BMW Explains How “Pretertyping” Saved It From Building Battery-Hauling Trailer


2017 BMW i3 Battery

It saved the company from building a range-extending trailer for hauling extra EV batteries.

Automotive designers come up with lots of ideas that never hit the road, and BMW has a system called “pretertyping” as a way of testing those early shapes before even building a concept, according to Automotive News.

BMW i3 Battery – Apparently People Didn’t Like The Idea Of Shoving This In A Trailer To Tow Behind A Car

Pretertypes are paper models or sketches that BMW’s advanced research teams show to public focus groups. These are generally ideas that are still at the earliest stages. According to Automotive News, the company doesn’t even have a trademark on these shapes yet when the designers start getting feedback on the pretertypes.

Rainer Daude, the boss at BMW’s Munich-based forward-looking technology office, discussed pretertyping the idea for a battery trailer for hauling behind an EV. It didn’t go over well with the public. “Asians were polite, Europeans were more direct, but the response was the same: No one liked it,” he told Automotive News.

Pretertyping is a clever way to get very early feedback about ideas. The company’s concept for an elevated road specifically for electric scooters could have used this early evaluation. The notion didn’t make much sense because its novel solution to crowded streets was just to build more roads that only certain traffic was allowed to use.

BMW i Vision Dynamics

Many of BMW’s recent concepts have imagined futuristic EVs. For example, the Concept Link shows off an avant-garde scooter. Similarly, the i Vision Dynamics (above) presents an electric sports sedan with a 373-mile (600-kilometer) range that would be a greener alternative to the 4 Series Gran Coupe.

In terms of upcoming products, both the 8 Series Concept and Z4 Concept likely provide an accurate preview of what to expect when those models hit the road.

Source: Automotive News

Categories: BMW


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30 Comments on "BMW Explains How “Pretertyping” Saved It From Building Battery-Hauling Trailer"

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“If I had asked people what they wanted, they would have said faster horses.” — (not really) Henry Ford

Sorry for a “Grinch” post on Christmas eve, but I was hoping for more substance in this article.

“Pretertyping is a clever way to get very early feedback about ideas.”

So now there is another corporate-speak buzz word; this one to mean “asking people what they think about an idea”.

Some people actually invent new things or imagine new ideas; others just invent buzz words so they can paste a new label on a very old thing.

“The company’s concept for an elevated road specifically for electric scooters could have used this early evaluation. The notion didn’t make much sense because its novel solution to crowded streets was just to build more roads that only certain traffic was allowed to use.”

Hmmm, kinda like the Boring Co. concept, except that uses subterranean roads instead of elevated ones.

BMW is FOS……


I have never understood why the idea of a bettery trailer never took off?

1. No need to haul around massive weight on your every day commute

2. Nice home battery (powerwall)

3. Exra cargospace and range on the odd long trip. Coming to a fast charger station you could charge the trailer on one station and the car on one.


Have you ever used an ordinary car to pull a trailer?

It’s a hassle, it’s hard to back up, it makes it difficult to find a parking spot, and it’s not entirely safe. Some States, perhaps many state, have a lower speed limit on the highway when pulling a trailer.

Plus, I’m not at all convinced that a large battery pack is “unnecessary weight” for most drivers. A larger battery pack means greater capacity; and that has several advantages: Not only longer daily EV range, but also more flexibility in being able to use the car more often and for longer trips; a potential for faster en-route charging, because a larger battery pack can absorb more power without overheating; better battery life, because the pack doesn’t have to be cycled as often, and when it is cycled, doesn’t have to be cycled as deeply; and better resale value for EVs with longer ranges.

Now, someone who drives just a few miles a day in his EV probably won’t get much use out of a larger battery pack. But then, such a person could likely get by just fine with a low-speed NEV, so why would they buy a real highway-capable car anyway?

And On top of all that., It’s Ridiculosly Goofy Stupid Looking & Fugly as hell!…Yahoooooooish

Per “Have you ever used an ordinary car to pull a trailer?” Yup! I have! And in the Winter, too!

