[Archived]

Hi Georges, On my Liberty, on the control panel marked line one, are all
“red” circuits that are run off the inverters; Refg, TV, coffee
maker, front and back outlets, etc. The rest, like the hot water heater, engine
block heater, external outlets, cruseairs, etc. work without the inverters
being switched on. Along with converting power, the inverters charge the
batteries too. So when I’m plug into 50 amps (or running the gen set) I’ll run the inverters
with the battery charger on and anything else that I need at the time. When
I’m dry camping during the night, I’ll turn one inverter off all together and
just run the inverter that runs the tv and refg with a few lights so I can conserve my house batteries.

There are lots of different ways to run them, depending on what you need to
do.

Fred

[JIM]

Fred If you shut all breakers off that go to the inverter that you shut off aren’t you accomplishing the same thing? Rick

[Archived]

For our use of the coach the way we deal with inverters is simple. I never turn them off.

Except when changing house batteries or doing some electrical work and I want all electric power off they are always on.

When the generator is on or we are connected to shore power they are maintaining the charge on the house batteries. When we are not running the generator or hooked to shore power they are keeping power to the circuits powered by the inverter(s) which makes life real simple. In that way we always have power to the refrigerator, TV, outlets and whatever other circuits the inverters power.

While I agree with Fred in shutting one off to save power I am now of the mind we all spend a lot of money to be owning the “ultimate” in motorhomes and I want all the convenience and luxury our coach provides. So I don’t want to live in our coach as though it is an aluminum tent reading by candlelight so if I am not connected to 50 amps of shore power I want to hear that generator working away. I’ll never wear it out, might as well use it.

The one luxury or feature I do not use is “auto-start”.

[Archived]

Jon and I have had this discussion on numerous ocassions and even tho’ I do not own a high dollar conversion, I have most everything except auto start. Most of the time we are on the genset and do not use the inverters.

When I shut it down for any length of time, I usually kill ALL OF IT and this includes the inverter. Once a month I might run the inverter off the plug to bring the house batteries up to snuff, but I disconnect after about three days. I am always concsious of the possibility of fire in the shop while being on “the plug” as Jon would say, so I unplug it. I also do not want to risk cooking my house batteries (boiling over and losing fluids) so I unplug it.

Running on a generator 100% of the time, I really don’t know why I even have an inverter. “We all spend a lot of money to be owning the “ultimate” in motorhomes and I want all the convenience and luxury our coach provides.” Could it be that all of us are victims of over-kill and only need about 50% of all this to begin with?

An Alum tent? That is rich, I know one nimrod that will not appreciate that for sure. Mine is a Motel Six on Steroids.

BCO

[Archived]

Hi Rick, yes you are right.
But I to try and conserve the house batteries when dry camping, so I turn off
one of the inverters. You raise a good question, how much juice does an
inverter take to run? I always thought the less “draw” on the batteries the
longer they will last but am I actually doing more harm than good? I get Jon’s
“aluminum tent” comment and it’s a good one, these conversions are meant to run
full bore. But I’m originally from Wisconsin, we are always looking for a way
to save anything!

Fred

[AL]

The first thing to understand is that some use the terms inverter and charger as though they are one in the same; they clearly are not. The confusion likely comes from the fact that most coaches have a single device that charges the batteries (charger) and produces 120VAC from the batteries (inverter).

If you have a source of 120VAC, then your inverters should be off or in bypass. Most modern inverter/chargers have the intelligence to bypass the inverter when 120VAC is present on the input, even if you have the inverter turned on. If your inverter has this intelligence then you need to ask yourself if you want your inverter to produce 120VAC when the commercial and generator aren’t supplying 120VAC to the coach. If you are dry camping or putting your coach into storage would be the times when you may want your inverters off. When dry camping your may only want one inverter on, if you have two inverters. You may want the one on that powers the refrigerator but not the one that powers other 120VAC items. You would do this only to prolong battery life.

