Charging & Power
EV Charging Cost Calculator
Calculate precise charging costs including AC/DC efficiency losses and grid power draw.
Primary Metric: Estimated Charging Cost
Charging & Power Deterministic Model v1.2
EV Charging Time Calculator
Estimate replenishment duration across Level 1, Level 2, and DC Fast Chargers.
Charging Session Parameters
Estimate replenishment duration based on power supply Estimated Charging Duration 4h 30m 4.50 decimal hours
Energy Needed: 30.00 kWh
Effective Charging Power: 6.66 kW
Replenishment Band: 20% → 80% (+60%)
DC fast charging follows a non-linear curve. As the pack surpasses 80% SOC, BMS thermal management throttles power to preserve cell health.
Mathematical Formula & Physical Model
Calculates the net energy required to reach target SOC and divides by the effective delivery power of the charging unit.
1
Energy Needed (kWh) = Battery Capacity (kWh) × ((Target SOC% - Current SOC%) / 100) 2
Effective Power (kW) = Charger Power Rating (kW) × (Charging Efficiency% / 100) 3
Charging Time (hours) = Energy Needed (kWh) / Effective Power (kW) Worked Example
Reference Benchmark7.4 kW Home AC Wallbox Session
Adding 30 kWh (from 20% to 80% SOC on a 50 kWh pack) using a 7.4 kW Level 2 single-phase AC wallbox at 90% onboard efficiency.
Battery Capacity 50 kWh
Current SOC 20%
Target SOC 80%
Charger Power 7.4 kW
Efficiency 90%
Frequently Asked Questions
Why does DC fast charging slow down after 80% SOC?
Lithium-ion battery cells utilize a constant-current constant-voltage (CCCV) charging profile. As cells reach saturation around 80% SOC, current is tapered to prevent lithium plating, overheating, and premature degradation.
What is the bottleneck: the charger or the vehicle onboard charger (OBC)?
On AC charging, the vehicle onboard charger limits acceptance power. If a 22 kW AC point is plugged into a car with a 7.2 kW OBC, the vehicle charges at only 7.2 kW.