{"success":true,"version":"v1","request":{"tool":"get_calculator_schema","calculator_id":"ev-charging-time"},"result":{"entity_type":"calculator","id":"ev-charging-time","calculator_id":"ev-charging-time","canonical_url":"https://tttkmbb.com/energy/ev-charging-time","name":"EV Charging Time Calculator","title":"EV Charging Time Calculator – Hours to Charge from Battery Size, State of Charge, Charger Power and Efficiency","category":"energy","category_name":"Home Energy & Electrical","tool_name":"estimate_ev_charging_time","featured_mcp_tool":true,"description":"Estimates how long an electric vehicle takes to charge between two states of charge from its battery capacity, the charger power (capped by the onboard charger for AC charging) and the charging efficiency, plus the energy drawn from the grid and its cost.","use_when":"You want to know how long an EV needs on a home wallbox, a public AC post or a DC fast charger to reach a target charge, or what the session costs at a given electricity price.","do_not_use_when":"You need a battery's charge time from ampere-hours and charger current (use battery-charge-time) or the driving range the added energy gives (use ev-range-efficiency); DC fast charging above about 80 % tapers strongly and takes longer than this constant-power estimate.","inputs":[{"name":"battery_capacity_kwh","label":"Battery capacity","type":"number","unit":"kWh","required":true,"max":1000,"exclusive_min":0,"description":"Usable battery capacity in kilowatt-hours (e.g. 40, 60, 75, 100).","example":75},{"name":"start_percent","label":"Start charge","type":"number","unit":"%","required":false,"default":20,"min":0,"max":100,"description":"State of charge at the start of the session.","example":20},{"name":"target_percent","label":"Target charge","type":"number","unit":"%","required":false,"default":80,"min":0,"max":100,"description":"State of charge to reach; must be higher than start_percent.","example":80},{"name":"charger_power_kw","label":"Charger power","type":"number","unit":"kW","required":true,"max":1000,"exclusive_min":0,"description":"Power the charging point delivers: 1.4–2.3 kW household socket (Level 1), 7–22 kW wallbox / AC post (Level 2), 50–350 kW DC fast charger.","example":7},{"name":"max_onboard_charger_kw","label":"Onboard charger limit","type":"number","unit":"kW","required":false,"max":1000,"exclusive_min":0,"description":"Optional maximum AC charging power of the car's onboard charger (commonly 7.4 or 11 kW); the effective power is the lower of the two. Omit for DC charging.","example":11},{"name":"charging_efficiency_percent","label":"Charging efficiency","type":"number","unit":"%","required":false,"default":90,"min":50,"max":100,"description":"Share of grid energy stored in the battery; 85–92 % is typical for AC charging (onboard charger and battery losses).","example":90},{"name":"electricity_price_per_kwh","label":"Electricity price","type":"number","unit":"per kWh","required":false,"min":0,"max":100,"description":"Optional price per kWh in your currency for the cost of the session (grid energy × price).","example":0.3}],"outputs":[{"name":"energy_added_kwh","label":"Energy added to battery","type":"number","unit":"kWh","decimals":2,"description":"battery_capacity_kwh × (target_percent − start_percent) / 100."},{"name":"energy_from_grid_kwh","label":"Energy from grid","type":"number","unit":"kWh","decimals":2,"description":"energy_added_kwh / efficiency (what the meter records)."},{"name":"effective_power_kw","label":"Effective charging power","type":"number","unit":"kW","decimals":2,"description":"min(charger_power_kw, max_onboard_charger_kw)."},{"name":"charging_time_hours","label":"Charging time","type":"number","unit":"h","decimals":2,"description":"energy_from_grid_kwh / effective_power_kw."},{"name":"charging_time_text","label":"Charging time (text)","type":"string","decimals":4,"description":"Charging time as hours and minutes, e.g. \"7 h 9 min\"."},{"name":"cost","label":"Session cost","type":"number","decimals":2,"description":"energy_from_grid_kwh × electricity_price_per_kwh; only when a price is given."},{"name":"range_note","label":"Range note","type":"string","decimals":4,"description":"Approximate driving range the added energy gives at an example consumption of 160 Wh/km."