Is an all electric TaB trailer viable

CharlieRN

Thanks for the added photos @Viajero, the last couple were particularly enjoyable. Somewhat less enjoyable were the pictures showing you charging. The photos demonstrate that the Tesla charging network is far superior to the others presently available, and that they are likely to be less crowded. They also show the need for more pull-through stations!

Ironically, we are seriously considering moving to the 400. We love our 320 and have upgraded it considerably, but it's quite cramped with our two Welsh Springers (see photo below, with T@B in background.) It would also be nice to be able to leave the bed in place and still have a place to sit, relax and eat, as well as having a less claustrophobic toilet/shower area.

We travel at 55 - 60 mph, in the same 90 kph neighborhood as you. I 'm really hoping that we see similar efficiency from the Rivian, and that its larger battery pack (135 kWh vs either 75 or 60 for your Model X (apparently some X's are software-limited to 60 kWh) will give us a bit more range. The Rivian is much heavier than your Tesla however, and not as aerodynamically slippery, so that will work to reduce things a bit.

I'll also mention that my Rivian reservation (made in May of 2020) is actually for the R1T pickup truck with the 180 kWh "Max" battery pack. At present, that's the only model the larger battery pack is available on, but Rivan had consistently delayed delivery. We have an estimated delivery window of 1H2023, but there have been reports that the Max will be delayed again, until at least 2024, perhaps even 2025. If that turns out to be the case, we would change to the SUV, the R1S, with it's smaller 135 kWh battery. We really prefer the SUV, and with two dogs it's far more practical, but range anxiety has been pushing us toward the R1T Max. Your experience towing gives us a good indication that our range loss will be a lot less than the 50% we'd been anticipating, and makes us more comfortable about the viability of the SUV and its smaller battery as our TV.

Thanks again.

Viajero

Glad I could help. 

Oh, and our Tesla is a model Y. 👍

AnOldUR

CharlieRN said:

Ironically, we are seriously considering moving to the 400. ... It would also be nice to be able to leave the bed in place and still have a place to sit, relax and eat, as well as having a less claustrophobic toilet/shower area.

Although we don't see a 400 in our future, we have the same thoughts as you. Some of the downside of a 320 can't be modded away. Even so, the bigger footprint that comes with a larger trailer is not worth the advantages to us. Selfishly hoping that you stick with what you have. Always enjoy reading what you add to the 320 conversations here on the forum.

CharlieRN

Viajero said:

Glad I could help. 

Oh, and our Tesla is a model Y. 👍

Apologies for the model mix up. In my defense, the letters are next to each other on the keyboard . . .

Denny16

Charlie, unless you need a truck bed, the SUV version makes more sense.  I wouldn’t get too stressed out over the lower power battery and slightly reduced range.  With new charging stations and upgrades happening all the time, charging should not be a major issue In the next year or two.  Adding and I,proving charging stations has become a federal priority lately, with the new infrastructure bill.  I think we are going to see quite a few changes in this area.
 Cheers 

CharlieRN

Appreciate the feedback @Denny16. I've never owned a pickup, rarely have the need for a truck bed and so absolutely agree with you that the SUV makes more sense. The slightly smaller size of the R1S vs the pickup is actually another advantage since we are often in nearby Phila.

I'm gradually becoming more comfortable about towing with the "small" 135kWh battery (somewhat confusingly called the Large Pack) as I see more real-world results from Rivian owners and from those like @Viajero who successfully tow with vehicles that have much smaller batteries. Of course, the Tesla folks have the huge benefit of an existing fast-charge network that is both widespread and reliable. As you note however, the charging infrastructure in general is improving at a pretty rapid pace.

As my post above indicates, I'm waiting to see what Rivian does with their 180 kWh Max battery pack. One reason I'm reluctant to give up on it is that I'm grandfathered in at a price that is well below the current MSRP. So if it didn't work out with the R1T, I should be able to trade or otherwise dispose of it without the usual financial penalty. I'm also interested to see what happens with Kia and the new EV9. It looks to be about the same size as the R1S, though with a bit less towing capacity (but still more than enough for a T@B) and less off-road capability. OTOH, it has 800v charging architecture and will likely cost 30% less than the Rivian.

pthomas745

Well, obviously, the chargers under the water tower are....hydro-electric!

