[Guy]

Today we woke up to the dreaded sulpher smell of a hot battery. one of our house batteries was at 195 degrees , the other at 100 with the ambient temp being 85 degrees. I had recently checked water level and cleaned connections and all was good at that time.I used the battery disconect switch for the house batteries, and am assuming the offender will cool down. I still have 12 volt interior lights water pump . We are on a 50 amp site here in Virginia.  The house batteries are at least 6 years old, and I should have converted to agm last fall , when a good friend in Arizona offered to hook me up with his battery people. Other than a shorted out battery could I have other issues, or just head to Orileys and order the agm's ?

[Richard]

Go get batteries.

In the mean time, take the offending battery completely out of the circuit and use the remaining batteries for 12V power.

I would not mix a new battery in with six year old batteries.

To check your charging system, disconnect the offender as previously stated. Do it such a way to maintain 12V continuity. Turn the system back on, and monitor the charger.

What charger and inverter/charger do you have?

[Guy]

Thank you Richard. Tom generously offered to help last fall.  What do they say about hindsight? What is interesting is that both of us have been smelling propane,  not sulfur for several days. Yesterday our Amazon propane sniffer arrived and of course found nothing. Both odors are so very distinct.  Interesting that we both thought sulfur was propane.

[Guy]

12 volt converter is a Progressive Dynamics 70 amp 13.6 v dc PD 9270. The converter began rapidly cycling on and off after the discoverieng the ist overheated battery. The inverter is a Xantrax 3000 Plus . I took the hot 12 v coach battery out of the circuit. Now one of the engine batteries is turned hot in the past 2 hours, very hot, 180 degrees. Coach and engine batteries are not merged. I have turned off the converter until we can sort this out.

[Richard]

Someone with that era experience will have to comment on which the converter or the inverter is charging your batteries.

If it is the converter, they are known as battery boilers for a reason.

The reason that propane and sulfur smell so similar is that propane is dosed with a chemical family known as mercaptans to make it obviously smellable. Mercaptans are organosulfides, meaning they have a petroleum backbone with a sulfur attached. And that’s your chemistry lesson for today.

And if the batteries are not merged, something is very amiss in the engine battery overheating. Your best friend here is your voltmeter. Take readings at all batteries and merge solenoid with the converter OFF, then turn it on and take the same readings again. That will tell you two things. What voltage the converter is producing, and what components are seeing that voltage.

I know you have Tom’s info. Mine is 817 223 2056

[Guy]

Richard, the Cole Hersee transfer solenoid was "welded" in a merge position. I have had identical voltage readings on the dash for both engine and house batteries for some time . Now I know why. I had two spare solenoids. Now I am down to one. If we were boondockers, we would have discovered this I am sure . After turning off the converter, the "propane" smell from the past 3 weeks is gone. Magic !

Thank you for the chemistry lesson. It is appreciated. We are off today to order all (4) new agm batteries. It is a 110 mile round trip across the Chesapeake Bay Bridge to the nearest O'rileys, so I may end up doing business with the local Advance Auto Parts. Yesterday we ordered a new converter from Amazon.

Update.....Went to Auto Zone today. 8D agm batteries aren't available according to them. Off to Orileys tomorrow to get them ordered

[bestgenman]

It may be too late now but some converters offer a “float charge” option.   My feeling is it is a desired feature since it keeps the current flow down as the voltage level rises.

[Guy]

I ordered a Progressive Dynamics (PD9270V) having "iCharge Wizzard" Don't know how it will fare on tapering charge to meet battery condition, but the marketing department did a nice job on the words. They list this one for wet cell and AGM, and had another for lithium ion. I think the coach was set up with this along with a stand alone inverter, Xantrax Power 3000 plus. If I find a better maintainer in the future, I will change in a heartbeat. These are just a fraction of the cost of replacing batteries.

[ROBERT BLAIR]

The battleborn 100 amp hour batteries are far superior to lead acid or AGM.
When your AGMs are done research lithium iron.
10 year warrantee
No damage from full 100% discharge.
No fire risk
3000 to 5000 charging cycles
31 pounds vs 167 for AGM
Great factory support for design and install
American manuf in reno nev
I use AGM for starters and keep them on a genius 24v charger full time.

IMHO It is silly to install anything but Battleborn 100 ah for house batteries.
I have 12 in coach 267.
Safer and cheaper in the long run.

[Richard]

Guy,

I went to the Progressive website, and I think you will be just fine with charge wizard. It looked to be the standard three stage charge profile that you would find in a Magnum, Xantrex, or Outback inverter/charger.

Keep an eye on your engine batteries. Unfortunately the combined charger malfunction and the welded solenoid exposed your engine batteries to the same over charging. The real issue is if the engine batts are cooked, then you expose your alternator to bad batteries. Not good for the alternator. I am not saying your engine batteries are bad. Just saying keep an eye on them and the charging amps from your alternator.