Model X Travel Trailer Consumption Analysis

[bob_p]

Did my rough spreadsheet estimate (which has been pretty accurate for predicting S P85 and S 100D trips) on an X towing a 22' Sport, based on the numbers on the forum.

While the ideal 10 hour trip is penalized about 33% (worse if an additional charging stop is needed) for towing vs. non-towing, our most frequent Houston to Austin trip would incur a 47% penalty, because without towing, we can make the trip without any charging stops, and when towing, we would have to stop once.

What this likely means is that you pay a larger penalty for towing on shorter trips than longer trips.

However... There is one advantage for charging with a travel trailer. There's the possibility of spending the charging time in your trailer - instead of the random places scattered around the superchargers (hotel lobbies, fast food/sit down restaurants, gas stations, …).

We talked to Bowlus last weekend - and haven't heard back from them in several days, with a question about storage for my wife's telescope inside the trailer.

We would like to have 300-400A of LiOn batteries - to provide power in locations where we can't hook up the trailer, such as charging stops. And we want a cellular booster to provide better cell phone signal inside the trailer. The LiOn batteries are included with the Limited Edition Road Chief - and both Road Chief editions have the cellular booster.

We also heard about a mod that can be installed in the Sport's Dometic A/C unit to reduce the surge - and make it run better off batteries.

Clearly the Sport is significantly less expensive than the Road Chiefs. The Road Chief gets better mileage, though it's unclear how much impact that would actually have on real road trips. And the Limited Edition already has most of the features we would want in a travel trailer, though we would seriously look at adding a convection microwave and TV (like in the Sport).

Not sure if we'll make a decision now - or wait until we can see a Road Chief in person in late September when we're visiting LA...

 

[idoco]

There's the possibility of spending the charging time in your trailer - instead of the random places scattered around the superchargers (hotel lobbies, fast food/sit down restaurants, gas stations, …).

We do that all the time.

...a question about storage for my wife's telescope inside the trailer.

What are the dimensions? I can check in my trailer. It might fit under the starboard bed. Or you can secure it to the lashing system, either suspended or on the floor.

We would like to have 300-400A of LiOn batteries - to provide power in locations where we can't hook up the trailer, such as charging stops.

Are you planning on using the A/C or microwave on the charging stops? On a short charging stop it would probably take more than 30 minutes to cool the trailer,

...seriously look at adding a convection microwave and TV (like in the Sport).

We thought about the same thing but decided against it. Size wise I'm sure you could swap one. But venting could be a real problem.

I would ask Geneva or Helena at Bowlus about that. Knowing how much thought they put into the design I'm sure there is a reason they did not put one in.

Also take a look at this Airstream thread on the same topic.
Microwave/Convection Oven - Vent needed? - Airstream Forums

Another possibility would be this:
Bake Your Own Bread! Are You Nuts? – Our Coleman Camp Oven - Landcruising Adventure

Or a large, electric toaster over.

 

[bob_p]

The telescope's dimension is roughly 31” H x17” W x11” D. We would likely add a little on the W & D to add some padding around it when standing in the closet. The 22' Sport's closet is relatively large and also doesn't require using space for solar panels or the awning - and should be able to fit the telescope plus leave quite a bit of room for clothing or other items.

The Airstreams have been using a Cuisinart CMW-200 with a trim kit for a built-in like you would do in a cabinet at home, allowing for ventilation through the front. When we asked about having a convection microwave in the Road Chief, it sounded like they had some concerns about the glass door not being tempered glass, though with Airstream using this for several years, doesn't appear to be much of a risk - and if we bought a Bowlus, would likely be something we would look at as a replacement for the microwave included with the Road Chief.

Good point on A/C during short stops - it is unreasonable to expect it will cool down quickly - and perhaps the best we could do during a short stop would be to rely on fan circulation. Though even if the A/C couldn't cool the cabin down completely, even some cool air might be welcome, plus the vents are directional...

The last e-mail exchange with Bowlus was asking for confirmation on the ability for us to store the telescope - and to get us a copy of the NDA they require for the Insiders program (so we could review the confidentiality terms) - we haven't heard anything from them since last Wednesday.

The Airstream provides a lot of functionality, at a much lower price, than the Road Chiefs. Though when we walked through a 22' Sport last weekend, there were areas where the workmanship could use some improvement - and at the higher price and lower volume, I'd except the Road Chiefs to be of higher construction quality.

We're going to Austin this weekend and will likely scout out some RV parks in the "dark zone" away from the Austin light pollution. Until we retire, we'd probably only use the trailer for periodic trips to Austin - and would likely only purchase a travel trailer now if we thought there was enough benefit in towing a trailer to justify the extra travel time.

