Is my converter necessary when hooked up to shore power?

[timotheius]

Hi everyone, I'm new to the forum and brand new to campers. I just purchased a 2009 Salem 312bhbs. I don't ever intend to use it unless its hooked up to shore power. However, so far, it seems that the converter runs non-stop when I'm hooked up to shore power. I hate the noise of the converter and would like to find a way to shut this down. I find the constant hum of the fan to be very annoying. However, whenever I flip the breaker switch for the converter to "off", every light in my camper turns off. Are all the overhead lights DC power only? Does this mean that none of the overhead lights work on AC power, and if I want light in the camper I have to have the converter working? Is there a way that I can have overhead lights on without having the converter running?

[Reverse_snowbird]

The first thing to check would be your trailer batteries.

The fan near the converter turns on when it gets overheated. The fact that it's running all the time indicates that the converter is constantly trying to charge the batteries. The fact that the overhead lights aren't working probably means that the batteries are dead.

You need those batteries to work to operate the trailer brakes, so you need to address that immediately. You can check them yourself or take them to an auto supply store that can check to make certain that they will hold a charge.

Overhead lights run off the battery when you're not plugged into shore power. The converter takes the shore power and uses it to charge the batteries.

Welcome to the forum!

[auroraRNT]

When you plug your RV into an electrical source, the converters job is to reduce 120 volts AC down to 12 volt DC to supply power to all of the 12 volt appliances and accessories in the RV. Answer is no.

[timotheius]

Thanks Snowbird. Yeah the battery is a no-go. It is currently disconnected because it is old, corroded and looks pretty much like junk. I just thought that as long as I was "plugged in" to AC power I wouldn't need a battery. Based on your response, I guess that's wrong?

[Reverse_snowbird]

Originally Posted by timotheius

I just thought that as long as I was "plugged in" to AC power I wouldn't need a battery. Based on your response, I guess that's wrong?

That's probably correct (assuming that the previous owner hasn't modified anything)
You could disconnect the battery and that would eliminate the converter trying to charge the battery and eliminate the fan noise. Just leave the converter on so that it will operate the 12v side.

But if you're going to move that trailer, you'll need the batteries.

[5picker]

The converter's fan runs when trying to charge the battery(ies) or... if the combined load of 12v items gets great enough that the fan has to come on. We don't know if the fan running is because your battery(ies) are bad and the converter is constantly trying to charge them or whether your 12v loads are great enough the fan runs.

No, you do not need a battery if you never move your R/V... every 12v item will run from the converter... but... some older model converters used the battery as a buffer for the 12v system and did a much better job if there is a battery in the system.

I don't know what converter you have in your 2009 model R/V but it would be worth a try to unhook the cables coming to the battery from the converter and see how your converter acts.

If you have multiple wires that connect at each of the battery posts, you may have to connect them together (with a bolt through the eyelets and taped up - all the wires on the positive together and separately, all the wires on the negative post) to get everything to work off the converter.

[wmtire]

The problem you will have with disconnected battery cables though, is you have to make sure the positive cable(s) are taped up or not touching anything metal so they don't short out the converter, which is still sending a live charge to the end of the cables.

This thread may help you;

https://www.forestriverforums.com/fo...ts-157524.html

Please read the link there called "Converter or Inverter, they are different" to give you some basics.

[weirba]

Another way to think about the set-up is that all your lights and 12Volt appliances are powered by your battery bank and when plugged into shore power the converter maintains the battery bank.

By removing the battery bank you are changing the process so that the converter is directly powering any lights and 12 Volt appliances you have turned on.

I would suggest you get you battery replaced asap and you will see an immediate change in how much your converter runs.

[Sbosserman]

Originally Posted by Reverse_snowbird

That's probably correct (assuming that the previous owner hasn't modified anything)
You could disconnect the battery and that would eliminate the converter trying to charge the battery and eliminate the fan noise. Just leave the converter on so that it will operate the 12v side.

But if you're going to move that trailer, you'll need the batteries.

Not a good idea to run the converter without a battery. The batter also helps to filter out any “ripple” voltage that the converter may have. That “ripple” would be recognized as a hum on any 12 volt audio or video accessories in the rig such as the radio, tv, audio amplifier, etc.

