sulfur smell from dying battery?

Hey everyone
Went down to the boat today and first thing I noticed is horrible rotten egg smell when I walked inside the boat. I initially thought it was coming from my holding tank vent so I crawled into the ER take a look around where I noticed the battery box holding my 4D start battery was really warm.
1.So my first question is can a bad battery be causing a sulpher/rotten egg smell?
The boat would not start due to a dead batterie.
2. Is it normal for the battery box to be warm to the touch?
3. I currently have a 4D. What's the difference between a 4D and 8D?
4.I plan on replacing it tomorrow. Any advice or suggestions?

Thanks!

Yes dead overcharged batteries smell of rotten eggs. I would think you might want to check your charger to see if it is overcharging.

The start battery is 5 yrs old, so it's probably time to replace it. And the charger seems to be doing an ok job with the house batteries. No issue there.

Tunajoe said:

Hey everyone
Went down to the boat today and first thing I noticed is horrible rotten egg smell when I walked inside the boat. I initially thought it was coming from my holding tank vent so I crawled into the ER take a look around where I noticed the battery box holding my 4D start battery was really warm.
1.So my first question is can a bad battery be causing a sulpher/rotten egg smell?
The boat would not start due to a dead batterie.
2. Is it normal for the battery box to be warm to the touch?
3. I currently have a 4D. What's the difference between a 4D and 8D?
4.I plan on replacing it tomorrow. Any advice or suggestions?

Thanks!

Click to expand...

I take it your batts are wet cell?? In adition to checking your charger for correct operation... I recommend you check your batt cells at least once every six months and keep them close or exactly at correct level with distilled water only. Even if charger is working well when a batt's water level drops below its lead plates much can occur regarding sulfer smell, sulfating crystals forming, and excessive battery heat occurring. I've heard of, but not personally seen, wet batts with exposed plates that when still receiving a charge burst into flame.

I recommend you get new batts!

Good Luck! - Art

Do you have two batteries in parallel?

1.So my first question is can a bad battery be causing a sulpher/rotten egg smell?
Yep sulfuric acid. You may find acid in your box. Have a box of baking soda to neutralize the fluid in the box.
2. Is it normal for the battery box to be warm to the touch?
Batteries will heat up under heavy charge. They will get very hot with shorted cells and boil dry.
3. I currently have a 4D. What's the difference between a 4D and 8D?
A 4D is 125 lbs and 190-200 amp-hrs. The 8D is 165 lbs and 220-230 amp-hrs.
4.I plan on replacing it tomorrow. Any advice or suggestions?

This is a typical thing to happen. The battery or batteries get a little warm and some of the water evaporates. Then the charger keeps them on charge because the voltage is low. Then the battery or batteries cook. That is one reason that I don't stay plugged in. I plug in when my battery monitor tells me I need to. Once you develop a pattern, you will know. Every 3 days, or whatever it is, I need to plug in for 24 hours. A good solar panel is great to keep a trickle charge on the batteries. I have cooked a few batteries myself. Be careful, if they are those maintenance free batteries, they get all swolled up (as Danny DeVito says in Twins) and could explode. Wet cells will vent, that's why you smell them and that's why the water level is below the plates. Once the batteries cook, they are done. I did get another season from my cooked batteries. I had a Link 2000 and they have a descaling feature that takes 8 - 10 hrs. You MUST follow the owners manual exactly and the boat will smell. But, like I said, I did get 1 more season out of the house bank. Maybe your charger or monitor has that feature?

Sounds like you were lucky to not have an onboard fire.

This is a new to you boat. It has been neglected for awhile and appreciates the TLC it is now receiving. Many systems to learn and things to verify including the charging system. Check the battery for electrolyte level and a dead cell, if level OK and no dead cell dig deeper than a worn out battery. Have your charger and overall electrical systems checked out by a very good certified marine electrical tech.

Were the batteries disconnected for the overland journey? What brand and age is the charger?

Replace the battery with a 4D. Most likely a bad battery. Watch the new battery for a few days to make sure the new battery water is not boiling or the battery is not hot to touch. Warm is ok while charging. It's not rocket science.