Was driving up from Kamloops, BC to Terrace, BC to go get a Motorbike left behind a a friends place. Somewhere past Smithers on the way up, some car passed and splashed mud/snow/slush on my Winddhi2, causing, somehow, me & my car & trailer to end up Sideways: 90° to the road, on a 2 lane road, down a cut/fill ravine dip in the road! Nealy went over the bank, but stopped about a yard short! Had to back up a bit, then go back up the side of th road on the wrong way side shoulder slowly to the top, and about a 1/2 a click past for safety to see traffice before turning around safely!

“Winddhi2” = ‘Windshield’ – sorry! I hit submit accidentally!

I am surprised that some DIYer hasn’t done this already. You can easily buy Leaf batteries and now also Bolt batteries. Chuck it on a trailer, and then devise an interface with the car. Not simple and definitely would require some engineering, but IMO not outside the realm of possibilities.

Other than cost, I really don’t think it is as terrible idea as others here seem to. If only the manufacturers were to coordinate with others to allow the interface, I could see a rental battery trailer business opportunity.

jehugarcia on YouTube made such trailer for its VW Samba bus EV conversion. If you want to take a look:

There you go!! I knew somebody would do it. He extended the range of his goofy bus from 70 miles to 200. What’s so dumb about that? Why carry around a big, heavy, expensive battery all the time that you only need to use once or twice a year?

Plus, if not too heavy a trailer, it could be a single swivel wheel trailer, with 2 connections to the car, for easier backing up: no jackknifing, too!

I have been thinking of making a trailer with 100 lbs total dry trailer weight, to carry 400 lbs battery weight, for > myelectricfly . com ” + “<" & spaces for link!), since Geo Metro has been fitted for towing a 500 lb trailer!

Hard part seems to get strong but light hardware for the trailer! The batteries I had planned for it were 32 or 33 Thundersky LiFeP04 160 Ah cells! Either 4 x 8 or 3 x 11 layout!

During a long trip, You could drop the trailer off at a charger while running local errands. It could have options for charging tbe main car battery or purely aux power. Love the idea of it being a home generator, powerwall substitute. And how about fully charged exchangeable trailers, rather than intrusive battery swaps?

That fully charged exchangeable trailer idea, I first saw come up back in 2011-ish time frame, or 2012-ish! I think it was in Germany! Big challenge remains: where and how to connect to use the energy While Driving! Charging Plug connections on the car are programmed so as to not allow the car to drive while plugged in!

Likely need to connect at the Motor Power side, using the Regen Circuit to pass the current, or via a whole new motor controller design: one that allows AC, DC Charging, plus DC Parallel or Boost Power, plus Motor control, & regen to main & auxiliary packs!

Any trailer has a huge negative effect on energy consumption. Try it. Then add the additional hassles, not being able to park etc. all round bad idea. Makes Rex look sensible.

Put them in a towable RV or caravan.

Is ‘pretertyping’ prototyping for preverts?

You are going to have to answer to the Coca Cola company.

Thank you Colonel Bat Guano, if that is your real name.

They’re trying to pollute our precious bodily fluids!

We cannot allow a battery trailer gap!

Why not just open a GAP store there?

They should have pretertyped the word pretertyping.


A battery trailer would be useful if it is still usable to carry things. It wont be economical if you don’t use it all the time but that could be solved with a rental service.
To make it compatible with all vehicles (including ICEs) it could have its own powertrain.
I think someone has made one that is ICE powered.

Tjat was done for the ‘T-Zero’ and also by others, as seen on evalbum . com!

AC Propulsion, who built the tZero, also made a “genset” trailer for their prototype BEV supercar. “Genset” here means a gasoline-powered engine plus generator. Kinda strange seeing photos of the tZero sitting at a gas pump because the genset trailer needed a refill for its gasoline tank!

The trailer contained no batteries, unless it was a starter battery for the engine.

BMW uses ‘pretertyping’ to gauge what’s popular and not popular in the future. Yet BMW keeps dragging out the garbage i8 year after year.

“Irony, please let me introduce you to Hypocrisy..”