Alway keep a good battery connected to the converter.

[tomkatb]

lots to learn.

The converter is a 4 voltage automatic battery charger. Various rates of charge for various situations. referred to as a smart charger as it does its thing automatically. Typically they charge at 40-60 dc amps.

The battery is a storage device and a wide spot in the line. If the demand for power is greater than the converter can provide that could blow fuses. Typical today with inverters. So the wide spot can supplement the converter to provide what you need.

I have only heard my converter fan once. Because it only operates when the unit is struggling. Yours would sense no battery and run full tilt boogy all the time I suspect. Making the noise.

It takes almost 24 hours to recharge battery banks.

If you never plan on overnighting any where not having a battery is maybe ok. The vehicle is not legal to tow however.

The use in your case of an inverter is not a good plan. They typically can consume hundreds of amps. Likely you have 50 or less without a battery.

Moving forward. I would park the rv for a long weekend. Use the converter to recharge the battery bank 24 hours.

Then flip the battery disconnect off. Measure the batteries at the terminals with a voltmeter after waiting an hour. Voltage should be 12.6 or more. If not the batteries are likely not ok. Replace them with a cheap car battery or two. if you are sure that you will not need to sleep overnight somewhere unplugged. I recommend lithium.

If the converter fan then runs all the time I would replace it.

[MR.M]

Originally Posted by Sbosserman

Not a good idea to run the converter without a battery. The batter also helps to filter out any “ripple” voltage that the converter may have. That “ripple” would be recognized as a hum on any 12 volt audio or video accessories in the rig such as the radio, tv, audio amplifier, etc.

Alway keep a good battery connected to the converter.

That's not entirely accurate . I've run my unit on converter for months at a time only connecting battery to keep charged every couple months . never any adverse effects . some units you need the battery to help run slide outs, or tongue jack etc otherwise converter can run all your 12 volt needs with out battery or without adverse side effects .

[Reverse_snowbird]

A couple of things.

The OP (original poster) said that his battery is obviously 'corroded and pretty much looks like junk'. So that probably needs to be replaced.
Disconnecting the negative cable would effectively disconnect it.

That rig probably doesn't have an included battery disconnect.

I forgot about slideouts. From looking at the floorplan, he has 2 slideouts which will probably need batteries to retract them.

So the OP should replace the battery and if the fan continues to run for long periods of time, come back for more troubleshooting.

[timotheius]

Originally Posted by wmtire

The problem you will have with disconnected battery cables though, is you have to make sure the positive cable(s) are taped up or not touching anything metal so they don't short out the converter, which is still sending a live charge to the end of the cables.

This thread may help you;

https://www.forestriverforums.com/fo...ts-157524.html

Please read the link there called "Converter or Inverter, they are different" to give you some basics.

This was very helpful. Thanks for providing the link.

[DougW]

Originally Posted by weirba

Another way to think about the set-up is that all your lights and 12Volt appliances are powered by your battery bank and when plugged into shore power the converter maintains the battery bank.

By removing the battery bank you are changing the process so that the converter is directly powering any lights and 12 Volt appliances you have turned on.

I would suggest you get you battery replaced asap and you will see an immediate change in how much your converter runs.

This is correct, the system is designed to operate with a battery installed and it will work the best with a battery.

The fan is probably running because the converter is trying to charge the battery. Th converter supplies higher voltage and amperage until it detects the battery voltage is approaching a full charge, then the converter should reduce the voltage to a maintenance charge. With no battery connected the charger is probably running full speed ahead and that is when the fan kicks up to high speed.

I also reiterate the need for the battery when towing for the break away switch to be able to operate the brakes if the trailer gets loose from the tow vehicle.

[timotheius]

Originally Posted by Reverse_snowbird

A couple of things.

The OP (original poster) said that his battery is obviously 'corroded and pretty much looks like junk'. So that probably needs to be replaced.
Disconnecting the negative cable would effectively disconnect it.

That rig probably doesn't have an included battery disconnect.

I forgot about slideouts. From looking at the floorplan, he has 2 slideouts which will probably need batteries to retract them.

