400 V and 800 V architectures
Why doubling voltage halves current, and what it costs.
You'll learn
- Explain 400 v and 800 v architectures at engineering level
- Read the numbers that define the behaviour
- Apply the idea to a real pack
Overview
Power is voltage times current. If you want 350 kW into a pack, you can either push 875 A at 400 V or 437 A at 800 V. One of those needs far heavier cables.
In depth
Calculator
Power Converter
Convert between kW, horsepower and metric PS.
kW
Mechanical horsepower
201hp
Metric PS
204PS
Watts
150000W
Formula
1 kW = 1.34102 hp = 1.35962 PSMechanical horsepower and metric PS are both historical units defined against different reference weights, which is why they differ by about 1.4%.
Example: 150 kW = 201 hp = 204 PS.
- EV power figures are peak, and can only be held while the pack is warm and above ~30% SOC.
- Continuous power is often half the peak figure.
- Torque at the wheel matters more than kW for acceleration off the line.
| Aspect | 400 V | 800 V |
|---|---|---|
| Cable mass for 350 kW | High | About half |
| I²R losses | Higher | Lower |
| Component cost | Mature, cheap | SiC needed, dearer |
| Charger compatibility | Universal | Needs a boost stage on 400 V DC posts |
| Typical peak charge | 150–250 kW | 250–400 kW |
Quiz
Voltage architecture
- 1
For the same power, doubling voltage ____ the current.
Key takeaways
Remember this
- Higher voltage means lower current for the same power.
- 800 V cuts cable mass and conduction losses.
- Silicon carbide power electronics make 800 V practical.
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