Twice the voltage, half the current
At the same transferred power, raising voltage reduces current. This simple relationship helps explain the appeal of high-voltage EV architecture.
Canvas of Knowledge · 14 November 2026 · Illustrated explainerPOWER: P = V × I
In an idealised 200kW example, 400V requires 500A, while 800V requires 250A. These are calculated teaching values, not vehicle specifications.
CABLE HEATING: I²R
If the same conductor resistance remains unchanged, halving current reduces its resistive heating to one quarter. For an illustrative 0.01Ω resistance, losses fall from 2,500W to 625W.
THE LIMIT OF THE EXAMPLE
This does not make the entire car four times more efficient. Insulation, switching devices, conversion losses, thermal systems and real operating voltage still affect the engineering trade-off.
THE IDEA TO KEEPVoltage can reduce current-related losses, but efficiency belongs to the complete system.
Sources & further reading
Sources reviewed 14 November 2026. Specifications and availability depend on the product, market and date. Source organisations do not endorse this website.