The "all electric" coach is probably a misnomer

[holstein13]

A couple years ago when I was placing my order for my new coach, I had to decide if I wanted an "all electric" coach. At first mention, that sounded great -- no more propane use.

After having the coach for a year and a half now, I'm glad I took the "all-electric" option, but there are some negatives and I wanted to talk about the pros and cons.

First of all, the idea that you can use your coach, year round, without burning fuel is a misnomer. The "all electric" appliances will still burn fuel in certain circumstances, but it won't be propane. There are essentially four systems impacted by this option:

1. Cooktop / Oven - In my old coach, we had a propane cooktop and in the new coach, it's an induction model. While the induction model is usually adequate, I'd say the propane model was much more powerful and easier to control. Sure, it caused more humidity in the coach, but it was easier to cook with and didn't require the generator to be on while boondocking. The induction cooktop is easier to clean and does the job. The electric oven is a GE Advantium Microwave / convection oven. It is a bit smaller than the traditional propane oven. Like the cooktop, I prefer the gas oven to the electric oven. But since RVs typically come with a microwave anyway, the electric ends up being a space saver. Some folks never use their gas ovens.
2. Refrigerator - This is the old debate between propane and residential. I think most of you are familiar with the debate so I'll boil it down to more room and better temperature control in the residential refrigerator versus less electric power usage with the propane model.
3. Heating / Furnace - The "all electric" option uses an electric heat pump to heat the coach until the outside temperature falls below 40 degrees, then it draws upon the hydrostatic water heater to provide heat. If the temps don't fall too low for too long, the two electric heating elements in the water heater will do an adequate job. However, if temps fall much lower for much longer, the system will need to burn diesel fuel to keep up. This is not a bad tradeoff and probably saves us a ton of money, but it's something to consider. The heating system will still burn fuel in extreme cases.
4. Water Heater - Again, the water heater uses the hydrostatic heater in the basement that is heated by electric heating elements or a diesel burner. For short showers with little water flow in warm climates the electric heating elements are more than adequate to provide nearly continuous hot water, but in many other situations, the diesel burner must be activated to heat the water.

So there you have it. I'd still take the electric option if I had to do it over again. It saves us money while we are hooked up to electrical sites and I'd rather run out and add a few gallons of diesel to my tank than have to lug a spare tank of propane or move my coach when we are boondocking. But it's not as simple of a decision for everyone.

ON EDIT: I updated this to add the oven description. Also, I should add that I've got a 600 watt solar array that was not part of the electric package. It was extra.

[Mr_Mark1]

Many of the Prevost conversions use the Crestron system. Ours is intergraded with 3 i-pads (2 large inside, one small outside) that controls almost every function in the coach except the engine. We also have three 'hard wired' systems though-out the coach (one on the dash, one mid-ship and one next to the bed).

It is also connected to my smart phone so I monitor the coach when I'm away from it and can turn on/off air conditioners and lock/unlock the coach, etc. I love this feature

MM.

[bluwtr49]

Mr.Mark wrote:
"Do most folks have a battery monitor to monitor the state of charge (SOC) of their house bank? "

Absolutely, we can monitor the state of charge on our battery bank (house and chassis) at a glance on the i-pad.

MM.

Yep, same here but on my old(er) coach not on an external device. Silverleaf monitors chassis battery and the CMP (coach monitor panel) monitors the house batteries, solar status, and all the other vital functions. In addition the inverter remote also measures hose batteries status, charge/discharge and etc.

Most coaches will offer some of all of the same functions.

[timjet]

Mr.Mark wrote:

Absolutely, we can monitor the state of charge on our battery bank (house and chassis) at a glance on the i-pad.

MM.

Monitor from your I-pad, very cool. How do you do that?

I have a dedicated display attached to the boat.

[Mr_Mark1]

"Do most folks have a battery monitor to monitor the state of charge (SOC) of their house bank? "

Absolutely, we can monitor the state of charge on our battery bank (house and chassis) at a glance on the i-pad.

MM.

[timjet]

Ok, just trying to wrap my head around the differences between how my boat is wired and a typical DP. It sounds similar but more things are automatic in a DP.

The engine alternator output is automatically directed to the battery bank with the lowest charge, either the house or chassis battery bank.

When running down the road, the inverter supplies AC power to the residential fridge and the engine alternator keeps the house bank topped up along with the chassis battery bank. While camping the refrig get AC power from shore power or if that's not available, the generator.

Do most folks have a battery monitor to monitor the state of charge (SOC) of their house bank?

[Mr_Mark1]

Kayteg1 wrote:
What you might want to know, roof AC takes equivalent of 1 - 1.5 HP, so even with 3 of them, the 400HP + engine will never notice the load.
I am intrigued with 4 alternators though. My vintage conversion has single alternator, what I figure out is about 8,000W (it is in size of good bucket) and that alternator was build with passenger bus in mind, with lot of (incadescent) lights and gadgets.
What would make one putting 4 alternators?

Kayteg1,

The alternators are not the huge type. The extra alternators are to power the four 3,500 watt inverters so we can have full house function driving down the road. And, we can run any house item on battery power, just not all at once or we will drain the batteries quickly. The Lithium Ion batteries are expected to last 10 yrs. and can be rebuilt at a much cheaper cost vs. replacement. The price of the batteries have really come down over the years but still are a big commitment.

We lost power the other night at a RV park in Mississippi. About 1 AM, a car hit the telephone pole at the street. At 4 hrs. of inverter use (fridge on, hot water tank on, two small fans circulating air, engine battery charger on, air compressor for air seals activated).... we had 69% of battery life left. At 30%, the batteries will cut off and go into 'safe mode' (coach will be totally dead) if I didn't have the genny set to come on. Somewhere above that 30%, the generator will pop on automatically to recharge when the 'low battery' feature is activated. I can also set the generator to come on the second power is lost (didn't have that part activated).

