ev-charging-time-calculator

All lithium-ion batteries — including those in electric vehicles — use a two-stage charging process. In stage 1 (constant current / CC phase), the charger delivers maximum power up to approximately 80% SoC, filling the battery quickly. In stage 2 (constant voltage / CV phase), the charger reduces current to protect the battery cells from overcharging, which degrades lithium-ion chemistry rapidly. This taper is not a bug or a charger limitation — it is a deliberate battery protection measure. The practical consequence: charging from 0–80% takes roughly the same time as charging from 80–100%, even though it is only half the energy. For road trips, most EV planning apps recommend charging to 80% at fast chargers and continuing — it is much more time-efficient than waiting for 100%.

Home charging (2026 average German household tariff ~€0.29–0.34/kWh): charging a 60 kWh battery from 20% to 80% costs approximately €10.50–12.20 (48 kWh × price), giving roughly 250–300 km of range — equivalent to about €3.50–4.50/100km. Public AC charging (~€0.35–0.55/kWh): same 48 kWh charge costs €16.80–26.40. DC rapid charging at highway stops (€0.49–0.89/kWh depending on network): €23.50–42.70 for the same session. The cost difference between home and public DC rapid is roughly 3–4×, which is why EV owners who can charge at home do 80–90% of their charging there. With home solar PV, the effective charging cost can drop to near €0 during peak generation hours.

Yes — cold batteries charge significantly more slowly than warm ones. Below approximately 10°C, DC fast charging speed can be reduced by 30–70% until the battery management system (BMS) has warmed the battery to its optimal operating range (typically 25–35°C). Most modern EVs include battery pre-conditioning: when you set a DC charging station as your navigation destination, the car begins warming the battery 15–20 minutes before arrival, ensuring you arrive with the battery ready for full charging speed. Without pre-conditioning (or in vehicles without this feature), arriving at a DC charger in winter can mean starting at 20–30 kW instead of the rated 150+ kW, with speed gradually increasing as the battery warms. The charging time calculator includes a winter mode that applies a conservative thermal management correction factor.

For most households, an 11 kW three-phase wallbox is the optimal choice. It charges a 60–80 kWh battery overnight in 5–8 hours — more than fast enough for typical daily mileage of 40–80 km. A 22 kW wallbox charges twice as fast but most EVs only accept 11 kW AC anyway (check your vehicle's AC charge rate limit), so the extra power is wasted. A 3.7 kW single-phase wallbox is sufficient only for low daily mileage or plug-in hybrids with small batteries. Installation cost for a standard 11 kW wallbox in Germany (2026): typically €800–1,500 including KEBA/Mennekes/Heidelberg hardware, electrical work, and connection to your home circuit. If you have a PV system, choose a wallbox with solar charging integration to maximise cheap self-generated electricity for vehicle charging.