Published on May 18th, 2019 | by Maarten Vinkhuyzen0
Volkswagen MEB Platform = Mistakes, Errors, Blunders? Or Masterly Engineering Brilliance?
May 18th, 2019 by Maarten Vinkhuyzen
Without ambition, you go nowhere. Let that be clear. Volkswagen is showing a lot of ambition, what is very great.
To conquer the fully electric vehicle market, you can’t build an electric vehicle from scratch and think that is the car you are going to conquer the world with. A single ad-hoc project, like the Chevy Bolt, is not the way to create a growing presence in the electric vehicle market.
You need to get experience, and you need to be able to build a lot of different vehicles without starting from scratch every time, collecting the lessons learned into a set of best practices and standardized building blocks to facilitate the design of future models. Using standardized building blocks will lower the costs of cars significantly.
Volkswagen has a lot of experience designing cars and it has very successfully used that experience to create sets of building blocks that are used by all the brands of the Volkswagen Group. This use of a set of standardized building blocks across all brands in the Group is in large part responsible for the success of Volkswagen Group in recent years.
Volkswagen Group decided in around 2015 to build a dedicated set of building blocks for the battery electric vehicle (BEV) market, known as the MEB (Modularer Elektrobaukasten or Modular Electric Building-blocks). There are too many large and small differences from fossil fuel vehicles to use a shared or adapted set of building blocks, but BEVs provide this opportunity. It is the smart thing to do, and VW will get a lot of advantage from this exercise. There is an excellent discussion of the MEB on Jalopnik (which is a rather colorful/opinionated gearhead blog).
What is not so smart is building this MEB, an investment of probably a few billion euros, before VW had much experience making electric cars or understanding this new developing market. What is even less smart is to declare that the set of building blocks is cast in stone until 2025. A new model designed in 2023–2024, that should be in production for 6–8 years until the early 2030s, has to be designed within the parameters set around 2015. This is really not smart.
It is a logical mistake for managers working in the internal combustion engine industry. They have a clear idea what the parameters and requirements of those engines will be in 2030. Realizing in 2015 that they have no notion what the requirements will be in 2020 when the first model based on the MEB will hit the market was just outside their scope.
This year and in the next few years VW will surely encounter many lessons. What VW needs is an adaptable MEB that can incorporate these lessons learned. This first MEB is in many ways a proof of concept. As such, it is great. If management refuses to incorporate the experience it gain in these years, the MEB will be known as Mistakes, Errors, Blunders.
The models VW intends to build on this MEB platform include C-segment and D-segment cars, CUVs, and SUVs. For an auto to be successful as a BEV, there are three really important aspects. To reiterate what has been mentioned countless times on the pages of this site, those aspects concern range, charging speed, and charging infrastructure.
The charging infrastructure is not part of the MEB platform and is being built by VW and its partners. There is no problem with this aspect of the ecosystem.
That leaves range and charging speed as possible core problems, besides many smaller potential design flaws or missed opportunities.
Putting the potential range in a table for the intended vehicle categories.
As the market’s experience of 7 years with the Nissan Leaf and Renault Zoe has shown, 45kWh is just not enough for mass market appeal. It could be an attractive option to have on the C-segment cars, but mostly to sell the larger battery. On less aerodynamic and heavier or bigger models, it is just not enough.
The 58kWh battery is great for the C-segment, if it is an efficient aerodynamic design. When thinking SUVs or the larger D-segment, it places serious constraints on the designers. Tesla did show with the Model 3 that it is possible, but are those constraints acceptable to designers 5 years from now? I doubt that. As Jaguar, Audi, and Mercedes-Benz showed, D-CUVs and D-SUVs need a lot more than 58kWh. Over 80kWh is not enough unless you have Tesla or Hyundai expertise in making a body that gets every potential mile of range from your battery.
The 77kWh option is a winner for C-segment cars and likely ample for C-CUVs and C-SUVs, if they are designed with aerodynamics and range in mind. For the D-cars, it does not put unmanageable strain on the designers.
What is clearly missing are 100kWh and 125kWh options. Perhaps not for this year, but surely for 2022. Luckily this is the one aspect of the MEB that is likely to see new building blocks form as better batteries become available.
Looking at the charging speed (or power, to be technical), 100kW for the 45kWh and 58kWh batteries and even 125kW for the 77kWh was a lot in 2015, when the Zoe and Leaf were struggling to get to 50kW. It is not good enough when new cars reach dealers in 2020. It is less than half what is needed before this platform reaches its planned end of life. To have higher charging rates, there is more to change than just the battery. Power electronics, wiring, BMS have to be upgraded too. Some stone has to crumble to loosen these blocks.
When we go beyond the main aspects of a successful electric car, we see a number of design decisions that are spot on, and some that are made too early.
Using a flat skateboard design with the wheels pushed to the corners of the car is the right way to do it. That creates maximum internal space for the passengers while still allowing for large enough crumple zones.
Enabling both rear-wheel drive and all-wheel drive is another simple and effective design decision that makes the set of building blocks very useful for a lot of different cars.
Only two motors are used for the platform, a 150–200pk rear-wheel motor and a 50–100pk front-wheel motor. Volkswagen can give them different characteristics via software and different gearboxes. This minimizes costs while maximizing flexibility. If they follow the example of Tesla, that can mean 10–20% improvements via software updates when they better understand their powertrains. Whether or not this is enough power for the larger SUVs and CUVs later in the next decade is a big question mark, though. Likely, a big mallet and chisel will be needed in that time.
The motors and batteries are liquid cooled. This is again the right design decision. Whether the cooling system will blow away teardown experts like Sandy Munro is not important. The health of the battery is what’s important.
Using extra-large wheels (18″ and 21″) to create the extra ground clearance needed for the battery pack is a nice optical solution for the thick floor a skateboard design creates.
Because of the needs of the battery while charging, the cooling is probably not good enough to last until the end of next decade. Faster and more efficient charging and prolonging battery life with more control over battery temperature is needed. Using large cells gives a small cooling surface. It is good enough for normal driving and will prevent the problems that batteries without liquid cooling experience in extreme circumstances. However, it is not good enough for faster charging or more demanding driving.
Electric motors are not really a new innovation, they have been around for a really long time. The use in EVs asks different capabilities than previous use cases. There is fast development around a special type of electric motor for EVs. The current motors in the MEB won’t be state of the art in 3–4 years.
When not crippled by wrong directives from the marketing and product development gurus, the MEB created by the VW engineers could stand for Masterly Engineering Brilliance. It seems the barrier right now is just that there are rigid directives by managers who don’t yet realize that the static world of fossil fuel vehicles is a thing of the past.
Tesla applies new insights on a weekly basis to its cars. The VW managers have frozen progress for the next 7 years after validating the MEB platform. In the current disrupted environment, adaptability should have been the #1 design parameter for the MEB platform. No part of this platform can stay unchanged for the next 7 years.
For the arrogance of the managers, I think this MEB platform will become known as Mistakes, Errors, and Blunders. That is, unless those managers are able to put mallets and chisels in their toolboxes. How fast will they realize they need a new platform by 2022?