What are the steps to build a car with NEDC range exceeding 700 km? Behind the scenes.

If we stand at the end of 2017, where the mainstream electric car range is generally around 300 km, it’s hard for me to imagine that the range of pure electric cars in 2020 has reached 700 km. But the fact is that Tesla and XPeng Motors have achieved it.

After seeing XPeng P7’s range breaking through 700 km, I asked my colleagues a question: If you were given a chance to make a pure electric car at the end of 2017, what type of car would you like to make and what range would you plan for?

Except for some colleagues who answered with jokes, the remaining few chose to make an SUV with a target range of 500-600 km.

However, XPeng Motors chose to make a mid-size sports sedan with a target NEDC range of 550 km. Is there a difference between this and P7’s current achievement?

Let’s start with the first story.

A big goal from XPeng Motors

The XPeng P7 project was initiated at the end of 2017. At the initial meeting, many people hoped to make an SUV.

After all, from the market’s perspective, the Chinese SUV market was in a period of rapid growth at the end of 2017. The monthly growth rate of SUV sales compared to 2016 was stable at over 10\%, and by the end of 2017, SUV sales accounted for over 44\% of total auto sales.

Moreover, without a major breakthrough in battery energy density, the battery pack of an electric car laid on the floor would take up at least 15 cm of the vehicle’s height. Making an SUV would not only provide more space for the battery, but also more space for the passenger compartment. The abundance of space in the height of the SUV greatly reduces the impact of the battery on the interior space of the car, and also reduces the technological threshold to a great extent.

Simply put:

  • NIO’s first car ES8 – SUV

  • NIO’s second car ES6 – SUV

  • WM Motor’s first car EX5 – SUV

  • WM Motor’s second car EX6 – SUV

  • Li Auto’s first car ONE – SUV

  • Aiways’ first car U5 – SUV

  • Horizon Robotics’ first car ME7 – SUVTherefore, standing at the year-end of 2017, the development of an SUV model would obviously be much easier, which is also the choice of over 80% of the new car makers.

However, XPeng Motors chairman and CEO He XPeng decided, “Since pure electric SUVs in the future will become a fiercely competitive red sea, we might as well enter a blue ocean market.”

The “pure electric sports sedan” that no one is doing is a blue ocean, and He XPeng hopes to create a “pure electric sports sedan” aimed at the high-end market.

If you understand He XPeng’s strategic plan for XPeng Motors, you will understand this seemingly unwise choice in 2017.

In an interview with Automotive Business Review, He XPeng said:

“In the later stages of China’s automobile industry, if the brand does not move up, there will be no profit, and no profit means no research and development, and no research and development means no differentiation, which is a positive cycle. Therefore, the more you emphasize cost-effectiveness (the brand), the less differentiation you will have. If you do not have differentiation, how can you truly become stronger?”

XPeng Motors’ goal is very clear. If the Chinese automotive industry wants to achieve overtaking in a curve through electrification and intelligentization, car companies must achieve upward breakthroughs. “Only when the brand premium is higher can there be more profit, and car companies will have sufficient funds to do more research and development. With sufficient investment in research and development, companies can produce more valuable products, which will lead to a virtuous cycle for the company.”

Therefore, the XPeng P7 is a very important model for the XPeng brand to achieve upward breakthroughs.

In XPeng Motors’ view, the P7 is a mid-to-high-end sedan that is aimed at people who value endurance, and since electric vehicles are still in the penetration stage in the Chinese market, endurance is still a very important indicator.

In the initial stage of the project, the endurance target set by XPeng internally was 550 km, but battery technology and power consumption control have developed very quickly in the past two years, and XPeng has raised the target endurance of the P7 more than once internally.

XPeng Motors Vice President Liu Minghui told us:

“Last year, XPeng hoped that the endurance of the P7 would reach 650 km internally, but after continuous efforts and optimization, it finally reached 706 km. The development process for electric cars is different from that of traditional cars. For traditional car development, acceleration time, top speed, tank size, and endurance are all predetermined from the beginning. However, for electric cars, especially the issue of endurance, there is a development process because of the rapid development of battery technology and related low-power consumption technology. However, we have always regarded long endurance as an important indicator from the very beginning, and strive to make it the best.”

This is one of the core “differences” that XPeng Motors hopes to achieve, and it is also an important support for brand growth.Since the goal is clear, the remaining is to achieve these goals through technical means. XPeng Motors has two methods to achieve long battery life – “larger battery” and “lower power consumption”.