Denny16

Charlie, Andrew Ditton, a UK Caravan ambassador, tows a TaB size caravan (trailer) with a similar EV to the Kia EV9 and made it from Scotland to Germany without any issues.  See his UTube channel for details.  

It woun’t be long before Tesla’s charging network is opened to non Tesla EVs.
 Cheers 

Viajero

Denny16 said:

Charlie, Andrew Ditton, a UK Caravan ambassador, tows a TaB size caravan (trailer) with a similar EV to the Kia EV9 and made it from Scotland to Germany without any issues.  See his UTube channel for details.  

It woun’t be long before Tesla’s charging network is opened to non Tesla EVs.
 Cheers 

I wouldn’t count on the existing supercharger network being opened anytime soon. Tesla is getting paid to add CCS cables to new V4 installations, none of which have been built yet. The existing V2 and V3 stations would be difficult to modify and under the current federal program spec guidelines none would qualify for the existing money. It will take a while. 

JamesK

Denny16 said:

With the 2023 TaB coming with a large lithium battery upgrade available, like the 400 amp hr battery with a 3KW inverter/charger package for the TaB400, and large 2-way fridge, can we expect an all electric TaB (no propane systems) in the near future?  

But how long could you expect to run either one just off the 400 amp hr battery bank and having  almost 400-watts of solar available (190-watts on roof snd a 200 watt portable panel setup).  Add in an induction cooker in the galley.  

Seems like a nice plan, but will it work for an average three days off grid camping trip?

I guess one way to get a feel for this is to convert everything to propane.

Simplifying the discharge curve of a LiFePO4 battery to a flat 13V:

400 AH 13v battery   =   18,720,000 Joules of energy
5 gallons of propane = 482,690,000 Joules of energy

18,720,000 divided by 482,690,000 = 3.8%

So the 400 AH battery is the same as having a 5 gallon propane tank that is 3.8% full.  Ignoring the air conditioning, I would ask how many days you typically expect to be able to cook, heat, shower, and run a 3-way fridge from a full propane tank and then divide that by 26.

The 400 watts of solar, from my experience, might produce 150 amp hours at 12v (simplifying) = 6,480,000 Joules = 1.3% of a propane tank per day.  I think that is probably over-estimating the solar given the fixed position of half of it.

Using the AC consumes about 450 watts = 1,620,000 Joules per hour = 0.33% of a tank of propane per hour.

My golden rule is never to post anything involving math after midnight, but I think the numbers are correct.

Denny16

Interesting analogy James, but running everything less AC and cabin heat is very doable on 400 amp/hr lithium.  It’s the heating and AC that sure energy esters.  

Our 200 amp/hr AGM keeps the two-way fridge and lights going for three to four days of camping.  A 400 amp/hr lithium would give the extra energy needed for cooking, using a microwave and convection stove top burner.  Most of our camp cooking is reheating pre-cooked meals, and some light cooking on the road.  

Cheers 

Grumpy_G

Fun fact: A 5 gallon propane tank packs almost 135 kW/h of energy. Granted fossil fuels do not convert anywhere close to 100% but compare that to the size and weight of a 100 kW/h Tesla battery. Energy density of current battery technology is abysmal compared to fossil fuels. 

Denny16

Maybe so Grumpy, but we need to start to move away from fossil fuels, where we do not really need them, like 3-way fridges, where a 2-way compressor fridge is more efficient.  Propane doesn’t do air conditioning very efficiently either, so it’s main application is heating, both cabin and cooking, where it is more efficient right now than electrical based systems.  

That said, I do not like the fire risk inside the TaB from a propane stove, and for the small amount of cooking I do in thenTaB, a induction cooktop would suffice.  Outdoors, a small gas grill is another grand alternative, so like it or no, we currently need propane for heating…
Cheers

AnOldUR

Denny16 said:

... a induction cooktop would suffice ...

