Batteries / Generator / Inverter

I have multiple problems with a 1995 Marathon XL # 355.
For months the batteries seem to be very low, and or not hold a charge for a long time (A couple of hours at most). We do not dry camp much so that was not a problem it gave us a chance to exercise the generator.

When all of the mechanical problems below are resolved I plan on replacing the batteries.

I just completed replacing the entire generator excluding the diesel engine because the sealed bearing went out of it on the generator end with 2000 hours showing on the hour meter $35.00 bearing $3000.00 generator.
To check the bearing you need to remove all of the end pieces on the generator, Outer casing, Diode Plate, Exciter Stator, Exciter Rotor, etc. in A very tight working area.
That’s labor intense considering you would likely not find a problem at the correct time; my experience is that seal bearings tend to hide their problems until it is too late.

This got my attention the other morning when I entered the coach the refrigerator off audible alarm was going off and the dash light was blinking saying Refrigerator off.
The refrigerator will start and run for about 45 seconds then shuts down for the same amount of time, plus or minus, on off on off constantly.
The inverter #1 changes its light pattern also in the same pattern with the refrigerator.
If I turn the refrigerator off from the control inside of the refrigerator the inside refrigerator lights and inverter #1 will continue to fluctuate on off.
I have turned off all circuit breakers (Mains & branch) in the bedroom and the refrigerator and inverter #1 continue to fluctuate.
I cannot find a circuit breaker or any other device to turn the refrigerator off the only way I have found to turn the refrigerator off is to put the #1 inverter switch in the off position on the dashboard.
The # 2 inverter works fine, and the coach is always connected to outside power except when we are traveling.

The above mention problems are small considering the health issues that I had in Austin thankfully they have not returned since then, I will see the Doctor tomorrow for a continuing checkup, I am looking forward to POG 11. Also I would like to again thank the POG Doctor for his advice in Austin.

Don,

Good news about your health. Post more often.

Bear in mind I have no clue about how a Marathon is set up electrically, but I can tell you that unless your batteries are known to be good they can create strange problems and drive you crazy. You don't indicate their age, but at 5 years you have gotten just about all you are going to get from them in normal use. That lifespan is shortened if they have been abused by allowing them to drop to a very low voltage level or charging them to voltages other than those the battery manufacturer recommends.

All it takes is one bad battery in a set to mess up a set so based on the problems you describe my first recommmendation is to separate the batteries and test them individually. If any are found bad, replace the set. Once you have a good set of batteries you can determin if the issue with the inverters continues or if it was related to the batteries.

On my coach both inverters are simultaneously acting as battery chargers with one being the dominant one. My batteries are set up as a single set, so even if one inverter fails to charge the second inverter continues to function as a charger. Periodically I will test each to verify both inverters are functioning properly. I do that by turning one inverter off and verifying the remaining one functions as a charger. I also verify when I am on shore power or generator that they are passing current through to the inverter circuits (refrigerator, outlets, TV, aux. compressor, etc.), and I also verify they are inverting by checking for power through the inverters when no shore or generator power is available.

But the first place to start is with batteries. I had an inverter act crazy a couple of years back and as a result I ended up starting with the batteries and verifying every cable connection, and then every ground connection. It is not as simple as it sounds because all connections on the positive side went through not only battery post connections, but master circuit breakers and master switches. Cleaning and retightening all connections solved the problem although I never could identify exactly where the problem was.

If you do not have the operator's manual for your inverter and remote panel I suggest you go on line and download a copy. You need to understand what the panel is telling you and you need to know your remote panel is programmed properly for your type of house batteries. Maybe a Marathon expert can help with more specific advice.

Don,

I am the owner of a 1995 Prevost, Country Coach. During the first year of ownership, I experienced issues of short battery life and inverter reliability issues. On a trip, an inverter faulted (the inverter that powers the refrigerator) and I had to do some innovative wiring each time while underway to feed all the circuits from one inverter. When plugged in to shore power, all was OK.

With battery low life issues and an inverter problem (the inverter transfer relay had arced and a contact needed cleaning), I decided to upgrade the inverter system and replace all batteries with Lifelines. Since, this was done, the inverters and battery system operate as a "background", as they should.

I replaced my original inverters with Magna Energy, pure sine wave inverters. These inverters operate on a data network communicating to the front panels and the auto generator starting components.

I purchased a battery checking device (I can't remember the model number) that verified that of my 8 each, 8D size batteries, four batteries were dead, two were less than 20 percent available and only two were were above 50 capacity. So my battery bank was essentially dead. As a sidebar, the battery checker is a "non destructive" type that checks individual cells, without placing a large load on the battery. I will get the model number for you if needed.

I made up a post concerning this, but I am unable to find it in a search. I do not have much luck with searches on the POG forum.

If any other members can find the post, perhaps it will help offer some information for Don.

Hector

Hi Don! Glad you are doing better. I have nothing to input for the coach's batteries, but am more interested in yours! ;)

Our bus, sitting contentedly in the bus barn is constantly being powered and batteries kept charged by the inverters. I was lulled into thinking all was well until we had a utility power failure last week. When I checked the coach in the morning I found the batteries read a pitiful 7.8 volts. Seems that they can fail even when being charged. A panic call to Trukster and he determined from the code stamp that they were 8 years old so they didn't owe me a thing.

Tom to the rescue. His price on Lifeline 8D's is at least a hundred bucks cheaper than anyone on the internet. He ordered them for me last Thursday and they arrived today. Many thanks Tom!