Stinky Batterie(s)

[Jduncan99217]

We have a 2000 2800SCR that we moor fulltime and my wife lives on it for the summer.
During the week the boat doesn't get moved and is hooked to shore power 24/7. Last week we noticed a rotten egg smell coming from the engine compartment and discovered that one of the batteries was making a crackling sound.
So, we switched our battery selector to the other battery and the smell and crackling noise left.
Battery #1 was new at the start of this season, and battery #2 was new mid-way through last season. I replaced the battery charger about this time last year also to a new electronic two bank charger.
One of my questions is, where should I keep the battery selector while moored? #1, #2 or both?
The next question is, what would cause the battery to smell?

[MoonRiver]

Jim,
I keep my selector switch on "both". And the rotten egg smell typically comes from your hot water tank. I'm not sure why but marine hot tanks can get a rotten egg smell for some reason. I noticed ours smelling a bit a couple of weeks ago. We don't keep the hot water tank "on" all the time, only for short time to wash dishes.

Doug (MoonRiver)

[mmwjr]

I would not have the selector on both but only on the house battery which should be number 2. What type of batteries do you have ; flooded, AMG,...?

I would not leave the charger on full time however it should regulate back if the battery doesn’t need charging. Something is wrong with your setup.

If the charger the correct type for the battery you have? That smell is from overcharging. Interesting my son in law just had a similar issue with his car, rotten egg smell and would not start. The seal around the positive terminal failed and the acid corroded away the cable clamp.

[Ken Kwasniak]

My dock neighbor had that rotten egg smell from his battery, next thing he knew it blewup. Get it checked out right away.

[Gugi47]

Originally Posted by Jduncan99217

We have a 2000 2800SCR that we moor fulltime and my wife lives on it for the summer.
During the week the boat doesn't get moved and is hooked to shore power 24/7. Last week we noticed a rotten egg smell coming from the engine compartment and discovered that one of the batteries was making a crackling sound.
So, we switched our battery selector to the other battery and the smell and crackling noise left.
Battery #1 was new at the start of this season, and battery #2 was new mid-way through last season. I replaced the battery charger about this time last year also to a new electronic two bank charger.
One of my questions is, where should I keep the battery selector while moored? #1, #2 or both?
The next question is, what would cause the battery to smell?

You need to buy one Smart marine battery charger- analyzer. They are not cheap but worth every penny. You never have a hot or overcharge battery again:

https://www.ebay.com/itm/Newmar-PT-4...AAAOSwWE9bOfyc

https://www.ebay.com/itm/Battery-Cha...kAAOSwYmZXKTSA

But they are so many others. I got my from West Marina for $300 and is good for 30A.

[jparsons121]

Battery definitely went bad. Charger could have boiled off the water and the plates were damaged. Smart chargers should regulate the charging based on what the battery needs.
I run with a 3 bank Promariner and its on all the time with no issues. Chargers also run directly to the batteries, so selector switch only manages where the load goes. Since I run the same battery types for both bank 1 and bank 2, I alternate between them. When on shore power its once a week I switch. When on the hook I alternate daily, Odd dates I use bank 1, even dates bank 2. Both is only used when I need the extra cranking power.

I second the comment to check the settings on the new charger. Flooded lead acid and AGM are very different profiles.

John

[Gugi47]

Here is the page from West Marina:

https://www.westmarine.com/mounted-battery-chargers

and here is the one I got:

https://www.westmarine.com/buy/proma...67?recordNum=8

But now are $369.99.... wow. Was $299.99 when I got it.
But if you have 2 batteries only. You should be good with 20A charger. Me, personally, I always go overboard and buy bigger battery and charger. I have group, class 27, 1050 cca battery.

[shrew]

The sound you're hearing is the battery boiling. The smell is the battery off-gassing because it's boiling. If these are flooded batteries, then you would need to be regularly checking the fluid levels and ensuring the batteries are getting topped off with distilled water.

The boiling and off-gassing could be the result of an empty battery or a bad battery charger. A good quality 'smart' charger should not boil batteries.