Damn you @Denny16, another mod I have to look into.

tphaggerty

So there were comments about the T@B not being well insulated, which may be true, but my wife and I have had our 2018 out in 10 f weather for several days with no problems, nice and cozy. We did dry camp (no water, no toilet- although I would use the toilet with water jugs if needed). And we did have some moisture issues, but we were able to crack the windows and vent and reduce the issue with practice. Nothing that a quick wipe with a dry towel wouldn’t fix anyway.

As to a full electric T@B, I think they are too small to have enough battery plus a large inverter to be able to handle a large load like the heat pump (AC or heating) for any real length of time. I have 350W of rooftop solar (2 175W Renogy flexible panels) plus a 100W portable and I’m still adding another battery (to total 300 ah) because solar doesn’t do much in shady NE campgrounds and we often do 10+ day trips. That’s mainly to power our 2 way fridge plus lights and water pump, we don’t need to run the heater until nights get into the 40s.

Check out the Winnebago Ekko class C to see a full electric 4 season RV. Something like 13kw of battery (vs 3.6kw for my 300ah batteries). You can option even more power, the main non-grid charging is by a dedicated 2nd alternator. I think the electrical components would probably fill half of my 400 just by themselves (plus it is something like 150k msrp).

bergger

 We got a chance to get inside an Ekko a few weeks ago at the Overland Expo Mountain West event.  Very impressed with it and would love to tour around in it.  

Viajero

Keep it simple. But a standard T@B 400, keep the Alde for heat and water and get the cool top charged out for an induction unit. 

Tow the whole thing with the electric vehicle of your choice that has on board inverter so you can plug in the T@B.  Easy peasy. 

bergger

I saw this online the other day.  Beautiful trailer and interesting how long and well it can run on electricity.  With 1360 watts of solar and 810ah of battery it's off to a good start. The price is hard to swallow though! Out of curiosity I emailed them with a few questions reference the insulation and the efficiency of the two 500 watt toe kick heaters.

https://coast.aerobuild.co/

Denny16

Interesting @bergger, the specs state the insulation is: “ Thanks to Havelock Wool Insulation, Coast stays cool in the summer and warm in the winter, keeping your cabin operating at peak efficiency.”  Also with a 49” wide main bunk and a 42” dinette berth, not too many folks are going to find that comfortable sleeping two in a small bunk.
 Cheers 

bergger

Yeah I'm curious to see what they say about the insulation of the trailer.  Never heard of a trailer with wool insulation before.  Maybe the narrow bed is another way to stay warm!    We've always slept in a full bed at home and in a 48" bed in our truck when we camp out of that.  A 49" would be fine for us.  I really like the layout and look of the trailer.  I'm really interested to find out the power consumption of the two toe kick heaters and if the system can really work well in sustained cold temps.  Nice to see an attempt at an all electric trailer.   I think the price is going to keep it out of the reach of most people. 

SLJ

My 2021 T@B walls are pretty insulated not including windows and door. Don't know what's in the roof. Here's a section I cut out.

 

Denny16

The roof is an aluminum frame with the same insulation in between the frame members under the aluminum roof and interior ceiling (I believe there is a layer of Reflectix like layer under the aluminum).  There is some thermal transfer through the roof where the frame is close to the aluminum top. (Edit: the Reflectix layer helps reduce this) which is transferred to the interior ceiling.  The TaB windows  are double acrylic panes with trapped air, which adds a thermal barrier.  The door window is single pane, but has an insulated/reflective shade to help add some insulation here.
 Cheers 

Sharon_is_SAM

The exterior roof skin is very thin aluminum, then a layer of bubble insulation (like Reflectix), then the aluminum cage frame with  foam block insulation.  The inside ceiling is a 1/8 in ply covered with a thin, faux birch veneer. 

Found this from a previous post.