So the OP should replace the battery and if the fan continues to run for long periods of time, come back for more troubleshooting.

Sooo...don't laugh but the positive battery cable terminal ring has actually corroded to the point that it just fell apart and broke off. So, ever since I bought this RV two weeks ago, it has been parked in my back yard operating strictly off power provided by the converter. (the two slideouts have been working just fine despite no battery power). The battery "bank" is currently just 1 corroded junk group 24 battery. Based on what everyone has said, I'm going to replace it tonight with a good working group 27 battery that I have in my garage. (and replace the broken terminal ring, of course). There actually is a battery disconnect switch built into the system. It appears to interrupt the negative battery cable. Is that normal or should I change the wiring so that the switch interrupts the positive cable instead?

[Reverse_snowbird]

Originally Posted by timotheius

I'm going to replace it tonight with a good working group 27 battery that I have in my garage. (and replace the broken terminal ring, of course). There actually is a battery disconnect switch built into the system. It appears to interrupt the negative battery cable. Is that normal or should I change the wiring so that the switch interrupts the positive cable instead?

Not going to laugh. It happens.
Sounds like a good plan. The battery should be a deep cycle marine battery.

That battery disconnect was probably installed by the previous owner and installing on the negative cable is correct. When in storage, disconnect the battery when it's fully charged and it will last a long time. All these rigs have parasitic draws which will deplete the battery if connected in storage.

Glad the slides work when on shore power. That's a good thing.
Keep us posted.

[Bob K4TAX]

Look at it this way, the battery is the primary source of power for the 12-volt system, regardless of shore power. Thus lights, slide, awning, pump, etc. require a good battery to operate properly. The converter is the secondary source of power for the 12-volt system, i.e. it charges the battery.

I know some will say all of their 12-volt systems will work with just the converter and no battery. OK so be it, but with no battery, one is limited to the maximum current capability of the converter. This most likely is less than the demand of the higher current demand systems such as the slides, awning, jacks, stabilizers, etc. It is never advisable to operate the system with no battery installed or with it disconnected.

The fan in the converter is running because the converter is working really hard to keep up with the 12-volt current demands.

Get a new battery, clean ALL of the connections, and make sure they are tight. The converter will likely still run until the battery is fully charged. And may come on from time to time.

Bob

[timotheius]

Okay cool. I have another question, about lithium batteries. At home I have a 12 volt 160ah lithium battery that I bought to power high-draw systems in my boat, such as radar and chartplotters and stuff like that. But I was told that lithium batteries need a special charger, so I keep that battery isolated from the charging system in my outboard motor and just remove the lithium battery at the end of a days use and hook it up to an external charger. If I wanted to use that same battery in my RV, are there any concerns with charging a lithium battery with a RV's converter? Will a converter do any sort of damage to the lithium battery by charging at a different rate? I really want to protect that lithium battery. It cost about $1,000 and I want to get as much life out of it as possible. But at 160 ah, it is a huge powerhouse and could be a good option for the RV.

[boondocking]

Unless the original converter has been replace with a newer version it would not be lithium compatible. Do not use it it charge your lithium battery.

[Reverse_snowbird]

Originally Posted by timotheius

But I was told that lithium batteries need a special charger, so I keep that battery isolated from the charging system in my outboard motor and just remove the lithium battery at the end of a days use and hook it up to an external charger. If I wanted to use that same battery in my RV, are there any concerns with charging a lithium battery with a RV's converter? Will a converter do any sort of damage to the lithium battery by charging at a different rate? I really want to protect that lithium battery. It cost about $1,000 and I want to get as much life out of it as possible. But at 160 ah, it is a huge powerhouse and could be a good option for the RV.

Lithium batteries do need a special charger (in this case a converter) to get it to full charge. However, since you don't need to get it to full charge every time, you can put it in your rv. Your alternative is to use that external charger as a supplement to get it to full charge.

I don't have any knowledge of boat charging systems. I know that in a motorhome, you need a dc-dc converter to protect the engine alternator.

When in doubt, you should probably contact the battery manufacturer for guidance. That's what I'd do.