A brief analysis of Ford Mustang Mach-E's localized battery system

Some time ago, I saw Ford demonstrate the battery system of the domestic version of Mustang Mach-E at the Tianma Racing Circuit. Overall, it has done a very good job of localization. Today I will mainly sort it out and discuss it.

Figure 1 Differences in battery systems between the domestic and foreign versions of Mustang Mach-E

Battery selection

The battery system of Mustang Mach-E uses LG batteries abroad, but basically adopts a module design in China, and the battery cell uses BYD's ternary lithium 58.5Ah small-capacity battery cell design. BYD has begun to separate its battery business. When BYD's ternary lithium was first supplied, its main customers were Changan and Ford, while its blade battery has developed FAW as a customer. As shown in the figure below, we can see that BYD's current customer status of batteries is still mainly around meeting their own needs.

Note: BYD's battery supply is also increasing in foreign brands, while the demand for domestic brands is relatively low in the short term.

Figure 2 BYD's installed capacity of battery cells

Regarding this module, in order to ensure safety, BYD uses a high-strength diaphragm with a ceramic layer and an explosion-proof valve design inside the battery cell to avoid direct contact and short circuit between the positive and negative electrodes as much as possible. The battery module reserves expansion space between the battery cells and is equipped with aerogel to minimize or even prevent the chain reaction generated during the thermal diffusion of the battery. Through a series of designs, in the thermal runaway test, the thermal runaway propagation time of the battery system is about tens of minutes, and a thermal runaway warning is issued to the user within 2 seconds.

Figure 3 Battery module provided by BYD

There are 22 modules in total, and the water cooling system is basically based on the original Mach-E. So after comparison, the main differences between the soft-pack and square-shell designs are:

Figure 4 Schematic diagram of the entire battery system of Mustang Mach-E

1) The module was fully designed. The module soft package was designed to be 10. In this early domestic plan, 22 were used. Two were put together and covered with mica sheets, so it looks like a double-piece module, but the structure inside is complete. It should be noted that due to the design of the battery box, there are also two types of modules, long and short, of which two are particularly small;

2) Since the modules are separated, the busbars have been re-optimized. From the overall layout point of view, the routing path is much better.

The design of the entire battery management system, distribution box and central wiring is basically exactly the same.

Figure 5 Design of the domestic version

Ford's next step: This generation of Mustang Mach-E is more like a start. From my understanding, since Ford has a large cooperation project with SK in the United States and has adopted Volkswagen's MEB platform in Europe, it is likely that Ford will continue to cooperate with BYD in its future "small plate" in China.

Design of BDU

Next, let me talk about my previous job - BDU design. I personally don't like the long snake formation of the Mustang Mach-E, as the overall layout efficiency is relatively low.

From the contactor point of view, four TE large high-voltage contactors and a small contactor are used, and a fuse is embedded. Overall, Ford still left some space in the length direction, so that the main fuse and contactor can be placed better. From the overall insulation point of view, this insulation design with a plastic seat combined with a busbar quick-plug design is a more convenient assembly solution. If the design is considered for 800V, such an inverted design combined with an embedded busbar can indeed be more effectively insulated.

Figure 6 Ford's TE design

The centralized acquisition of Mustang Mach-E is almost the same as that of iX3, so the cost of the acquisition cables and connectors is not low. I have previously obtained an analysis of the iX3 acquisition board, and will make a comparison of this part later.

Figure 7 Ford Mach-E’s centralized data acquisition cable

summary:

As Tesla has fully introduced iron-lithium batteries, LG's installed capacity has plummeted. I believe that all foreign brands will still give priority to domestic battery companies' cells in China. In the second half of 2022, BYD's installed capacity will be further diversified, and we will also see more blade batteries installed in other companies' cars.