GM's CTC structure and low battery

In the North American market, there are two directions that General Motors must consider, one is how to compete on medium and large SUVs and pickup trucks, and the other is how to do electrification of American muscle sports cars. These are all money-making models of General Motors, and as Tesla and Ford and The Strand (Chrysler brand) enter this field, the so-called investment in electrification, at least in these areas of good design.

Figure 1. In addition to the conventional battery series, the general battery series also has low batteries and high batteries

Part 1 Universal structured battery design

In the design concept of GM and Ford, the structured battery is actually considered from the body structure, and the design core is to do a design in the load-bearing body of the pickup truck and the SUV. In essence, this and Rivian's skateboard chassis is the same thing, I have to emphasize that now the CTC done in the United States in pickups/SUVs and the CTC done by Tesla and Chinese startups including the Ningde era are actually inconsistent.

Remarks: I would like to separate this concept to see how everyone can do what they want to do in a concept.

The following figure is the chassis design of the general design displayed in the design, the whole integration is indeed reflected in the vehicle level, the battery module is loaded into it, the benefits are not Z-oriented, the height of the battery is thick enough, the SUV and pickup of the large tire do not care at all, plus the Hummer EV can also be raised through the active suspension, its biggest benefit is the overall leather solid

Figure 2. Feel the finished products designed by North American engineering

In the normal passenger car design, the use of high-strength "well" glyph frame structure, ultra-high-strength steel accounted for 37.5%, the battery pack in the beam and the upper cover assembly side guard beam using 1500MPa ultra-high-strength steel, pallet assembly using 10000MPa bottom protection.

I've always felt that these are a bit overdesigned for ordinary passenger cars, but in American muscle SUVs and pickups, isn't it standard design? Therefore, the battery high-strength structure extended to the passenger car may be slightly heavier in the passenger car, but in the American pickup design, this thing is the world's first crash-resistant battery design.

Figure 3. GM's structured batteries

In the general consideration, this type of battery structure design is a special consideration, combined with the design of high-strength steel, to create a very solid chassis, from the structural point of view, the battery pack can not be to be solid.

Figure 4. GM's batteries match the body

Therefore, the battery is very strong, and the design of high-strength steel is actually considered from the beginning of the vehicle structure.

Figure 5. Batteries under conductive structures

The following figure is not a double-layer steel beam structure, casting a particularly strong battery shell to meet the needs of the entire body.

Figure 6. GM's double-layer battery

There is also a very interesting place, that is, due to the charging requirements of 800V, as mentioned earlier, the 800V system can achieve 800V fast charging through voltage configuration.

Table 1. The general pickup configuration is 400V

The core problem here is that the current of 400V charging is too large, so the 800V series structure is used to charge.

Figure 7. 800V fast charging design

I think this was caused by not considering it when I was planning it. General company may need to adjust this part in the later stage, the back of the 800V SiC system for 160kwh ~ 200kwh has a good energy-saving effect, so toss is not as good as directly do high-voltage batteries, which is so for 800V charging and do the configuration of high-voltage relays.

Part 2 Low top low battery design

Then there is this low-top battery design, my understanding of this and i4 ideas are similar, all low battery design, must consider how to take into account the energy. At present, the choice of low batteries is either stacked with this soft bag, or cylindrical, or with a blade to do CTC.

Figure 8. Vertical and stacked arrangement of soft pack batteries

The design of the following package, the probability is the final destination of the sports car, anyway, the amount is not large, so there is no problem.

Figure 9. The design orientation of the soft pack battery

Summary: GM is a company that is very good from a strategic point of view, but it is true that at the executive level, it is a bit difficult to simply expect to be in the 50-60 engineering execution layer to do pioneering design, which can only be said to be working on Frost. Writing here is really nostalgic, innovation of this thing still has to be done by young people, the elderly to help, not the old people to take the idea to let young people fill in.