Vinfast Theon S Battery

Vinfast Theon S

The Vinfast Theon S battery for the electric 2 wheeler from Vietnam. The original version had swappable battery packs that used Samsung 21700 NCA cells.

In 2022 VinFast changed the design to a fixed Lithium Iron Phosphate (LFP) pack that uses LFP prismatic cells from Gotion [3].

Metrics

  • Gravimetric Energy Density
    • Pack = 131 Wh/kg
    • Cell = 172.3 Wh/kg
  • Gravimetric Power Density
    • Peak = 404 W10s/kg
    • Contintuous = 243 Wcont/kg
    • Charge = 68 Wcont/kg
  • Usable Energy = 3.48 kWh (Total = 3.66 kWh)
    • SoC Window = 95%
  • Nominal Voltage = 70.4V
    • Voltage Range = 75.9V to 61.6V
  • Nominal Capacity = 52 Ah
  • Configuration = 22 s 1 p
  • Pack DCIR ~ 0.055 Ω10s
  • Power
    • Peak = 11.3 kW10s
    • Continuous = 6.8 kWcont
  • Fast Charging Power = 1.9 kW
Vinfast Theon S battery
Battery pack with the top half of the case removed [2]

This post has been built based on the support and sponsorship from: Thermo Fisher ScientificEatron TechnologiesAbout:EnergyAVANT Future MobilityQuarto Technical Services and TAE Power Solutions.

Vinfast Theon S battery frame
  • Pack Mass = 28 kg
    • Cell Mass = 21.3 kg
    • Pack-Cells = 6.7 kg
    • Cell to Pack Ratio = 75.9 %

The pack uses an aluminium cast base. This has the fixing points located around the perimeter to allow the pack to be bolted into the scooter frame.

A one piece injection moulded lid fits over and bolts down to the aluminium base with a seal fitted into the lid [2].

Vinfast Theon S battery seal

The top half of the enclosure has the seal set into a moulded in rectangular groove.

Vinfast Theon S battery vent

Note the underside of the vent disc in the top surface of the upper pack enclosure. There appear to be two vent discs in total.

Vinfast Theon S battery

The second tier of the pack has cells and control system all attached via the inner plastic support/shielding.

Vinfast Theon S battery

Harness and busbar cables run up the side of the second teir and are fixed to the inner housing. The second tier has a more substantial plastic base with the upper cover clipping to the lower section.

Vinfast Theon S battery contactor

The main contactor is a Hongfa HFE80V-200/150-12-HTC5Y [4]. The high level specifications are:

  • 200A continuously at 85°C
    • 800A for 10s
  • Contact resistance ≤1.0mΩ (at 20A)
  • Max switching voltage = 250VDC
  • Max breaking current = 400A

Cells

  • Cell Make = Gotion
  • Chemistry = Lithium Iron Phosphate
  • Format = Prismatic
  • Nominal Capacity = 52 Ah
  • Nominal Voltage = 3.2 V
  • Nominal energy = 166.4 Energy Wh
  • Mass = 0.966 kg
  • DCIR = 0.0025 Ω [10s 50% 25°C)

References

  1. Vinfast Theon Specifications, Vinfast
  2. “Khám” pin LFP trên các dòng xe mới VinFast S 2022, Vinfast Vento, FixBox, YouTube
  3. Vietnam’s Electric Two-Wheelers, CleanTechnica
  4. HFE80V-200/150-12-HTC5Y, Hongfa

battery pack mass versus total energy for all packs in the database and BMW picked out in red

The battery pack database is now available as an excel file via a download. This includes the data from this battery pack and many more (see page for details).

Benchmark your design against the market and create plots easily.

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