Pebble’s Electric Travel Trailer Can Hitch And Propel Itself

The electric car revolution is well underway, but soon we’ll also see the rise of the electric RV. One early entry is the Pebble travel trailer, which features a car-sized battery and electric motors on the wheels, plus all electric appliances and an attention to efficiency, at least when it ships.

The Pebble checks many of the boxes I outlined in my 2019 article outlining the future of the electric RV. In particular, thanks to its large battery and motors it can, in theory, propel itself, meaning that it could be towed without as much effort, and without draining the battery of an electric tow vehicle. One of the few things that EVs can’t do well is tow. A typical EV, even a truck like the Ford F150 Lightning, will have its range cut in half towing even a modest trailer. That happens with gasoline tow vehicles too, and many report having their gas mileage cut in half or worse when they tow, but with gasoline it just means spending a ton of money and stopping frequently for fill-ups.

With EVs, they get a lot of their range from being more efficient than gasoline vehicles, and so when you stick a heavy, non-aerodynamic trailer on the back, it costs them more. And their ranges are designed to still make road trips practical with one or perhaps 2 fast charges on heavy driving days. Change it to needing 3 or 4 and it’s an inferior experience, and certain rural areas—the very places you go in an RV—become problematic, at least until the charging networks get built out. (On the plus side, RV parks tend to have the power needed to refill overnight.)

There’s no easy solution for this problem. You would have to fill the tow vehicle with a huge, heavy, expensive battery, or hope for new, superior battery technology to come. You can do something if you make the trailer easier to tow. That can be done by making the trailer lighter and more aerodynamic, but that only goes so far. If the trailer can propel itself, that can make the difference, though today, for safety reasons, that may take some regulatory adaptation. In theory you could make a trailer you could tow with a bicycle, because it would do most of the work of moving itself, though working to never do so much as to start pushing that tow vehicle. Another issue is that if the trailer does this, it may be out of battery when the day is done. That’s OK at an RV park or if there’s fast charging, but not OK for “boondocking”—camping off the grid.

Pebble reports that while a Rivian towing a trailer gets from 0.8 to 1.2 miles/kWh, they deliver 1.4 miles/kWh without any towing assist, and 1.8 miles/kWh with tow assist working. (Not towing, the vehicles gets 2.6 miles/kWH at 55mph, while a sedan might do 4 miles/kWh not towing.)

The Pebble needs its battery because it’s all electric inside. Heating, cooling, cooking, the fridge, hot water and more are driven from the battery. A few other trailers are going mostly-electric, and all-electric compressor fridges are becoming common as solar panels can provide enough to run them, but heating is another story, and propane remains the solution there, unless you have a giant battery like the Pebble. Solar panels are a must, and with the big battery they can let campers bookdock for extended periods, as long as they don’t want to do a lot of heating and AC. The fridge, hot water and other electric needs can be kept modest.

The motors in the Pebble also let it move around on its own, unhitched, and even better, automate the process of hitching it up and unhitching. Rather than deal with the complexity of backing up with a trailer to put it in a small campsite, owners will be able to just stop, undo some latches and chains and have the Pebble unhitch itself. They they can drive it like an RC car where they want it to go, and reverse that when they want to leave. It should reduce one of the bigger hassles of trailer camping.

Some of the Pebble’s efficiency comes from aerodynamic design—they claim it’s 3 times as aerodynamic as some trailers. One neat trick is that the plastic nose which covers the front (there are no propane tanks of course) is designed to lift up high during travel. Most trailers are badly designed, and have a curved front, in particular the famous “teardrop” designs that want to be the most efficient. A teardrop is the most efficient shape if the trailer were driving without a tow vehicle, but in reality what matters is the drag on the combination of tow vehicle and trailer. The low front teardrops create a vortex between the back of the tow vehicle and the front of the trailer, actually making drag worse!

The Pebble is far from cheap at $109,000. That’s much more than most trailers of this size, though not too far from higher-end brands like Airstream, so there will be customers. For those who want to tow with an EV, a vehicle like this may be the only option. In addition, if one plans to put 50,000 miles on a trailer, then an EV and EV trailer can save a lot of money spent on gasoline, which could reduce the total cost of ownership quite a bit. Many RV voyagers report around 10mpg, so 50,000 miles is $20,000 at $4/gallon. The electricity might be just 1/3rd of that. In time, the electric RV could end up cheaper in total cost.