Battery 6V Boiling

[jeffmfi]

  After traveling for 3 weeks, staying at 3 RV sites we arrived home 2 days ago. This morning I went outside and smelled a awful smell. The odor was coming from my RV battery storage area. I opened it and found one of my two 6V house batteries was boiling, making a noise and venting out two of the cap tops forming puddles on top. I unplugged the RV shore line, they continued boiling. I checked the temperature, the battery was 160 degrees  and climbed to 170. I took the garden house and cooled the battery and the boiling stopped. the two batteries dropped from 13.5 to 11.5. The battery is 8 mts. old. After it cooled I added 1 quart of distilled water. The battery is still hotter than the other two. I did check the level before traveling.

Any idea why this happened?  What should I have checked ? I have an appointment with Interstate in the morning.

[bm02tj]

you have a bad cell 

replace it 

[richard5933]

If this was my rig I'd also be checking to see if the battery charging system was working properly. If the battery is only 8 months old it sounds like you've had problems recently (or the previous owner did) resulting in a new battery. Maybe this has been an ongoing issue, something like a charger that occasionally over charges the batteries and doesn't know when to stop charging. This could be caused by a long list of problems, including a charger that charges at too high a voltage, bad connections, loose wires, etc. Do you have multi-meter you can use to check the charging voltage?

It would be helpful for us trying to help you if you could add some details about your RV to your profile, then members with the same or similar rigs could use their experience to help you better. There are so many variants of how RV battery systems are installed that it's impossible to do anything other than guess just knowing that you had a battery boil over.

[dickandlois]

jeffmfi,  Welcome to the FMCA Forum !

The smell is Hydrogen Sulfide / the rotten egg smell.  FYI it is best for your own safety, when you smell or notice the battery bowling  - To disconnect the coach from shore power , let it set for 10 min. then hose things down real well.

  As posted you have a bad battery, that needs to be replaced. The battery should have lasted longer then 8 months though. One Does fail from time to time, but have the charging systems tested - both the Charger when connected to shore power and the Engine Alternator. 

       The Key also could be the way your charger is setup in the charging menu, charging current to high for the battery rating.   This  is where more information is helpful.

So if you could post the Make, Model and year of the coach along with information on the charger / inverter installed in the coach, you help the members offer better information.

Then when things settle down add the information , at the bottom of the page like Richard has done, and if you need some help doing it just ask and someone will help you with that also.

Rich.

[wolfe10]

jeffmfi,

Yes, welcome to the FMCA Forum.

Two causes of batteries boiling.  As already posted, the most common is for a cell to go bad.  When that happens to a 6VDC battery, it, in reality becomes a 4VDC battery.  So, a charger, doing exactly what it should (in terms of charging voltage) will WAY over-charge those remaining good cells.

Another cause is that a "stupid" charger or smart charger improperly programmed will charge at too high a voltage.

[jeffmfi]

Thank you for your help. I have a1997 Monaco Dynasty with a Freedom 20 Inverter/converter. I do have a Multi-meter and checked it at the batteries and it has been around 13:50. I replaced all (3) of the batteries two years ago because they weren't holding a charge for a long time when it was unplugged. 8 months ago one would not charge and had a dead cell, had to buy a new one. I replaced the 2 house batteries with the Interstate SRM-4D and the engine  1 Interstate 8D-XHD. these are the batteries the unit came with new so I stayed with the same ones since they were available. I do think it is a charging issue and I'm a part time Rver. What would be the best way and or who to check this problem out.

[wolfe10]

With wet cell batteries, most accurate is to fully charge and then test with a HYDROMETER-- under $10 at any auto parts house.

Have you programmed your Freedom 20?

[jeffmfi]

Hydrometer sounds good, No, how do you program my freedom 20 and how often should I do that?

[wolfe10]

Pull out your Freedom Inverter manual or look on-line.

It is a smart charger, but you need to tell it what you need.

You will tell it:

1. Battery bank size (in amp-hrs)

2. Battery technology (wet cell, AGM, gel)

3. You will tell it ambient temperature range (unless you have the optional battery temperature probe). Correct charging voltage in hot temperature is LOWER than when it is cold out.  So, if no temperature probe, you will change this setting seasonally.

 

Depending on age of coach,  this programming is accomplished by (from earliest models to new): Dip switches on inverter/charger OR dip switches on back of remote panel OR programming from front of remote panel.

[rsbilledwards]

My Freedom in the 2001 Safari Zanzibar was not so smart and when one called Xantrex getting info was like pulling chickens teeth. Current Magnum inverters I think a better choice as everything can be changed easily. It has a better charging cycle I think...

[jeffmfi]

Thank you. I was in cooler temperatures for my travels until I  returned to Arizona, over 100 every day. Hard on batteries.

[obedb]

If only one house battery was causing the trouble, how could the charger be the culprit?

[wolfe10]

Byron,

Agree the charger may not be the root cause.  But, it can be if voltage too high and lack of maintenance.

Here is how it progresses:  Charger overcharges/voltage too high.  Batteries boil.  Water level not maintained. Hottest cell boils dry first.  Once dry, it fails, making a 6 VDC battery a 4 VDC battery/12 VDC battery a 10 VDC battery.  Charging a 10 VDC battery (one dead cell, whether in two 6 VDC batteries in series or a 12 VDC battery) at 13+ VDC is WAY OVER-CHARGING IT. Battery death is imminent.

[jeffmfi]

I'm back from Interstate, the battery was two years old that boiled. It had one dead cell at the positive post. The cell always had water even after it boiled, one cell away both directions were lower due to venting. I did add one quart of water to the total battery, no plates were showing. They told me I only needed one new battery, bought one, plus and Multi-Battery Isolator, mine showed heat damage and a hydrometer. 

[hermanmullins]

Thanks for the update.

Herman

[bm02tj]

Get a 6 volt charger and and bring the batteries to equal charge before putting them in series 

 

[desertdeals69]

18 hours ago, jeffmfi said:

I'm back from Interstate, the battery was two years old that boiled. It had one dead cell at the positive post. The cell always had water even after it boiled, one cell away both directions were lower due to venting. I did add one quart of water to the total battery, no plates were showing. They told me I only needed one new battery, bought one, plus and Multi-Battery Isolator, mine showed heat damage and a hydrometer. 

Changing one battery in a group will work but I always change all of them because I match mfg, dates, models so they are evenly matched.  Seem to work better.

[wildebill308]

2 hours ago, desertdeals69 said:

Changing one battery in a group will work but I always change all of them because I match mfg, dates, models so they are evenly matched.  Seem to work better.

That is a good idea if you are putting a new replacement in a existing bank I would make sure it was charged before adding it to the bank. 

 I charged my new 6 Volt batteries before I installed them. I had the time and also topped them up with water. The 4 new EGC2 batteries took over 1/2 gal of distilled water.  

Bill