XPeng has set a new option for itself regarding battery selection

Looking only at the wheelbase data of P7 at 2996 mm, it is not difficult to fit an 80.87 kWh battery, but everyone has overlooked an important point, this is a “sedan“.

Let’s answer a question first, why are there no pure electric sedans on the market except for Tesla?

Don’t argue, I am referring to pure electric sedans developed based on pure electric platforms.

To begin with, they are restricted by the height of the battery.

Compared with SUVs, the height of sedan is significantly reduced, and the height of the battery pack is extremely limited. You can observe that currently most pure electric sedans modified based on gasoline platforms do not affect the interior space of the vehicle, but when you lie down, you can see an obvious battery suspended under the chassis.

The Tesla Model 3 and Model S, which are positioned as sedans, have a height of 1443 mm and 1445 mm respectively. In order to ensure that the overall posture of the P7 is in a flowing coupe shape, XPeng has fixed the height of the car at 1448 mm. However, while achieving a relatively low vehicle height, the ride comfort and passenger space cannot be sacrificed, nor can the ground clearance be reduced. Therefore, the space reserved for the battery is very limited.

In this “vehicle height”, “interior space”, “ground clearance”, and “battery height” game, the first three are differences that consumers can directly perceive. To avoid sacrificing user experience, the only thing that can be sacrificed is the height of the battery.

Tesla uses cylindrical battery cells with a height of only 65-70 mm. After being assembled into packs, the height is less than 120 mm, so it has a natural advantage in height. However, the main domestic batteries are square cells with a height of over 100 mm. After being assembled into packs, the height ranges from 140 mm-200 mm, which is only suitable for SUV models and cannot meet the height requirements of XPeng P7.

Therefore, for an automaker like XPeng who does not manufacture battery cells, there are only two options: the first is to switch to lower cylindrical battery cells, and the second is to collaborate with battery cell suppliers to develop a new type of high-density battery cell with lower height.

After weighing factors such as technological competitiveness, supplier resources, and development costs, XPeng chose to work with CATL to develop a new type of high-density battery cell with lower height.For XPeng, this is obviously a difficult decision.

Because XPeng faces not only high development costs, but also bets on future profit margins.

As a popular battery manufacturer, CATL (Contemporary Amperex Technology Co Ltd) has a constant flow of potential clients knocking on their door. Therefore, there is no reason for CATL to pay for XPeng to develop such a low-height battery and this cost can only be borne by XPeng.

Although the cost is high, XPeng did not back down in order to achieve differentiation. Liu Minghui, Vice President of XPeng Motors, told us that the height of the battery pack of XPeng P7 has been reduced to about 110mm and it is currently the lowest height for a battery pack in China. Combined with the 590 large module solution from CATL, the pack energy density can still reach 170 Wh/kg. This battery is also the first launch for XPeng P7.

For XPeng Motors, the earlier they adopt new technology means the earlier they can occupy users’ minds, just like the “811 competition” in the automotive industry in 2019 and the “Snapdragon 865 chip competition” in the mobile phone industry. Whoever uses it first will be the leader.

But the bigger challenge that follows is, how to reduce the manufacturing cost of the battery cells after mass production?

Liu Minghui, Vice President of XPeng Motors, also admitted that only XPeng’s usage of this battery cell may not be enough to maintain its cost competitiveness.

Therefore, XPeng’s decision involves whether there would be other brands that will use this battery, and the future demand for this battery. Only when the demand for “low height battery cells” in the future increases, with continuous improvement in production scale, can the cost of battery cell manufacturing be reduced, and XPeng P7 can achieve sufficient profit margins.

The decision for strategic direction in automotive engineering has low fault tolerance. Once the direction is defined, heavy investment will be placed on it. XPeng has bet on its future profit margins. Liu Minghui expressed full confidence, as multiple other vehicle manufacturers have already shown considerable interest in this battery cell and pack product platform.

In the battery cell dilemma, XPeng has drawn a new option for themselves – squeezing 80.87 kWh of battery into a 2996mm wheelbase, and a height of 110mm.

From a spatial perspective, it is not easy for XPeng P7 to fit an 80.87 kWh battery, but from the perspective of cruising range, the 706 km NEDC range achieved by the 80.87 kWh battery is not convincing enough. This involves the second method, reducing energy consumption.

The secret to the power consumption control of XPeng P7

Before talking about energy consumption, I would like to clarify a concept: NEDC cruising range is not equal to actual cruising range. This is only a data that the Ministry of Industry and Information Technology tests under predefined conditions, and the actual cruising range depends on the user’s current driving environment.

