RV Converter Question

Q. I live in a large 5th wheel full time and I am plugged in at all times. I heard the battery charger kicking in from time to time and the humming of the converter. Do I have to have the converter on all the time? Is it on only to charge the batteries? The manuals are the pits and I am really trying to know all about converters. The more questions I ask from different sources the more answers I get. I read your web site you do explain well. Thank you.

Mark Says: The converter in your RV basically does two jobs.
1) When you are plugged into electricity it converts a portion of the 120 volts coming into the RV down to 12 volts so all of the 12 volt devices like overhead lights and fan motors will operate without draining the RV battery.
2) It has a battery charger built in the converter to keep the RV battery charged (topped off).

The noise you are hearing is most likely the fan on the converter. The converter gets warm when it is on so the manufacturer adds a fan to help keep it cool. Some are very noisy.
You do need the converter on when you are plugged in. If the converter wasn't on, or wasn't operating properly you would run the RV battery down because you are using the 12 volt appliances and devices.

Some older RV converters charge the batteries at a constant rate and will continue to charge the batteries when they are fully charged. This can result in the battery or batteries losing water, so battery maintenance and inspections are important when you have the RV plugged in for long periods of time. Newer converters have 3 stage chargers that know when the battery is fully charged and at that point in time only provide a float charge (less charge) to prevent overcharging conditions.

Read this article I wrote on converters that might help explain it in more detail. http://www.rvuniversity.com/article.php/20080107175732307

17 comments:

  1. Mr Polk,

    I hope that you are checking comments... My converter is buzzing quite loudly... it has been doing so for some time. I was having the fridge serviced at Campers World in New Braunfels, Texas, and they said they would replace the converter using my extended warrantee... however they did not do so, despite the claim. Is he converter actually going bad? It seems to be getting louder and louder every day, though that may just be in my head. Regardless, it doesn't sound "normal"... It's not the fan, I'm sure of that. Any suggestions would be great. thanks!

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  2. This comment has been removed by a blog administrator.

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  3. If the batteries are older, say 4 years, but have been maintained well-d. water added when needed- is there still a chance they might not hold a charge. When I'm on shore power and the breaker kicks for some reason, the Inverter Interface panel shows the battery as discharged. That's if the shore power is off only for a minute or so. Doesn't seem right somehow. Thanks,
    Mel

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  4. Patrick, I have heard converters that make alot of noise but still work well. As you mentioned the noise is usually the fan cooling the converter down, but I have heard the buzzing noise as well. I'm not sure what to tell you. If it does in fact continue to get louder and louder you should have it looked at.

    Mark

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  5. Mel,
    The length of time batteries hold a charge will shorten over time and eventually they won't be able to hold a charge anymore. There are numerous reasons for this but probably the most common reason is that the plates get so much sulfation built up that the battery can no longer hold a charge.

    You can have the battery checked with a hydrometer, at a battery shop, to see the actual condition of each cell.

    Mark

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  6. As an Electrician 8 years now, I can tell you all that Generally before a Transformer goes dead it will buzz louder and louder.. it is usually caused by the coating on the windings has gotten too hot from it being overloaded and then the Coils will short. Sometimes they go out with a Bang, sometimes just a poof of smoke. either way when it is your Converter for your power in your camper.. Not good.. The older they are the more likely they are to have been overloaded at some point in time.. and the ore likely the coating is to fail as a result of their age.

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  7. The explanation was quite concise, and the process that explains how converters function was informative as well; you even offered simple troubleshooting methods. However, I would like to know your techniques to prolong the life of my RV’s battery. And, in your opinion, how often should you have it checked?

    Liza Pilon

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    Replies
    1. HI Liza,
      I have several articles and videos on RV Batteries that will help you understand battery life more in depth:
      http://rveducation101.wordpress.com/2010/11/03/rv-batteries/


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  8. Can I completely remove power converter and just use my 110. My camper never moves because I live in it. I hate hearing all the buzzing from converter.