How are your trailers insulated 

Created by: Michael Skidmore 

Modified on: Thu, 24 Oct, 2019 at 8:47 AM

---

How are your trailers insulated

For the Tab/Tag/Cirrus- The R-value of the cut insulation we place between the rafters is rated as a 3.6. We use a foiled double bubble, which lays on top. Unlike traditional insulation this product is not rated by an R-value. Bubble insulation is rated by it's reflectivity and emissivity. R-values are based on thermal resistance (how long heat takes to pass through the product), the thicker it is the higher the R-value. Bubble insulation is very thin, 1/8", but has a high reflectivity, 96%, and a low emissivity, 4%. Only 4% of radiant heat passes through the insulation, we are not trying to slow the way heat passes through the insulation but trying to slow the way heat passes through the insulation but trying to eliminate heat from passing through it. The R-value of the Azdel and block insulation combination is rated as a 4.5

Denny16

Thanks Sharon on the roof insulation details, great info in your post.  I do believe from what I have read about using Reflectix or similar bubble reflective material, it really helps reduce thermal loss or heat/cold transfer between the frame and roof aluminum skin. 

I remember someone posted a photo showing the thermal transfer on the roof (shot from inside) and you can see where the frames are, which are transferring more heat than between the frames where the extra foam based insulation layer is.

The Reflectix is amazing stuff, doesn’t look like much but it works.  The other day the temps dropped to around 29-30F and was still 30F at 8am.  The windshield on the cars were frozen, but my Jeep windshield was just a little wet, as I had put a Reflectix shield inside the windshield the previous day when the sun was out.  The Reflectix reflected enough heat from the morning sun, it had melted the thin ice layer, whilst the other vehicles windshields were had a frozen layer of moisture on them.
 Cheers 

Mickerly

I don't think much sun comes through the aluminum skin.

Sharon_is_SAM

Well, I can tell you that camped at Assateague Island National Seashore in the blazing sun and 80 - 90+ F heat the roof is a heat sink.  Even a canopy over the top of the TaB did not help.

@Denny16 - @DougH did the thermal imaging and reported the thermal transfer via the aluminum framing.  No matter the cause, there are very real limits to our little trailers.  

DougH

Sharon_is_SAM said:

Well, I can tell you that camped at Assateague Island National Seashore in the blazing sun and 80 - 90+ F heat the roof is a heat sink.  Even a canopy over the top of the TaB did not help.

@Denny16 - @DougH did the thermal imaging and reported the thermal transfer via the aluminum framing.  No matter the cause, there are very real limits to our little trailers.

The few that I snapped a few years back was when I was improving upon the original air conditioner. That was done with a low resolution Seek microUSB camera. The aluminum ribs were always very visible when the sun beamed down on the T@B rooftop, and 10-20F warmer. You could feel where the ribs were even if you had no thermal camera.

A very nice and much more sensitive Android thermal camera is now available. When I've had cause to use it for sealing and insulating a new-to-me house in upstate NY before winter set in, I could see all the studs in the walls and joists under the floorboards. Made the house eerily almost translucent...

https://a.co/d/atecmOV

Recommended.

bergger

Yes the insulation in the T@b roof is poor at best and the overall insulation is only marginal.  But I'd call it par for the course as far as the average RV insulation goes.  

Denny16

Whilst the TaB insulation is minimal, it does equal a RH4 level, and is better than the original trailer I used to live in, which had no insulation.  It just had an aluminum skin, air gap (the only insulation) and the interior Birch ply inside walls and roof.  It would heat up under a 70 outside temp, to well over 90 inside the trailer if I left it closed up.  Needless to say, I didn’t hang out in it on warm sunny days.

The TaB does heat up when the sun shines upon it.  With 50F ambient temps during the fall, and a sunny day, the TaB did heat up to a toasty 70-75F with the window shades open and windows closed.  However, during last summer’s trip in July heat, I was able to keep the trailer cooled to 75F, with the Cool Cat set on 70F, and the TaB in the sun with 90+ outside temps.  I did use some Reflectix on the outside of the front window, when it had full sun on it, which helped. So while the insulation is minimal, it is better than none. 
 cheers