Although NEDC cruising range is not equal to actual cruising range, the results obtained under unified standards can still be used as a horizontal comparison.XPeng Motors has revealed to us that in the internal test in February this year, with the air conditioning turned on at around 20 degrees Celsius, the actual cruising range is about 600 km, including both high-speed and city driving conditions.

The low power consumption is due to multiple factors.

First of all, the model itself is advantageous as the P7 is a mid-size sedan with a weight lower than 2 tons and a drag coefficient of 0.236 Cd, compared to SUVs.

Secondly, the electric drive efficiency has been improved by adopting the integrated design of front and rear electric drivetrains, which eliminates the high-voltage lines between the motor and control unit to effectively reduce line losses. The electromagnetic and cooling design of the motor is optimized by combining the vehicle working conditions, and the distribution of copper and iron losses is reasonably optimized by matching the IGBT module of the electric control unit, resulting in a larger high-efficiency operation region for the motor. In addition, the P7 is the first in China to adopt an external cooling water channel design for the gearbox, which can reduce the amount of lubricating oil and minimize agitation losses.

There is also a very important point, which is the key to the strong performance of XPeng P7, that is the IGBT.

The maximum output power of the performance version of the XPeng P7 reaches 316 kW, exceeding most electric vehicles on the market. To achieve this high power output, XPeng adopts the Infineon 950A IGBT. XPeng Motors told us that the P7 is the world’s first model to adopt the Infineon 950A IGBT.

You may wonder how NIO ES8 and Tesla Model 3, which were launched before P7, achieve their maximum output power of over 300 kW.

NIO ES8 uses two 820A IGBTs in parallel to achieve a high power output of 480 kW based on the technology constraints at that time, which was the solution for NIO at that time. However, with the development of technology, Infineon has introduced an IGBT power device that can carry a current of up to 950A. Compared with using two 820A IGBTs in parallel, using a single 950A IGBT not only achieves a more compact structure but also reduces the cost.

As for why XPeng Motors did not choose SiC as the power semiconductor in P7, which is more efficient than Model 3, XPeng Motors believes that, from the current industrial and supply chain situation, the efficiency improvement of SiC is limited and the cost of SiC has increased significantly. Therefore, it has low cost-effectiveness for mass production in 2020.

Finally, let’s talk about the question that everyone is most curious about. The battery capacity of XPeng P7’s 656 km and 706 km range models is the same, so where did the extra 50 km come from?

XPeng Motors gave three reasons.

Firstly, the 706 km range version is equipped with low rolling resistance tires and low wind resistance wheels, which lower the driving resistance and improve the range to some extent.

Secondly, the 706 km range version is a basic model without XPilot ADAS (Advanced Driving Assistance Systems) and high-power Danaher audio. These reductions in electronics save some electricity, and the basic model is slightly lighter in weight.

Thirdly, the 706 km range model has more optimization in control strategies. For example, P7’s electronic control strategy will turn off the motor controller when the car is parked to reduce power consumption. Also, P7’s regenerative braking function can last until close to a full stop, and its driving performance is good.

In conclusion

From the vehicle positioning to exterior design, from range to electro-mechanical technology, from ADAS to intelligence, it can be seen that P7 is a vehicle that XPeng Motors has spent a lot of effort developing. However, during the two years of P7’s in-house research and development, Tesla brought its factory to China.

Liu Minghui, Vice President of XPeng Motors, frankly told us:

“Regardless of whether it was 2017 or today, we believe that the best electric drive system at home and abroad is the Tesla Model 3. We believe that Model 3’s electric drive system is competitive in terms of its cost-performance balance, that is, its overall competitiveness. We have benchmarked many indicators against it.”

XPeng Motors has chosen a strong opponent for itself, and of course it has also achieved outstanding results.According to the latest list of exemption from purchase tax released by MIIT, the domestically-produced long-range version of the Model 3 is ready to go, meaning it will be launched in April and inevitably enter the same market as the domestically-produced Model 3, which will be delivered in June, both competing for the same customers.

Despite the two models having similar positioning, there are differences in exterior design, detailed configuration, and final selling price. There is no single dominant player in this segmented market, and it remains to be seen how consumers will choose. We look forward to the answer the market will provide.

This article is a translation by ChatGPT of a Chinese report from 42HOW. If you have any questions about it, please email bd@42how.com.