As for the battery selector. One battery should be dedicated as a Starting battery. The other battery dedicated as a House battery. I would have a much larger house battery than a starting battery. Most commonly Selector Position 1=Start; 2=House.

1) What is the size and type of Battery 1?

2) What is the size and type of Battery 2?

3) What is the make and model of your charger?

NOTE: AGM batteries don't off-gas. This is a condition more common with flooded batteries.

[rwc]

Wouldn't the starting battery also usually be designed to deliver high cold cranking amps, while the house is designed for steady slow discharge?

I'm not sure what that means in terms of battery design or chemistry (if anything), but I just replaced mine and the starting battery was designated "marine start" and the other was designated "RV". One has a higher amp hour rating and the other has a higher CCA rating.

[jparsons121]

Spot on rwc. There are different types for the types of uses/loads.
Most boats don't have a true House vs Starting bank.
What they have is selector switching to direct the house/starting load to a particular battery.

On my 3000, there are two batteries. Both get used for both house and starting. If one were to trace the wiring to the Both-1-2-Off switches, you will see how the design is flawed. I've compromised and run dual purpose batteries for each. They have sufficient (not the highest) CCA for starting, but heavier plates for a better aH rating for the long discharge on the house loads. Not the best at either, but I can start OK and won't burn up a true starting battery by deep discharging when used for the house loads.

Plan has been to add a 3rd bank for pure house use. Either true deep cycle 12v or 6v golf carts batteries (in series) along with the required switching to allow the loads to be directed to any bank or combined if needed in an emergency.

[Gugi47]

Originally Posted by jparsons121

Spot on rwc. There are different types for the types of uses/loads.
Most boats don't have a true House vs Starting bank.
What they have is selector switching to direct the house/starting load to a particular battery.

On my 3000, there are two batteries. Both get used for both house and starting. If one were to trace the wiring to the Both-1-2-Off switches, you will see how the design is flawed. I've compromised and run dual purpose batteries for each. They have sufficient (not the highest) CCA for starting, but heavier plates for a better aH rating for the long discharge on the house loads. Not the best at either, but I can start OK and won't burn up a true starting battery by deep discharging when used for the house loads.

Plan has been to add a 3rd bank for pure house use. Either true deep cycle 12v or 6v golf carts batteries (in series) along with the required switching to allow the loads to be directed to any bank or combined if needed in an emergency.

Deep cycle high CCA battery is what you need. Here:
https://www.ebay.com/itm/VMAX-XCA31-...nd!17601!US!-1

You can find them in grupe 27 to, with 1000 CCA. That's what I have.

[dannyrayz]

How are you storing your batteries in the off-season? Leaving them in the boat and just disconnecting them? Taking them home and Trickle-charging inside?

[jrsick]

Originally Posted by MoonRiver

Jim,
I keep my selector switch on "both". And the rotten egg smell typically comes from your hot water tank. I'm not sure why but marine hot tanks can get a rotten egg smell for some reason. I noticed ours smelling a bit a couple of weeks ago. We don't keep the hot water tank "on" all the time, only for short time to wash dishes.

Doug (MoonRiver)

Doug, you may want to check the anode in you water tank. When the anode is depleted you will get the rotten egg smell.

[Gugi47]

Originally Posted by dannyrayz

How are you storing your batteries in the off-season? Leaving them in the boat and just disconnecting them? Taking them home and Trickle-charging inside?

You take the positive cable off and just leaving them on the boat.
48 hours before you take the boat for a spen charge the battery for 8 hours. Again, I suggest the smart charger.
The old chargers they become useless for the new technology.

[Jduncan99217]

I would like to thank each of you for your advise.

Here is what I have found:

1. Both batteries are house and starting batteries by the way they are wired

2. Both batteries are marine starting batteries (which is the problem)

3. If the selector is set on "both" we don't have any smell

4. I am going to get the proper batteries for next season

Jim

[Jduncan99217]

Last year I left them in the boat on the charger...this year they are coming in the house and going on a trickle charger.