Livin' Lite Simplicity vs modern MH Complexity

[DavidM]

As some of you may remember, I sold my 16TBS last year to Stu and early this year took delivery of a new Thor Axis 24.1 motorhome. After exploring the new MH for the last few months and barely understanding its systems, let me review some of the differences in the two types of  RVs:

DC Electrical- This is probably the biggest difference. LLs are rather simple, a tongue mounted battery or two that is charged by the 7 pin connector or shore power when available and feeds through the converter to power all DC appliances. My MH OTOH has four primary outputs and inputs to/from the batteries: generator start, chassis battery connection manage by a bi directional relay, solar input and a connection to the converter which powers all DC systems. The lights and appliances are not managed by simple on/off switches. There is a touch screen display that lets you open or close the slide or awning, turn on lights and dim them as required, turn on the A/C or furnace and control the coach's temperature. It is infinitely more complex.

AC Electrical- LLs have a simple shore power connection that feeds the AC part of the converter. My MH has an automatic transfer switch that selects generator or shore power. The touch screen display referenced above has an automatic generator start/stop function that can be based on time or battery state. Some MHs also have a load shedding system to keep from overloading the generator system.

Propane- LLs have a tongue mounted tank that feeds the stove, furnace, and water heater. My MH has an internal propane tank that you must fill at a propane station with a hose. The propane tank level is displayed on the touch screen display. Fortunately it has a simple on/off valve like the one on your propane tank. Most MHs have an electric solenoid that controls the propane.

Tanks- Each tank level on my MH is displayed on the touch screen display, but for the most part the tanks function the same as a LL. You can't do much to automate water and waste flow.

All the above means that a MH is incredibly more complex. I am surprised it all works as well as it does on my MH. But I wonder how it will all work in ten years when most electrical stuff starts to give trouble. I think that this complexity results in a built in obsolescence that will make most motor homes near worthless over time.

That is totally the opposite of LLs that were built simple, with a long lasting structure that will serve you well for decades.

Oh BTW, I am convinced that 98% of MH campers camp at full hook up or at the very least electrical hookup sites. No one on the Thor forum I visit seems to be interested in high DC power usage and particularly the 15-20 amp hour daily parasitic load of my or similar MHs. When you plug into A/C power at a campground that isn't an issue for the user.

David

[GrampaKilt]

In my robust hiking and car tent camping years, I vowed I would never stoop to becoming one of the those RVer's, always holding up traffic with ostentatious rigs that also sully the outdoor experience with all the comforts of home. As I aged, I was forced to admit that I no longer was fond of sleeping in a tent, in the rain on hard, sometimes muddy sites during travels. I rationalized buying a CL by telling myself--it's built to last, it's minimalist and lite enough that a) I don't have buy another vehicle to tow it and b) I can easily keep up with traffic flow, never becoming the typically oblivious RVer at the head of a line up. It was a sound decision and I regret it not one whit. But, sometimes I wonder if changing my beliefs enough to buy a TT would someday open the door to purchasing a MH. May it never be! With that in mind, I recently I asked my LSW to shoot me if ever I am serious about getting a MH GK

[Merlin]

Interesting analysis!  Do the batteries get charged while driving by the vehicle alternator?  Is the fridge compressor or absorption?  Is there an inverter anywhere in the system? Curious minds want to know more too, but these are a start 

[DavidM]

Interesting analysis!  Do the batteries get charged while driving by the vehicle alternator?  Is the fridge compressor or absorption?  Is there an inverter anywhere in the system? Curious minds want to know more too, but these are a start 

Ahh, the curious technical mind needs to know. Happy to oblige:

Most motorhomes have a latching relay device that connects the coach batteries to the chassis battery and alternator when the coach alternator is putting out 13.5V or more. It also works the other way to charge the chassis battery when the coach batteries are full and are being charged with solar or shore power to the converter and putting out 13.5V. I have confirmed that that relay actually works!!

It took some doing but I did get an absorption fridge. The unit I ordered unexpectedly was delivered with a compressor fridge and I assume all afterwards would be delivered with compressor fridges. The dealer graciously let me have one of his almost identical stock units that did have an absorption fridge and had a 100 watt solar panel to boot. So all in all it was a win for me.

I am glad I got the absorption fridge, because a compressor fridge would add 50+ amp hours daily and we always dry camp and mostly at shady sites.

No there is no inverter. I am happy with that. I will use a portable cigarette lighter plug in inverter to power the charger for my e-bike (another story) when we are underway and have lots of chassis power. I have no other AC loads.

One other electrical note. My 16TBS used about 5 amp hours daily for parasitic loads like the CO monitor and the controls for my absorption fridge. This MH uses 3-4 times more. Who knows where all of that power is going. I suspect a lot is being consumed by the touch screen display. But the only way to kill it is to disconnect the battery, but then the fridge won't work. Please give me a MH with simple switches and not this electronic crap, but unfortunately they aren't made that way anymore it seems.

David

[djsamuel]

No there is no inverter. I am happy with that. I will use a portable cigarette lighter plug in inverter to power the charger for my e-bike (another story) when we are underway and have lots of chassis power. I have no other AC loads.

Do you have a generator built in?  How do you run the A/C in the motorhome while driving?  Do you use the cabin A/C or is there a separate system powered by the MH engine?  More curious minds here. 

[DavidM]

No there is no inverter. I am happy with that. I will use a portable cigarette lighter plug in inverter to power the charger for my e-bike (another story) when we are underway and have lots of chassis power. I have no other AC loads.

Do you have a generator built in?  How do you run the A/C in the motorhome while driving?  Do you use the cabin A/C or is there a separate system powered by the MH engine?  More curious minds here. 

Hello curious mind:

Yes I have a 4 KW gasoline powered Onan generator. The RV is also gasoline powered. It has been too cold so far to think about running the A/C here in Connecticut. The coach chassis does have an engine driven A/C compressor that is part of Ford's stripped chassis supply to Thor. Thor takes that stripped chassis and build their MH around it. Click on the attached link for a pic of the stripped chassis.

So there are two separate A/Cs, one powered by the chassis engine and the other powered by the coach's AC system which will be generator power while underway.

In our climate up here I suspect that the chassis A/C will be enough to keep us cool. But in warmer climates others start the generator and run the coach A/C as well. It burns about 1/2 gph of gas so it will drop the mpg by about 1 mpg when you do this.

David