside of the hull for this reason.

My questions are the following:

1.  Does anyone know of a purging system that could be used to purge the hull incase of off gassing may occur?

2.  Does anyone know about a catalytic scavenger in the battery compartment to adsorb the hydrogen?


Thanks for any information you can provide.

Tofflemire

RE: hydrogen off gasing from sealed lead acid batteries

Wouldn't recommend sealing it in. Hydrogen can make a big bang.

You should adequately vent using a flameproof fan, with anti-spark features etc.

Try ABB-Woods ltd fans

Friar Tuck of Sherwood

RE: hydrogen off gasing from sealed lead acid batteries

We use some bilge purge fans here at work for a similar use.  It is common to find ones rated 'explosion proof' since they are often used to vent fuel vapor.
Though you might want to give some thought to fire suppression in this enclosed space.

= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.
http://www.trenttube.com/Trent/tech_form.htm

RE: hydrogen off gasing from sealed lead acid batteries

This is a SEALED hull, right?  As in submarine?  As in a fan is not really a practical idea?

There probably is a substance that could absorb the hydrogen or react with it more slowly than oxygen does, but I don't know what it might be.

Besides dilution, one other way to prevent a fuel gas from combusting is to remove the oxidizer.  Prefill the compartment with hydrogen.


Mike Halloran
NOT speaking for
DeAngelo Marine Exhaust Inc.
Ft. Lauderdale, FL, USA

RE: hydrogen off gasing from sealed lead acid batteries

The truely sealed batteries have getter material inside of them.  And they are welded into metal cases.
How about a nitrogen purge?  The gas is cheap, a small pressure bottle, regulator and pressure switch would work.  But the space would need to really be sealed.

= = = = = = = = = = = = = = = = = = = =
Corrosion never sleeps, but it can be managed.
http://www.trenttube.com/Trent/tech_form.htm

RE: hydrogen off gasing from sealed lead acid batteries

Couple thoughts
1.  The batteries are supposedly sealed.  If so how does the H2 get out?

I am just a former nuclear submarine electrician - we had 5,000 AH 250 volt lead acid battery and yes we generated H2 and ys we were concerned - that is why we had two H2 detectors, a battery well exhaust fan, adn two H2 burners.

IF we had the diesel running (rarely) we could take a suction off the battery well and run the H2 thru the engine.

DO NOT seal this battery box -
how do you access for maintenance
how do you prevent condensation?  this is a boat you WILL get condensation

VENTILATE the box.  
Use a blower to blow air IN
-- dont need to worry about H2 igniting in the blower and you avoid stagnation and gas pockets in the bos
and exhaust the box at a safe place or take a suction and run the gas thru the engine.

Dan Bentler

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources