How it works
Charging time is the energy needed (capacity × target-minus-current %) divided by the charger's effective power. We assume only 90% of rated charger power is usable, accounting for cable and inverter losses.
FAQ
Q. Does fast charging always match the estimate?
A. No — most batteries taper charging speed sharply above ~80%, so the last stretch often takes longer than a linear estimate.
Q. Why does slow charging take so long?
A. Slow chargers (~7kW) deliver far less power than fast chargers (50-350kW), so a large battery typically needs 6+ hours to fill.