To extend battery power, I could turn on the Espar to heat water and turn off any chargers, compressor, etc. (temporarily).

MM.

[Mile_High]

timjet wrote:
OK, stupid question from someone who does not own a MH yet; How do you power a residential refrig when driving down the road. Large battery bank and inverter?? Surely you don't run the generator all the time.

On ours, they upgrade the inverter from 2000 to 2800 watts and add 2 additional glass mat batteries to the existing 6 when selecting the residential fridge option, so it would seem the extra 800 watts is for that fridge. Otherwise the inverter runs guite a few other things on-board such as the TVs microwave, etc.

When shopping, DW really likes her gas cooktop. Seems to be a big transition in the last two or three years towards electric. Gas wasn't a top priority, but preferred. We looked at a Tour 2011 that had the auquahot, so the only thing that used the 28 gallon LP tank was the cooktop. I looked at my wife and said the gas in that LP tank will last as long as the loan! 🙂

[Kayteg1]

What you might want to know, roof AC takes equivalent of 1 - 1.5 HP, so even with 3 of them, the 400HP + engine will never notice the load.
I am intrigued with 4 alternators though. My vintage conversion has single alternator, what I figure out is about 8,000W (it is in size of good bucket) and that alternator was build with passenger bus in mind, with lot of (incadescent) lights and gadgets.
What would make one putting 4 alternators?

[Mr_Mark1]

timjet wrote:

Mr.Mark wrote:


We don't have solar but have 3 Lithium Ion house batteries, 4 starting batteries for the engine (24 volt) and one battery for the generator. We have four 3,500 watt inverters, four alternators on the engine that will allow us to use four roof airs without the generator running going down the road.

MM.

Wow, Mr Mark you could power a small town. Just curious, on a hot day with all air conditioners running and climbing a hill do the alternators sap enough power to notice a lack of power to the wheels?

Anyway your post explains a lot. My boat has a similar configuration whereas the alternators will charge the house batts while underway. My boat refrig is DC/AC so no need for an inverter though I have one.

What I didn't know is if the current from the alternator could be directed to either or both the house and engine start batts. Sounds like it can. Is there a selector switch to direct this current?

Mr. Timjet, there is no selector to direct the alternator current, it's all automatic. I can turn off the charger for the engine batteries but I leave it on unless I'm parked and on inverter power. If I ever really needed all 4 air units while underway, I would crank up the genny as it needs to run and that would leave all the power for the engine (20kw Kohler genny). Also, I have never noticed any difference when using air by inverter and power to the wheels.

Honestly, there really is no need to run all four air units. Two is enough unless it's very hot, then I will run three. Having four units is really overkill and gives you an option if one of the other air units goes out.

We have four 13,500 btu units and they are designed to be extremely efficient as there are no 'hard' corners in the ceiling ducting (CAD designed). This design allows for a stronger force of air with minimal noise. If the air is on and you walk under a vent, it's rather shocking of the 'woosh' of air hitting you on the head compared to the noise.

MM.

[timjet]

Mr.Mark wrote:


We don't have solar but have 3 Lithium Ion house batteries, 4 starting batteries for the engine (24 volt) and one battery for the generator. We have four 3,500 watt inverters, four alternators on the engine that will allow us to use four roof airs without the generator running going down the road.

MM.

Wow, Mr Mark you could power a small town. Just curious, on a hot day with all air conditioners running and climbing a hill do the alternators sap enough power to notice a lack of power to the wheels?

Anyway your post explains a lot. My boat has a similar configuration whereas the alternators will charge the house batts while underway. My boat refrig is DC/AC so no need for an inverter though I have one.

What I didn't know is if the current from the alternator could be directed to either or both the house and engine start batts. Sounds like it can. Is there a selector switch to direct this current?

[William_B]

No big deal but it's hydronic, not hydrostatic:)

[holstein13]

wa8yxm wrote:
... it also can "Burn" engine heat when you are on the road and pre-heat the engine before you leave in many cases., Very handy.

I thought about mentioning this but hesitated because I find that I rarely heat the coach while traveling. But when I travel in very cold weather, you are correct. It's great to have the coach heated by the, otherwise wasted, engine heat. As for hot water while we travel, I've found that we rarely ever use hot water while traveling.

My coach also has the option to preheat the engine with the hydrostatic heater but Newmar doesn't make this part of the all-electric coach and I don't remember seeing it offered either. Newmar has an electric block heater for very, very cold day starts. I've yet to use it as I've avoided very cold weather camping.

[holstein13]

timjet wrote:
OK, stupid question from someone who does not own a MH yet; How do you power a residential refrig when driving down the road. Large battery bank and inverter?? Surely you don't run the generator all the time.

Mr. Mark did a good job describing his setup. Mine is a little different. We have 16 coach batteries, 8 for the house and 8 dedicated to the refrigerator and kitchen air conditioner. There is a powerful alternator on the engine that charges the batteries en-route and 600 watts of solar on the roof that helps as well. The A/C can run a few hours off the battery alone but I've never measured the exact time. The generator can be set to turn on when the battery level gets low.

In cool weather, I simply use the dash A/C but on hotter days, I'll run the kitchen air conditioner and on really hot days, I'll fire up the generator and run all three A/Cs. It's a good idea to give the generator a workout once a month anyway.

[bluwtr49]

timjet wrote:
OK, stupid question from someone who does not own a MH yet; How do you power a residential refrig when driving down the road. Large battery bank and inverter?? Surely you don't run the generator all the time.

No need for a large battery bank, just run it on the inverter and the engine generator will keep the batteries charged. One the other hand even if it was not running during the course of a day drive, probably no harm as it would still stay cool inside.