Calculate home EV charging cost.
Home charging is billed on energy drawn through the meter, which is always more than the energy that reaches the battery. Onboard rectification, thermal management and cable resistance typically lose 8 to 15 percent on AC charging, so the stored kilowatt-hours are divided by the efficiency to get the metered figure before the tariff is applied. Working from state of charge rather than a full-tank assumption matters because most home charging is a partial top-up.
Energy stored
kWh to battery = usable capacity x (target SoC - current SoC) / 100
Metered energy and cost
kWh from meter = kWh to battery / (1 - loss); cost = kWh from meter x tariff
Lithium-ion cells age faster held at high state of charge, and charging slows markedly above 80 percent. Daily charging to 80 with occasional full charges before long trips is the usual manufacturer recommendation.
Yes, often the largest single lever. Dedicated EV tariffs can price overnight energy at a third of the day rate, which for a typical 60 kWh pack is a saving of several currency units per full charge.