BMW is currently working on its fifth generation electric powertrain technology and it arguably represents the biggest change in electric motor and battery technology for the German automaker since the launch of the BMW i3 in 2013.
We took a closer look at their upcoming new technology this week.
Full disclosure: BMW invited us to Munich to check out their latest EV technology and electric production plan. They paid for all our travel expenses.
BMW invited a group of American and Canadian reporters, including myself, to take a trip to Munich to talk to the leaders of their electric programs and give us a better understanding of the automaker’s electrification plans.
On that front, it was a success because I did gain a much better understanding of BMW’s approach to electrification.
I will go into more details about the plan and the logic behind it as well as my take on it in a post that will follow this one soon.
But for now, this post is only about BMW’s fifth generation electric powertrain. We already knew a bit about it, but we now got a much closer look after visiting their prototyping lab in Munich and also some time with the company’s people who are developing the technology.
BMW’s fifth generation electric powertrain technology is going to enable the company’s first long-range electric vehicle.
It features more integrated, powerful, and yet compact drivetrain and battery packs with higher energy capacity.
Battery Packs, Modules, and Cells
Today, BMW’s biggest battery pack is the i3’s 33 kWh pack, but the fifth generation technology will include battery packs with more than twice the energy capacity.
The BMW iX3, which was unveiled in China earlier this year, is going to be the first vehicle to feature this new powertrain.
It was already announced that the electric SUV will feature a 70 kWh battery pack.
In the basement of a prototyping lab in one of BMW’s many facilities in Munich, the automaker showed us an “early prototype of the battery pack”, but we weren’t able to take pictures of it.
Unsurprisingly, they went with a skateboard-like platform, which has somewhat become the standard for bigger battery packs over the last few years.
They appear to still be experimenting with battery module configurations as the packs that we saw, both an iX3 pack prototype and an iNext pack prototype, looked fairly rough.
Here’s a video of BMW prototyping battery modules:
One thing is clear, the new battery modules will be made of li-ion prismatic battery cells.
I asked Stefan Juraschek, BMW’s head of electric powertrains, about the decision to go with prismatic cells.
The engineer explained that they considered cylindrical and pouch cells but they see advantages building modules for prismatic cells when it comes to things like cooling and manufacturing.
It is becoming the standard in electric vehicles from legacy automakers. Only Tesla and a few new EV startups are venturing into using cylindrical cells.
BMW is already using Samsung 94 Ah prismatic cells for the BMW i3. The automaker’s PHEV vehicles also use the prismatic cells.
While they are sticking to the prismatic format, they are experimenting with different sizes and chemistry.
For now, they are sticking to lithium-nickel-manganese-cobalt-oxide NMC. The company has expressed concerns about cobalt supply and during the tour of the lab, they briefly mentioned ambitions to reduce the use of cobalt in their battery cells.
The company expects that energy density is going to increase by about 5% per year over the next decade.
Even though BMW is buying cells from suppliers, like Samsung, the company is prototyping its own cells inside that basement in Munich:
The prototyping line is capable of making about one thousand cells per year, which is enough to make several prototype battery packs.
Juraschek explained that they want to gain an expertise in battery manufacturing and chemistry in order to work more closely with battery makers.
BMW executives often emphasized that battery cells are a critical part of the automaker’s electrification plans. But when I asked if they would make the jump to manufacturing their own cells, they said that it is a big commitment and Juraschek added that they wouldn’t want to upset their suppliers.
Electric Motors and Drivetrains
One thing that BMW has no issue bringing in-house is electric drivetrains.
For the fifth generation, BMW is moving away from permanent magnet motors and integrating the electric motor inside the drive unit to create one entire compact system.
We got a close look at this new electric drive unit, which is dubbed ‘Heat’, and it is indeed impressively compact for a 200 kW system:
Juraschek said that they can pull as much as 250 kW at peak output from this relatively small electric machine.
BMW claims to have made several innovations with this motor including with the more compact and easier to manufacture coil system seen in the pictures above.
The automaker plans to use the drive units in a variety of different powertrains from PHEV to BEV including single and dual motor configurations.
It will first make its way to the BMW iX3 in 2020, along with the previously mentioned new battery pack technology powered by the latest cells developed with the German automaker’s suppliers.
Again, this post was to focus on what we learned about BMW ‘s fifth generation electric powertrain technology. We will follow with another post about their plans for production and their overall approach to electrification as well as my thoughts on the entire situation after talking to BMW executives.
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