 

[bob_p]

After doing our research on purchasing a travel trailer for towing with our X 100D, a few thoughts on the impact on travel times and charging:

1. Driving times with a trailer will take 36% longer due to the difference in highway speeds (75 MPH vs. 55 MPH) - this is true for towing with a Model X or with any other vehicle
2. With an X 100D, you should be able to go roughly 3 hours between charging stops while driving (under typical driving conditions), when towing or not towing; this time will be shorter due to elevation changes, head winds, rain/snow, heavy traffic, … [this assumes relatively aerodynamic trailers - with energy consumption of 600 Wh/mi or less]
3. With a trailer, charging stops may be longer if the trailer must be unhitched and rehitched (10-15 min?)
4. If the trip time is long (8 to 10 hours per day, multiple charging stops), with the combination of the above factors, the distance travelled while towing will be roughly 40% less
5. The impact will be larger on shorter drives, especially if the X could make the trip without having to stop for charging without a trailer; due to the combination of the slower speed and extra charging stop, the travel time penalty for towing could be 60-80%
6. Assuming 32A of charging from an RV park's 14-50 outlet, 12 hours of charging will add about 84KWh of charge. Even if Tesla offered a larger battery pack, you would not be able to fully recharge it overnight at an RV park - it would require finding an 80A HPWC or supercharger to get the pack fully charged before starting the next drive. [Home overnight charging of a larger battery pack would require a 100A circuit to support 72A charging on an HPWC; which could be expensive to add for most existing homes.]

Of course these are very rough numbers, and specific trips will be different. Though for those looking at purchasing a travel trailer for the first time, the above guidelines should provide an insight on the impact of towing on road trips.

 

[idoco]

The telescope's dimension is roughly 31” H x17” W x11” D. We would likely add a little on the W & D to add some padding around it when standing in the closet.

The closet is 15" wide. The total depth is over 2 feet. But because of the curve of the back wall the height differs.

At the front it is over 4 feet. At a depth of 20 inches it is around 3 feet. So plenty of room in the closet.

Only problem might be the closet opening. The opening itself is just under 11 inches. But the door opened to the max is about 10.5 inches to the door edge.

Under the bed might fit. But harder to measure. Might want to use a mock up to see if it fits there.

 

[bob_p]

The closet is 15" wide. The total depth is over 2 feet. But because of the curve of the back wall the height differs.

At the front it is over 4 feet. At a depth of 20 inches it is around 3 feet. So plenty of room in the closet.

Only problem might be the closet opening. The opening itself is just under 11 inches. But the door opened to the max is about 10.5 inches to the door edge.

Under the bed might fit. But harder to measure. Might want to use a mock up to see if it fits there.

The 11" D is only at the very bottom, so it might be possible to angle the telescope into the closet, but it does sound like a tight fit if the door opening is less than 11". And while the closet may hold the telescope, it will consume most of the available space. The closet in the sport is considerably wider (don't recall if my wife measured it), and the closet is tall enough, there's even a shelf across the entire top of the closet. So we would have considerably more space to store the telescope, along with other items.

But, it does appear we could get the telescope into the Bowlus closet...

Assuming we don't store anything else in the closet - is there enough storage space left inside to store a reasonable amount of clothing and other items for an extended road trip?

 

[ohmman]

Assuming 32A of charging from an RV park's 14-50 outlet, 12 hours of charging will add about 84KWh of charge. Even if Tesla offered a larger battery pack, you would not be able to fully recharge it overnight at an RV park - it would require finding an 80A HPWC or supercharger to get the pack fully charged before starting the next drive. [Home overnight charging of a larger battery pack would require a 100A circuit to support 72A charging on an HPWC; which could be expensive to add for most existing homes.]

It's worth noting that you're not likely to be fully drained on your existing pack and that most RV stops are generally longer than 12 hours. A 12 hour stop would be arriving at 7pm and leaving at 7am. That's more of an in-transit long driving day kind of stop. We typically arrive around 4pm and don't depart until 8am.

You can also charge at a higher current than 32A on a 14-50 in some cases, up to 40A. But at RV parks, I've heard about issues with the breakers handling sustained draw, so we do crank it down. Also, while the pedestals have separate breakers for the 30A and 50A connections, I understand that on the back end, they may be intended to supply a maximum of 40A to the entire pedestal. Since we have our camper plugged in as well as the car, I find it safest to lower the draw as you indicate.

Regarding storage in the 22 Sport, everyone likes to pack differently. We no longer hang clothing in the closet. Instead, we stack plastic sterilite bins with clothing for each member of the family, and one for dirty laundry. Under the bed goes things that aren't accessed as readily - your telescope might qualify for that. There is the storage under the benches (shoes, first aid kits, etc), and we keep one bin of pantry items in the shower.

Wouldn't the telescope be best stored in the Model X?

 

[bob_p]

When we have the trailer parked, we want to store the telescope inside the X - and not drive it around with us (especially since there is limited covered cargo space inside the X).