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    1. I want to know this also. My converter is dead and removed. I only need 110v power and I'm scared to plug in.

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  9. Hi there.

    Well I had a nice long comment all typed up and it deleted it :( I'll try again.

    We have a small 1996 jayco pop up, 1007. We currently do not have a battery in the box and strictly use serviced sites. The trailer has a fridge, 2 lights and 3 receptacles. Generally we have a small fan, a small heater and a night light plugged In. Last year we bought a Keurig coffee maker. When I plug the in to the outside receptacle we blow the breaker in the trailer. I started running a second power supply (extension cord) from the pole for the coffee maker. I am using a splitter at the single 30amp plug supplied. Now we don't blow breakers, we just get a loud buzz from the inverter whenever it's on. What could cause this, a drop in voltage or amps at the pole? Do I need to be concerned? After I have had my morning cup-of-life the buzzing is gone.

    I will really appreciate any help/info I get.

    Thanks,
    Dan R.

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  10. I have a new 2016 Montana 3791RD that I believe is having inverter issues. It was delivered to my permanent site (50amp power) 2 wks ago and noticed the inverter wasn't running when I plugged into my 50 amp station.

    Powered inverter off and removed the fuse. Re-inserted the fuse and the unit still would not run. Neighbor who has same 5th wheel came over and stated his 5th wheel inverter runs all the time. Let me borrow his fuse and my unit ran fine.

    Switched my fuse back in later and unit ran fine. Ordered new fuses and put installed it. Unit ran fine then shut down on its own. Unit does not run continuously and appears to shut itself down.

    Runs fine when I power it down and re-insert the fuse.

    Is my inverter defective or faulty? Should it run all the time or be powered on?

    Steve

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    1. Hello Stephen,

      If I understand correctly the RV is on a site that has 50 Amp electrical service. When the RV is plugged into electricity there is no need for an inverter. The inverter changes 12-volt DC (battery) power to 120-volt AC power so you can use 120-volt devices when you don't have electricity. When you do have electricity there is a converter that changes 120-volt AC power to 12-volt DC power so the 12-volt devices in the RV work. I don't see any reason to use or need the inverter when you are plugged into electricity.
      Mark Polk

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    2. Hello Stephen,

      If I understand correctly the RV is on a site that has 50 Amp electrical service. When the RV is plugged into electricity there is no need for an inverter. The inverter changes 12-volt DC (battery) power to 120-volt AC power so you can use 120-volt devices when you don't have electricity. When you do have electricity there is a converter that changes 120-volt AC power to 12-volt DC power so the 12-volt devices in the RV work. I don't see any reason to use or need the inverter when you are plugged into electricity.
      Mark Polk

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  11. I live fulltime in my 2004 Forest River Wildcat. We do not have batteries or a generator. We are plugged into parks service.
    What I wan
    t to know is everyone is telling me that I must have batteries in my rig. So I go looking all over for a battery. There is no batteries in my rig.
    So is that ok to not have batteries? We recently had a wire on my converter overload (I think) and about 6 inches of the coating on the positive wire that is directly behind the converter panel melted.
    Do I need to replace my converter, buy a battery, and replace that wire?
    New to this.
    Thank you.

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    Replies
    1. If the RV is plugged into electricity you do not need a battery. The battery is used to operate 12 volt devices when you are not plugged into electricity. You also need a battery to activate the trailer breakaway switch, but that is only while towing.

      As for the converter problem the first thing you need to do is find out what caused the wire to get hot and have it repaired. I would also recommend using a product like a Surge Guard surge protector at the electric pedestal when you plug the RV in. It will automatically shut the power going to the RV off in the event of high or low voltage or an improperly wired electric source. To watch a video on this go here.
      https://youtu.be/KB0_isIeZEM

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  12. Receptacles dont work in the camper bist the lights fridge microwave and ac do. There is a loud hum coming from the power box what do i do

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