My inverters are on except when I put the coach into storage (no power available). This way the refrigerator stays powered even if campsite power fails or when I’m driving without the generator running, which I seldom have the generator running when I’m driving. The Country Coach ait keeps the coach cool without the use of the generator.

Most autostart generator systems aren’t going to keep the refrigerator cold if the inverters are off and you lose campsite power while you’re out exploring the town. Most autostart systems only start the generator when the voltage of the house or generator drop below a set voltage and some will do so based on reaching a temperature threshold in the coach. With your inverters off the battery voltage will not trigger the generator’s autostart function for a very long time. It could be days depending on what DC systems are on and the state of charge of your batteries.

If you have an intelligent inverter, leave them on except when you are leaving the coach unattended without commercial or generator power.

[Rick & Denise]

Before this gets confusing to everyone and the answer to Georges question gets difficult to find within the answers perhaps it is best if Georges shows a photo or tells us exactly what brand and model inverter he has.

The inverters and the manner in which “inverters” have been installed has changed over the last couple of decades and to give Georges an answer that directly relates to his coach.

Not only have inverters (or inverter chargers) changed over the years, the installations by converters have changed, such as some converters running all 120 VAC through the inverter chargers (Vantare for example) but some coaches have been modified from how they were originally built so the answer may be generally applicable to all, or it may be specific to Georges coach.

[Archived]

This may be applicable to a great number of coaches equipped with inverter/chargers but it is definitely applicable to Rick’s Liberty.

If his inverter panel switch is “on” and his 120 volt CB to the inverter is “on” the inverters are charging the batteries and supplying power to the inverter circuits that particular inverter is connected to.

The charger is a three stage which has bulk, absorbtion, and float stages. If the inverter has shore or generator power available it is an excellent battery charger and maintainer and will not damage the batteries. The only problem with leaving the coach powered and the inverters on to maintain the batteries is if 120 volt input power is interrupted the inverter switches from a charger to an inverter supplying power to its 120 volt circuits. When that happens if the power is not restored it drains the house batteries. Even if all inverter circuits are turned off, the inverter draws power as Fred correctly notes and that small power draw will be a load on the batteries.

So the bottom line on leaving inverters “on” is if the coach is monitored so in the event of a power loss everything can be shut down then leaving them “on” makes sense because they keep the batteries maintained. If the coach cannot be monitored easily or regularly (I am near my coach daily and know if power has been disrupted) then it is best to put the house to sleep by turning off the inverters and all house battery master switches.

This may be exactly true for Georges coach also, but until we know his type inverter and how it is set up all that can be said is it is true for Rick’s coach and a number of others.

For those who dry camp as Fred does, he is correct in energy management but if he relies on auto-start when the house battery voltage gets down, then both inverters should be “on” so he can get a full battery charge in the shortest period of time. As a note, dry camping usually requires the charging rate on inverters to be set to a high rate. If Fred were to leave the settings unchanged and on a hot day, with low batteries try to turn on a couple of ACs while on 50 amp shore power it is probable he will trip some campground breakers so the point is in energy management we have to understand our systems to the extent we have our inverters set for the conditions as well as the battery type used in the house. If the inverters are not set to the charging protocol for the type house batteries it is possible for the inverter to damage the house batteries.

Sorry Georges, but we have to develop an understanding of several things about our coaches for them to serve us as intended, and inverters are important to know.

[Russ]

Understanding electricity has always been something of a challenge for me and a Prevost has no shortage of electrical systems. Here is a photo of my inverter bay and I do not know how they are wired.

[Bill]

Georges,

Your inverter/chargers look to be Freedom units. You can control the charger and inverter indepently. I’ll skip discussing the charger as that wasn’t your question and the charger has little if anything to do with inverter.

Each inverter supplies 120VAC to specific and seperate loads. You should have a power panel for each that contains the circuit breakers for the 120V circuits supported by each inverter.

When the inverter is on it will supply 120V from commercial or generator power first. If commercial or generator power is present the inverter is sitting idle while the commercial or generator power is supplied directly to whatever is powered through that inverter.