On the charging, for planning purposes, it appears fairly safe to assume you'll have 32A for EV charging, though you might be able to get more. And as far as charging between 4PM to 8AM (leaving about 8 hours during the day for travelling), at least for our travel planning, we'd likely be more conservative - and allocate more time for travel, and count on less time for charging - giving us some cushion for extra charging, if needed to reach a far away Supercharger.

All good feedback!!!

 

[idoco]

Assuming we don't store anything else in the closet - is there enough storage space left inside to store a reasonable amount of clothing and other items for an extended road trip?

Some folded clothing. But I doubt hanging clothes with the telescope in there.

Besides usual storage space another option is to put it on the bed when traveling and remove it when you get to the destination.

 

[JimVandegriff]

On the charging, for planning purposes, it appears fairly safe to assume you'll have 32A for EV charging, though you might be able to get more.

All good feedback!!!

Illijana and I damp down the 50 amp circuits at campgrounds to 28 amps when charging the X when we are also powering the trailer with the 30 amp circuit. We do this after having blown a circuit breaker on an underpowered box in a campground. Since using the 28 amp method dialed down in the X, we have not had a problem. My guess is that 32 amps would probably be fine, but after meeting a campground owner who had bad experiences with Tesla owners blowing his circuits, we are doubly cautious. We have never had a problem fully charging the vehicle (to 100%) overnight. I'm excited for your upcoming choices and adventures, and I'm glad you are bringing a telescope! Jim

 

[ecarfan]

Illijana and I damp down the 50 amp circuits at campgrounds to 28 amps when charging the X when we are also powering the trailer with the 30 amp circuit. We do this after having blown a circuit breaker on an underpowered box in a campground. Since using the 28 amp method dialed down in the X, we have not had a problem. My guess is that 32 amps would probably be fine, but after meeting a campground owner who had bad experiences with Tesla owners blowing his circuits, we are doubly cautious

I am also cautious in that regard. My practice is when charging the X overnight at a campground I unplug the trailer and limit the car charging to 28A from the TT-30 outlet and 38A from the NEMA 14-50. With the trailer unplugged I cannot accidentally trip a breaker by, for example, operating the trailer microwave or my induction cooktop while charging.

 

[idoco]

Usually if you are at a campsite for more than one night the max current draw isn't a big problem. There is plenty of time to charge to full, even at a reduced rate.

For the occasional time we've been short on time we'll unplug the trailer at night and run on just batteries. That way we can turn up the Tesla charging to the 32-40 amps if the circuit supports it.

 

[ecarfan]

@idoco I’m just curious if you have been on any new trailer trips this summer and what kind of Wh/mi numbers you are seeing in various situations.

 

[idoco]

@idoco I’m just curious if you have been on any new trailer trips this summer and what kind of Wh/mi numbers you are seeing in various situations.

We went to Rhode Island (492 wH/mi) and back (525 wH/mi). A slightly higher consumption than on our trip cross country. The difference being I could go faster as a result of the higher density of superchargers in the Northeast corridor.

One other short <100 mile trip after that. Don't remember the consumption since I knew 100 miles one way was not going to be a problem.

 

[felixculpas]

Great thread. Considering for a couple years out. Have done Canada east to west hauling a small trailer many years ago with a truck and interested in getting back into it in at some point. I think a Sport22FB and an X100D would be of more value than a Bowlus and an X75D if that was a budget consideration. I'd consider 2 days / campsite so no worries about charging. Though if a truck was slated for 2021 I'd be all over that. Hopefully fires don't continue to increase in number over the years. Thanks to those that have shown all the numbers.

 

[bob_p]

That's an interesting idea, for anyone considering purchase of both an X and a trailer...

Though the cost of a new Sport 22FB and X 100D will be quite a bit less than the combined cost of the entry Road Chief and an X 75D.

For those of us already owning an X 100D, and looking for a trailer option - the 2.4X price difference between the Sport and Road Chief is pretty large... And for anyone that wants the extra features in the Bowlus Endless Highways Edition (4KWh LiOn batteries, …) - it's a 3.8X difference...

 

[felixculpas]

Tesla should make the powerwall portable so you can take it from your home to your RV and allow it to also range extend your X.

 

[ecarfan]

We went to Rhode Island (492 wH/mi) and back (525 wH/mi). A slightly higher consumption than on our trip cross country. The difference being I could go faster as a result of the higher density of superchargers in the Northeast corridor.

Can you give a sense of your average speed during that trip?

 

[ecarfan]

Just a comment; it would be helpful if this thread could stay focused on the topic, which is energy consumption when towing various kinds of trailers. Please keep in mind that if someone is trying to decide which trailer to buy to tow with their X they can start a thread about that. I recognize that part of that decision is evaluating energy consumption differences between trailers, but that is only one part of the decision, there are always many other factors; price, size, internal layout, trailer manufacturer reputation, hitch type, etc.

Thanks! Carry on...

 

[idoco]

Can you give a sense of your average speed during that trip?

Trip included half highway and half local roads. Overall avg was 50 mph with highway max speed of 64 mph.