Scary said:

Replace the battery with a 4D. Most likely a bad battery. Watch the new battery for a few days to make sure the new battery water is not boiling or the battery is not hot to touch. Warm is ok while charging. It's not rocket science.

Click to expand...

Quite correct Steve!

But, after all... it is... The "Science" of Owning a Boat!

Happy Boat-Owning Daze! - Art

My charger used to charge two banks of different capacities and the smaller bank always died much faster. I've since disconnected the smaller bank from the charger and have used a Xantrex Echo charger with great success. What I found out is that even though my smart charger is a 3-bank charger, it doesn't stop charging banks independently - making it not very smart. The smaller bank is constantly overcharged since the charger keeps charging until the bigger bank is full. Another option that I considered was to install another charger but the echo charger was cheaper and less work to install.

Do you need a battery that big to start your main?

I get by just fine with 2 Group 27 1000 amp cranking batteries (paralleled) and that's over twice the required power per the engine manufactures recommendation. Cheaper, lighter, easier to replace. My house is 8X6v golf cart, Genset is also a group 27.

I understand the need with 12+ liter trucks and heavy equipment the need for a 4 or 8 D but only the really large engines starting up on winter days require that much power imho.
Ford/Sabre 120

Art said:

I take it your batts are wet cell?? In adition to checking your charger for correct operation... I recommend you check your batt cells at least once every six months and keep them close or exactly at correct level with distilled water only. Even if charger is working well when a batt's water level drops below its lead plates much can occur regarding sulfer smell, sulfating crystals forming, and excessive battery heat occurring. I've heard of, but not personally seen, wet batts with exposed plates that when still receiving a charge burst into flame.

I recommend you get new batts!

Good Luck! - Art

Click to expand...

Thank you Art.
Yes they are wet cell.
You scared me about the fire, so I drove back to the boat and turned off the charger.

bayview said:

Do you have two batteries in parallel?

Click to expand...

No sir. My battery bank is one 4D start and (2) 6volt batteries in series for the house.

fryedaze said:

1.So my first question is can a bad battery be causing a sulpher/rotten egg smell?
Yep sulfuric acid. You may find acid in your box. Have a box of baking soda to neutralize the fluid in the box.
2. Is it normal for the battery box to be warm to the touch?
Batteries will heat up under heavy charge. They will get very hot with shorted cells and boil dry.
3. I currently have a 4D. What's the difference between a 4D and 8D?
A 4D is 125 lbs and 190-200 amp-hrs. The 8D is 165 lbs and 220-230 amp-hrs.
4.I plan on replacing it tomorrow. Any advice or suggestions?

Click to expand...

Thank you!

sunchaser said:

Sounds like you were lucky to not have an onboard fire.

This is a new to you boat. It has been neglected for awhile and appreciates the TLC it is now receiving. Many systems to learn and things to verify including the charging system. Check the battery for electrolyte level and a dead cell, if level OK and no dead cell dig deeper than a worn out battery. Have your charger and overall electrical systems checked out by a very good certified marine electrical tech.

Were the batteries disconnected for the overland journey? What brand and age is the charger?

Click to expand...

I initially checked the Electrolyte levels on all the batteries and they were good.
Boat started first few weeks no problem and then one day it didn't.
So I checked levels again (good) and terminals to see if they were loose (they were). I tightened them up and then 2 days later, boat started normal.
I figured problem solved.
Then the smell started, which I thought was the holding tank.
No wonder the tank deodorizer didn't work
Batteries were not disconnected for the transport.
I believe the charger is a xantrex? It is original to the boat so that puts it at 10 years old.
Today, I'll put a meter to it and see what it's putting out.
Thank you!

SCOTTEDAVIS said:

Do you need a battery that big to start your main?

I get by just fine with 2 Group 27 1000 amp cranking batteries (paralleled) and that's over twice the required power per the engine manufactures recommendation. Cheaper, lighter, easier to replace. My house is 8X6v golf cart, Genset is also a group 27.

I understand the need with 12+ liter trucks and heavy equipment the need for a 4 or 8 D but only the really large engines starting up on winter days require that much power imho.
Ford/Sabre 120

Click to expand...

