Strange Rotten Egg Smell from Diesel/Battery Pack

[Greg McKenzie]

Our B 331 has developed this putrid stink after the 27 hp Westerbeke diesel has been running for a few hours and we cannot determine where it is coming from.
There are no visible drips, the 3 house batteries are brand new, there is no residual battery acid, and when connected to AC shore power our Xantrex charger brings the batteries up to 13.2 volts comfortably.
Stating the obvious, the head is also empty when we investigate the root of the issue.
Any thoughts?

 

[Rich Stidger]

If the batteries are new, it probably isn't this, but check that there is a proper level of electrolyte in the batteries and that they are not dry.

 

[RonRelyea]

hot water heater? maybe your pressure relief valve is "relieving" itself ...

 

[anchorclanker]

Rotten egg smell is generally sulfur, and most likely source is sulfuric acid from the batteries, which may be getting overcharged. Just because your not seeing acid doesn't mean they arent venting gases. While you can easily smell the sulferic acid rotten egg smell, you cannot smell the hydrogen gas that is produced at the same time.

You really need to solve this because it could lead to something quite disastrous out away from the dock. As above, check your electrolyte levels. If they are new batteries and you see the levels down, thats a sure indication of overcharging boiling them dry. They can get rather low before youll often start seeing capacity problems.

 

[chp]

Possably you voltage regulator on the alternator is faulty and overcharging the batteries. Definately check the fluid level on the batteries.

 

[Greg McKenzie]

This is a great answer, makes sense, and is something I suspected.
I will follow up on your suggestions.
Thanks, Greg

 

[gpd955]

Did you check the fridge just to make sure there aren't any rotten eggs in there?? Just kidding.

I'd definitely check the water heater. Had the same problem last year and before i replaced the element I emptied and ran fresh water through the system and the smell went away. Now I make sure my hot water is used more often. Haven't had a problem since.

 

[MLampner]

Though unlikely, salt water can react with battery acid to produce Hydrogen Sulfide, aka the rotten egg smell, while the regulator is the most likely culprit a deck leak and salt spray could be an alternative if the drip is just the wrong place. In either case as previously pointed out there is both an explosion risk, the outgasses are combustible and the risk of suffocation if bad enough, though the smell would likely drive you on deck before that was a risk.

 

[Greg McKenzie]

Though unlikely, salt water can react with battery acid to produce Hydrogen Sulfide, aka the rotten egg smell, while the regulator is the most likely culprit a deck leak and salt spray could be an alternative if the drip is just the wrong place. In either case as previously pointed out there is both an explosion risk, the outgasses are combustible and the risk of suffocation if bad enough, though the smell would likely drive you on deck before that was a risk.

All good observations....however we are a fresh water boat so we can rule out the salt water angle.

 

[SEMIJim]

Sounds to me like battery over-charging.

Jim

 

[CD60]

Just want to know:
1 has the ground wire sparked or shorted at any time?
2 Has the volts out put been checked on the alternator
3 Does it have a built in alternator

Might be over charge situation from the alternator

 

[Benny17441]

New batteries! I cast a vote for the water heater as the culprit. You may need to flush it out with a chlorine solution.

 

[Greg McKenzie]

Just want to know:
1 has the ground wire sparked or shorted at any time?
2 Has the volts out put been checked on the alternator
3 Does it have a built in alternator

Might be over charge situation from the alternator

Answers:

1) no short issue

2) this has not been checked

3) yes, built in alternator

 

[Stu Jackson]

Of course, the alternator is "built-in." Not sure what that means. Perhaps they're asking if you have an internal or external regulator.

Check the alternator output voltage when running (that's what they mean by the regulator).

Rotten eggs from hot water heater: http://c34.org/bbs/index.php/topic,5836.0.html Jack's right, use the hot water faucet even if you don't have hot water to keep waster moving through the heater, just a good habit to get into.

 

[Witzend]

When you charge a battery electrolysis breaks the bond between the O and the H thus emitting these gases. By themselves you would smell nothing. Rotton egg smell is usually Hydrogen Sulfide, H2S is a byproduct of http://en.wikipedia.org/wiki/Bacteriabacterial breakdown of http://en.wikipedia.org/wiki/Organic_matterorganic matter in the absence of oxygen. Not likely to have anything to do with your battery. I would be looking for a hot water leak and checking the quality of the water.

 

[zeehag]

overcharging batteries.