Converter or inverter

[pushtrk99]

would a 2000 forest river have a inverter or converter-and how are they different--- house batteries charge perfect when plugged in at campground but battery doesn't get charged going down the road from the alternator- any help is appreciated--RICH

[C.Martin]

An Inverter takes DC power and turns it into AC.

A Converter takes AC power and turns it into DC. Also called transformer-rectifiers.

The tricky thing is...many of the designs used in RV’s today blend the two into one device. My Magnum Energy MS2812 is refereed to as a pure sine wave Inverter...but it also acts as my converter. The advantage to this is...it can pass thru AC from a shore or generator usually by being connected to the transfer switch. It doesn’t need to do two operations such as convert AC to DC...and then turn DC back into AC.

Rv’s with no Inverter...will usually just have a stand alone Converter. It recharges the battery(s)...and supplies dc power for lights, pumps, circuit boards. While AC power is just distributed.

For RV’s with inverters...many use the popular one that can also recharge the batteries. A few may still have a stand alone converter and a separate stand alone Inverter.

Confusing...but hope that helps.

As far as charging...your alternator puts out 12v already. It doesn’t need to be inverted or converted to recharge your batteries. It needs to be connected. This is managed in most Motorhome by a Bi-directional relay commonly referred to as BIRDs or BIMs or Battery Combiners...they follow a propgramed protocol for what conditions need to be met...and then close a relay. That way the alternator can charge the house batteries.

[followingsea]

Originally Posted by pushtrk99

would a 2000 forest river have a inverter or converter-and how are they different--- house batteries charge perfect when plugged in at campground but battery doesn't get charged going down the road from the alternator- any help is appreciated--RICH

It depend on how your MH is equipped.

House batteries are charged two ways. Using 120 vac just like any battery charger.

Your engine alternator can also supply 12 vdc to the house battery when the engine is running. There should be some sort of protective device (BIRD on mine) so your house battery does not drain your engine start battery. When the engine is running and your chassis battery is charged it activates a solenoid to connect to and charge your house battery.

If you have a start boost switch to allow you to use your engine with the house battery, this is the same solenoid. I had to replace this solenoid.

My first MH did not an inverter to convert 12 vdc to 120 vac. A got a 700 watt inverter for that purpose but it had to be connected manually.

My current has a very expensive inverter/charger that performs both functions along with a BIRD. For example, if I start the Onan generator to charge the batteries it has a delay to allow the genny to warm up before charging the batteries. It also controls the rate of charging.

It is a little complicated until you figure it all out. Part of owning an RV.

[twinboat]

In you vintage MH, you may have a simple solenoid the closes when you have the engine running, to connect the chassis battery to the house battery, to charge both while under way.
Nothing to do with converter/charger OR inverter/Charger, they work with shore power.

You should also have a boost switch that connects the chassis and house batteries.

Both the engine running and the boost switch close the same solenoid. The solenoid a fail often.

Find it, by having someone push the boost switch on and off, while listening for it to clunk.
Once found see if the voltage from each large post is the exactly the same, while its held. If not replace it.

Be sure the replacement is a contionues duty solenoid.

[pushtrk99]

My/our MH is a 2000 Class C Forest river and does not have a booster switch & I have changed these parts and nothing has changed- I have 12 volts coming to solenoid but don't have 12 volts on other side of solenoid when motor is running, something is not activating solenoid to let juice to go through

[twinboat]

The solenoid on the left is the isolation relay. The one that handle a charging while running.

You should see 12 volts on each large terminal, measuring to ground.

1 side will be house voltage the other side chassis voltage.

If not, a cable may have been left off the chassis battery.

Next test. One of the small terminals is grounded and the other is feed 12 volts thru the ignition.

If you don't see 12 volts there, there has to be a fuse somewhere, protecting the wiring. Mine was hanging out near the alternator, looking like a connector not connected.

The solenoid on the right is a latching relay for the house disconnect.

[pushtrk99]

The house disconnect solenoid would not be involved with this problem I assume ? When I get a warmer day I will go to storage and see if I have 12 volts on both sides of the solenoid with key on and will check for fuses up front which I haven't done yet thanks Rich

[C.Martin]

If your water pump is working...the house disconnect is closed.

The alt. charge gets to the house batteries thru a different relay. It isn't as simple as turning on the key. It is designed to let your alternator first charge the chassis battery. When the voltage reaches a certain level...and the chassis battery is within parameters and the generator is not running...the relay closes. Likewise...when plugged into shore power...after your house batteries are charge with the ignition off...it can close to let your converter charge the chassis.

The best thing to do is find this relay on your rig...take a picture of the model number...then research the mfg. Spec sheet. Many include a troubleshooting proceedure.

http://precisioncircuitsinc.com/prod...mp-continuous/

Thats a link to one of the many used in RVs. It will give you an idea of how they work. Some are two part...control module and seperate relay. They are all being phased out and replaced with solid state switching devices it seems.