BYD e-Platform 3.0

The 2021 BYD e-Platform 3.0 brought quite a few changes to the battery pack design. Now with more data available it is worth a more detailed look. BYD make a number of claims around the battery in this design:

  • integrated 8-in-1 assembly => Cell to Body design
  • structural architecture
  • high expandability of the e-platform 3.0 creates a larger axle-to-length ratio => A-class cars to D-class cars
  • overall battery pack height = 110mm => lower height for overall body and battery package (10mm overall gain)
  • lower body posture => ultra-low wind resistance

The platform is likely to be updated to 4.0 in 2024.

Cell Orientation

With the update of the battery pack design and integration the cell orientation has changed. Originally the cells ran across the pack from the left to right side (east-west). e-Platform 3.0 has changed this so the cells now run front to back (north-south).

BYD blade battery pack
BYD Blade Battery
BYD Seal Battery
BYD e-Platform 3.0 Battery

Why make this change?

  • longer cells => improved density => higher pack density
    • BYD claim 10% improvement in energy density [1], this might be volumetric as the gravimetric gain is only 2.5%
      • BYD Blade Pack (Han) = 144Wh/kg
      • BYD e-Platform 3.0 (Seal) = 148Wh/kg
  • cell terminals more protected => improved side impact safety
  • shorter overall cell stack => easier to support cell compressive forces
  • vent paths easier to manage at front and rear of the pack => improved safety
BYD nail penetration test of their blade cell

BYD Blade Nail Penetration Test

BYD mention the nail penetration test in their literature and hence it was worth looking at this in-depth.

Cell to Body

BYD [1] list the benefits of this approach as:

  • efficiency
  • aerodynamics
  • power
  • body rigidity
  • space utilisation

This post has been built based on the support and sponsorship from: MAHLE Powertrain LtdThermo Fisher ScientificEatron TechnologiesAbout:Energy and Quarto Technical Services.

BYD cell to body battery technology

The latest image for the BYD Seal U appears to show a very similar structural approach. Note: the image below of the Seal U has the lid of the battery pack removed. In the design the lid of the pack forms the floor of the body structure.

BYD Seal U
BYD Seal U [2]
BYD platfor 3 crash structure
Force paths through front longitudinals and subframe and then into sills and battery pack [3]

BYD show the battery being part of the overall crash structure. The front subframe appears to be aligned with the base of the battery pack. The flat rectangular battery pack is described as a “honeycomb structure”. The fact the battery pack is flat, 110mm in thickness and the cells are bonded into the structure means that this is an extremely stiff structural element. This is reflected in a body torsional stiffness of 40,500 Nm/degree.

BYD platfor 3 crash structure

Charging

e-Platform 3.0 uses the motor inductor to replace the boost inductor in the original boost solution, to meet the 420-750V voltage range of charging piles with high-power DC charging.

References

  1. BYD SEAL Dynamic and Intelligent, BYD
  2. BYD Seal U, BYD EU
  3. Why is BYD’s e-Platform 3.0 so special?, BYD
  4. BYD Seal Review, AutoCar

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