When commercial or generator power is not present and the inverter is on, the inverter supplies 120V it creates from the house batteries. If commercial or generator power is restored the inverter will automatically return to idle and supply the commercial or generator power to the coach systems.

If you have or commercial power leave the inverter on if you want to make sure the house batteries supply power in the event of a power failure. This would be typical. If you are on house battery for a long time then you need to manage battery drain. This could include turning one or both inverters off. As an example, I only the inverter supplying power to my refrigerator on and the other inverter offf when our coach was on a 3 1/2 day ferry trip and I wanted to keep the fish frozen.

When your coach is stored the inverters should probably be off, especially if you don’t have generator autostart. I always store mine with the inverters off even if I have commercial power. If I have commercial power in storage I have the chargers on and inverters off.

I hope this answers your question,

[Bob]

Yes, they are Xantrex Freedom 2500W inverters. I always shut them off as well as both 24V and 12V mains when it is parked unplugged for more than 3 or 4 days. I was just wondering if they should be on and why, while plugged into shore power.

[Archived]

Most , if not all modern inverters, have a LBCO (low battery cut off) and will shut down the inverters at the set voltage and in theory, save your batteries. The problem is, there are other 12 or 24 volt loads that will continue to drain the batteries over time. So I agree, if your bus is going to set for an extended time without gen or shore power, shutting everything down makes sense.

[John]

Georges,

I always leave my inverters on while the coach is plugged in, unless it is in storage. The rationale being that power will be maintained if there are short power outages or brown outs. Frankly, another reason I leave them on while on commercial power is so I don’t forget to turn them on when we unplug headed for our next stop. I seldom run the generator while driving.

[AL]

“Most , if not all modern inverters, have a LBCO (low battery cut off) and will shut down the inverters at the set voltage and in theory, save your batteries. The problem is, there are other 12 or 24 volt loads that will continue to drain the batteries over time. So I agree, if your bus is going to set for an extended time without gen or shore power, shutting everything down makes sense.”

Tom and Gil are correct. The question you have to answer is how high is your confidence level that when parked (stored) your shore power will always be on. Notice Tom’s comment the inverter will shut down at a low house battery voltage if power is interrupted. What he said is that by then the batteries are already at a very low voltage, and whatever phantom loads are on your house batteries such as alarms, clocks, thermometers, etc. will finish killing off your batteries. One simple problem can effectively ruin your batteries or at least damage them.

I want my inverters on all the time to maintain the batteries, but having said that I will shut everything down if I cannot monitor the coach. In your position I would ask myself if I had enough confidence in the shore power to leave the inverters on and the house master switches on. And then only if I could monitor the coach daily. I pick daily as an interval because even if something interrupts shore power, my batteries will not go dead within that 24 hour period. Power can be interrupted by the shore power being turned off from a power outage, someone messing with the switch, your transfer switch failing, or other similar problems. On my coach monitoring means I hear a distinct hum from the transfer switch and the operation of a fan as soon as I step into the garage. And my garage is 15 steps from the house door.

Being a belt and suspenders guy I lack total confidence in anything mechanical. So I will tend to choose the option that has the least risk. You might feel comfortable leaving the inverters on, especially if you have all other electrical loads turned off such as the refrigerator. Doing that certainly keeps the batteries charged and eliminates the need to go through the process of shutting it all down. There is no correct answer to this question.

[Hector]

Taking the assumption that you will be leaving your bus for an extended time, say a week. If your parked in an area that can support the running of your generator, then setup the auto-start. You first must be confident that the auto-start function works properly and you have setup the start/stop functions to your liking.

You have to correctly set the time in order to use the “quiet time”, then adjust the start paramiter, I use 50% state of charge and then setup the run time to stop the gen at “float.” There are many different paramiters you can use, but that works best for me. I know it works, since I have verified it’s operation at home. Mine will set with normal A/C loads and the fridge for 20 hours before reaching 12.2v.

Using the auto-start then keeps you from having to empty out the fridge by not shutting town the entire system.

PS – Make sure you have enough fuel onboard.