I have no idea if I could start threading with a smaller battery.
Probably. It sure would make things a lot easier to instal a smaller, lighter , batterie!
Of course, I still have to hump the 4d out of the engine room by myself today.

I downsized to a (for lack of a better number as this had a goofy number I never heard of) Group 31 to start my 120 Lehman.

It had something like 900 CCA so I wasn't worried and it has been fine for the last 700 hours of ops.

Downsized from an 8D.

Group 31 are a common start battery in the trucking industry. Pretty common set up on a truck with a 15 liter engine (915 cubic inches) would be 3 group 31 batteries which will crank and start the engine even in fairly cold temperatures. Your Lehman is (at most I think) 380 cubic inches and so I am not surprised that a single group 31 does the job. In my view the best part is the 31 s are such a common size that the price stays reasonable.and they are available almost everywhere- even your local Wal-Mart probably carries them.

As house bank and engine starters... Been using four (4) wet cell Group 31 Deep Cell Marine Batts from "BatteryPlus" store for years. East Penn built, high quality, inexpensive, no problems, easy to maintain, charge quickly, and... collectively supply plenty of power. Also have a gen set Group 27 starter batt... and... a completely independent Group 27 deep-cell/starter combo batt that's in separate batt box. I keep it 100% charged in wait for if all else fails; basically it acts as a fool-proof safety feature!

We're very efficient on how elect power is used aboard boat. At anchor for long as we want gen set usually runs about .75 hr in morn and .75 hr in eve. That keeps all batts charged, AC refrigerator/freezer cool, food cooked, coffee perked, water hot, 2 computers/2 cell-phones charged, recharged batts on low level cabin lights... and what ever else we need... like occasionally portable power tool batts charged. Oh, and that includes our 5 mile walkie talkies.

Cost for whole set up from BatteriesPlus was under $650... inc all batts, 2 battery testers, a trickle charger for independent safety batt and its seperate batt box. Over 5 years now and it all is still going strong!

BTW...

I never leave my boat plugged into dock when away from boat for any extended periods (i.e. one 24 hour day or longer). Always keeping boat completely isolated from any contact with dock and making sure that batts aboard are isolated from boat via Perko mains. This makes certain boat gets little as possible corrosion/galvanization/electrolysis to metal portions; I do keep a float switched bilge pump direct-wired to house bank. The only down side to this is that "if" boat suddenly sprung a consistent and sizable leak the batts would eventually go dead, direct wired pump would go quiet... sinking boat sounds such as Blub, Blub, Blub might be heard if no person on dock took actions before boat sunk - That's why I carry insurance!

In my experience of many decades... Wet cell batts do NOT need to constantly be kept to 100% charge. Especially deep cell type. Long as bats are not left long enough that they go below 50% +/- charge, and they have plenty electrolyte in each cell, they are just fine to let stand. Then when visiting boat - turn on charger and bring batts up to 100%. I have gone up to 4 months between visits and found that batts remained at 60 to 70 percent charged. Upon visit I always make certain all batts are at 100%. I'd guess that even six or a little more months would not be way too long between recharge. Because batts do loose charge even while sitting isolated and dormant... there is a limited period of time between which recharge should be accommodated.

Matter of fact, I believe the constant hookup to chargers, therefore non stop charging and recharging of batts (at least wet cell type - which I use) reduces their overall life span.

For even more safety value I've solar panel on front of fly bridge that trickle charges to gen set batt when out and about. That way if all else failed I could restart batt charger. And, as last step caution, I keep sturdy jumper cables aboard too.

A sulphur smell coming from a battery is a strong indication of coming disaster ... Turn off the charger, don protective gear and disconnect immediately.

In my experience of many decades... Wet cell batts do NOT need to constantly be kept to 100% charge.

Ditto here Art. When I arrive at the boat I turn the engine room blowers on first to "hear" how charged the batteries are- then turn on the charger. For me it's a quick way to prove the batteries are still holding up.


1983 Present 42 Sundeck
Twin Lehman 135's

Well, I changed out the 4D battery today and it was easier than I thought.
I was able to muscle the old one out and not make a mess of anything. I then cleaned the battery box carefully.

