Low Battery Cutoff And CAN'T Understand Why

[Monaco2000]

Monaco diplomat 2000. I am a new owner. Kinda confused.

House batteries were 9 years old and low battery cutout kept knocking off our inverter.

We are parked at a great park with 50 amp power. We have a surge protector.

Decided to buy brand new Trojans 4 x 6 volt batteries proper amperage.

After having spent all this money we thought we had found problem(old batteries).....they were old so we are glad we replaced them.

We went in the bus and it was charging at only 12.1 volts with the new batteries but we thought we were fixed. Put on TV and then electric heater ( that is all as we had switched fridge to propane after the low battery kept going out so we left it on propane till tomorrow).....now with just TV on and a couple of lights we are at 11.3 volts.....won't hold over 12v....

Our inverter is a Magnum energy 2012 as many of you have and brand new house batteries.....now it won't charge batteries again and is still causing low battery knockouts.....

I am going nuts. What can I do except pack up and go sit at camping world and get a technician to look at whole system.....maybe a short in the inverter??

What am I missing?

Thanks for any of your help

[shields]

Greetings, and welcome to the FMCA forum.

Your old batteries were not taking or holding a charge. Now you've replaced the batteries and are having the same troubles. Here are a few ideas.

1. Are you certain the campground electricity is sound? Maybe you are not actually getting adequate power from the 50 amp pedestal connection. If you can SAFELY test the two legs of the 50 amp campground input, that's a good place to start. If you are not sure how to check the pedestal power, please STOP. There are articles here and in the FMCA magazine that explain the proper and safe procedures.

2. Assuming adequate input power, your inverter/charger should bring your batteries up to full charge in due time. A next step would be to check the charging voltage at the battery terminals. Your manual should include data on the charging voltages. Let's see if the charger is putting out the proper voltage to get the batteries charged. 12.1 volts is not adequate. Are you sure that was the charging voltage or could it have been the existing battery output voltage?

3. Your charger probably has different settings for different types of batteries, or even different temperatures. This is sometimes accomplished by setting tiny dip switches on the inverter/charger or with a control panel program selector. You might check and see if the switches or program are set to charge the type of batteries you installed.

4. If all else checks our, it is always possible that one or more of the new batteries are defective. That, however, seems unlikely.

Let us know what you find on items 1 through 3 and we'll try to help you narrow down the trouble.

Good luck,

Tim

[wolfe10]

Tim gave you a good start.

While on shore power, your inverter should not be powering your 120 VAC circuits. The shore power should be "passed through" the inverter and, when the inverter/charger sees 120 VAC from shore power or generator, the charger section also kicks in.

So, if the inverter is, indeed "inverting" to supply 120 VAC, either the inverter is not receiving 120 VAC from your coach main breaker panel, or you have a problem with the inverter/charger. Turn off and back on the inverter breaker(s) on your 120 VAC main breaker panel. If that doesn't do it, you will need someone safe working around 120 VAC to check for 120 VAC at the inverter and/or the inverter itself.

[Monaco2000]

Thanks so much for your warm greetings.

We will try your suggestions but are not real sure on how to do 1 and 2, Tim so we will have to get a technician I guess.

I have checked the settings in display unit in the bus and they seem to be all on default. The battery type is set to flooded which seems right for a lead acid battery.

Will try to on off with panel as well Brett, but not confident this will do much. I do appreciate your immediate input.

Don't really know what else to do on a weekend in Florida

The voltage is sinking as well. Now it's 11.2. Brand new batteries. Weird.

I guess I may have a bad battery but they were pulled right off the pile and full to right levels. Checked them before installing.

Can I bypass the inverter to run the bus? I have read many members saying they don't use their inverter but when I turn inverter off I get NO juice to anything?

Thanks and keep comments coming. I have to get this fixed or I will have to go see a dealer on Monday which could get pricey.

Claude and Sue in Naples Florida

[wolfe10]

If you can not troubleshoot 120 VAC to the inverter/charger (so it can charge the batteries) there are two "Plan B's):

1. Start coach engine (even if you have to use jumper cables from your toad to do it) and let the alternator charge the batteries-- use high idle.

2. Use a stand alone battery charger directly on the house batteries.

Brett

[Monaco2000]

Thanks all.....we figured it out with all the minds at the park. And thanks to Brett for his suggestion.

When I put in the 4 new Trojans I mistakenly put one upside down. I caught the error at the time but never noticed that it knocked the breaker off....we checked all the main breakers and one was showing red. The batteries were completely discharged by then so the inverter worked hard to get us back up but now is charging at 13.5 V.

New problem though is my surge protector is flashing red as of last night. Says one line is low. weird because he came with a gage and both lines out of power post were showing 122V or so when we were trying to find the charging problem (maintenance man at park came by).

So now I wonder why suddenly my Surge Protector is flashing red.....

Will get maintenance man to come by again and recheck. Hopefully I am not hurting the new batteries now......

Will update....