I ran down the local chandlery and purchased a new 4D for $189.00. Installed it and I'm back up and running.

My good friend who also has a 32' NT came down to the boat and was able to clarify a few questions I had regarding the house and start batterie.

It was interesting that the old start battery had dry cells. I had checked them a week before the smell and before I tightened the terminals. At that time they were all normal.
I do wonder if the charger is working correct. I know the settings are correct because NT has a sticker telling you what they should be.

I did turn on the charger before I left today, but regret that now.
I think I'll run down tomorrow and turn it off.
I think I'll just leave it off and develop a system like Forkliftt.

Thanks for everyone's help!

While modest "off the charger" time can be tolerated....marine batteries are usually a good example of what I have experienced that "over charging" and "under charging whether voltage or storage without trickle" cause their early demise.


Lead acid batteries must always be stored in a charged state. A topping charge should be applied every six months to prevent the voltage from dropping below 2.10V/cell. With AGM, these requirements can be somewhat relaxed.
Charging Information For Lead Acid Batteries – Battery University


The problem with boats is there always seems to be stray current floating around....if you disconnected your batteries every time you topped them off...it may not be an issue. Otherwise the gads of devices to keep your batts topped off all the time would become just anther form of "snake oil"...and yet I rarely hear it discussed that "good" trickle or auto weekly charger checking and topping chargers as "snake oil".

Thank you psneeld for providing link. I read entire page and feel that, in summation, the quote at bottom is most comprehensive for understanding how to deal with lead-acid batteries…

It has been my successful practice during decades of wet-cell/lead-acid battery use: Don’t let deep cell batts get more than 50% discharged before full recharge (it’s OK to fully recharge at any time before that 50% level is reached). Immediately fully recharge starter batts after each use. As long as left in a fully charged state with electrolyte at correct level and isolated for no draw-down occurring… It’s OK to let batts of either type stand unattended (i.e. no charging at all) for up to six months. Climate conditions can have effect on several items regarding charging/using/letting-stand for any batts.

Credit:Following excerpt is from website: “Battery University”

http://batteryuniversity.com/learn/article/charging_the_lead_acid_battery

Watering

Watering is the single most important step in maintaining a flooded lead acid battery, a requirement that is all to often neglected. The frequency of watering depends on usage, charge method and operating temperature. A new battery should be checked every few weeks to determine the watering requirement. This prevents the electrolyte from falling below the plates. Avoid exposed plates at all times, as this will sustain damage, leading to reduced capacity and lower performance.
Exposed plates will sustain damage, leading to reduced capacity and lower performance. If the plates are exposed, immediately fill the battery with distilled or de-ionized water to cover the plates, and then apply a charge. Do not fill to the correct level before charging as this could cause an overflow during charging. Always top up to the desired level after charging. Never add electrolyte as this upsets the specific gravity and induces rapid corrosion. Watering systems eliminate low electrolyte levels by automatically adding the right amount of water.
Simple Guidelines for Charging Lead Acid Batteries

• Charge in a well-ventilated area. Hydrogen gas generated during charging is explosive. Please see Health Concerns with Batteries.
  
• Choose the appropriate charge program for flooded, gel and AGM batteries. Check manufacturer’s specifications on recommended voltage thresholds.
  
• Charge lead acid batteries after each use to prevent sulfation. Do not store on low charge.
  
• The plates of flooded batteries must always be fully submerged in electrolyte. Fill battery with distilled or de-ionized water to cover the plates if low. Tap water may be acceptable in some regions. Never add electrolyte.
  
• Fill water level to designated level after charging. Overfilling when the battery is empty can cause acid spillage.
  
• Formation of gas bubbles in a flooded lead acid indicates that the battery is reaching full state-of-charge (hydrogen on negative plate and oxygen on positive plate).
  
• Reduce float charge if the ambient temperature is higher than 29°C (85°F).
  
• Do not allow a lead acid to freeze. An empty battery freezes sooner than one that is fully charged. Never charge a frozen battery.
  
• Do not charge at temperatures above 49°C (120°F).