}],"input_schema":{"type":"object","properties":{"battery_capacity_kwh":{"description":"Usable battery capacity in kilowatt-hours (e.g. 40, 60, 75, 100). Unit: kWh.","type":"number","maximum":1000,"exclusiveMinimum":0,"examples":[75],"x-unit":"kWh"},"start_percent":{"description":"State of charge at the start of the session. Unit: %.","type":"number","minimum":0,"maximum":100,"default":20,"examples":[20],"x-unit":"%"},"target_percent":{"description":"State of charge to reach; must be higher than start_percent. Unit: %.","type":"number","minimum":0,"maximum":100,"default":80,"examples":[80],"x-unit":"%"},"charger_power_kw":{"description":"Power the charging point delivers: 1.4–2.3 kW household socket (Level 1), 7–22 kW wallbox / AC post (Level 2), 50–350 kW DC fast charger. Unit: kW.","type":"number","maximum":1000,"exclusiveMinimum":0,"examples":[7],"x-unit":"kW"},"max_onboard_charger_kw":{"description":"Optional maximum AC charging power of the car's onboard charger (commonly 7.4 or 11 kW); the effective power is the lower of the two. Omit for DC charging. Unit: kW.","type":"number","maximum":1000,"exclusiveMinimum":0,"examples":[11],"x-unit":"kW"},"charging_efficiency_percent":{"description":"Share of grid energy stored in the battery; 85–92 % is typical for AC charging (onboard charger and battery losses). Unit: %.","type":"number","minimum":50,"maximum":100,"default":90,"examples":[90],"x-unit":"%"},"electricity_price_per_kwh":{"description":"Optional price per kWh in your currency for the cost of the session (grid energy × price). Unit: per kWh.","type":"number","minimum":0,"maximum":100,"examples":[0.3],"x-unit":"per kWh"}},"additionalProperties":false,"required":["battery_capacity_kwh","charger_power_kw"]},"output_schema":{"type":"object","properties":{"energy_added_kwh":{"description":"battery_capacity_kwh × (target_percent − start_percent) / 100. Unit: kWh.","type":"number","x-unit":"kWh"},"energy_from_grid_kwh":{"description":"energy_added_kwh / efficiency (what the meter records). Unit: kWh.","type":"number","x-unit":"kWh"},"effective_power_kw":{"description":"min(charger_power_kw, max_onboard_charger_kw). Unit: kW.","type":"number","x-unit":"kW"},"charging_time_hours":{"description":"energy_from_grid_kwh / effective_power_kw. Unit: h.","type":"number","x-unit":"h"},"charging_time_text":{"description":"Charging time as hours and minutes, e.g. \"7 h 9 min\".","type":"string"},"cost":{"description":"energy_from_grid_kwh × electricity_price_per_kwh; only when a price is given.","type":"number"},"range_note":{"description":"Approximate driving range the added energy gives at an example consumption of 160 Wh/km.","type":"string"}}},"formula":"energy_added_kwh = battery_capacity_kwh × (target_percent − start_percent) / 100; energy_from_grid_kwh = energy_added_kwh / (charging_efficiency_percent / 100); effective_power_kw = min(charger_power_kw, max_onboard_charger_kw); charging_time_hours = energy_from_grid_kwh / effective_power_kw; cost = energy_from_grid_kwh × electricity_price_per_kwh","method":"Constant-power model. AC charging is limited by the car's onboard charger (U.S. DOE: Level 1 ≈ 1.4 kW, Level 2 up to 19.2 kW); DC fast charging is limited by the car's charge curve and slows sharply above about 80 %, so real DC sessions to 100 % take considerably longer.","sources":[{"name":"U.S. DOE Alternative Fuels Data Center – Charging Electric Vehicles at Home","url":"https://afdc.energy.gov/fuels/electricity-charging-home","type":"government","retrieved_at":"2026-09-24"},{"name":"Wikipedia – Charging station","url":"https://en.wikipedia.org/wiki/Charging_station","type":"reference","retrieved_at":"2026-09-24"}],"freshness":{"type":"static","max_age_seconds":null,"note":"Deterministic formula with fixed constants; results never go stale. Inputs supplied by the caller determine the output."},"examples":[{"name":"75 kWh, 20 → 80 %, 7 kW wallbox, 90 %, 0.30 per kWh","inputs":{"battery_capacity_kwh":75,"start_percent":20,"target_percent":80,"charger_power_kw":7,"charging_efficiency_percent":90,"electricity_price_per_kwh":0.3},"expected":{"energy_added_kwh":45,"energy_from_grid_kwh":50,"effective_power_kw":7,"charging_time_hours":7.14,"charging_time_text":"7 h 9 min","cost":15},"url":"https://tttkmbb.com/api/v1/calculate/ev-charging-time?battery_capacity_kwh=75&start_percent=20&target_percent=80&charger_power_kw=7&charging_efficiency_percent=90&electricity_price_per_kwh=0.3"},{"name":"60 kWh, 10 → 100 %, 11 kW post, 7.4 kW onboard charger","inputs":{"battery_capacity_kwh":60,"start_percent":10,"target_percent":100,"charger_power_kw":11,"max_onboard_charger_kw":7.4},"expected":{"energy_added_kwh":54,"energy_from_grid_kwh":60,"effective_power_kw":7.4,"charging_time_hours":8.11,"charging_time_text":"8 h 6 min"},"url":"https://tttkmbb.com/api/v1/calculate/ev-charging-time?battery_capacity_kwh=60&start_percent=10&target_percent=100&charger_power_kw=11&max_onboard_charger_kw=7.4"}],"faq":[{"q":"Why is my car charging slower than the wallbox rating?","a":"The onboard charger caps AC power (many cars accept 7.4 kW single-phase or 11 kW three-phase), and cold or nearly full batteries reduce the rate further. Enter the onboard limit in max_onboard_charger_kw."},{"q":"Does the efficiency change the cost?","a":"Yes. The meter records grid energy, which is the battery energy divided by the efficiency, so a 90 % efficient session costs about 11 % more than the energy stored."},{"q":"How long does DC fast charging take?","a":"The estimate holds for 10–80 %; above 80 % chargers taper to protect the battery, and the last 20 % can take as long as the first 70 %."}],"tags":["ev charging time","how long to charge electric car","wallbox charging time","kwh charging calculator","ev charging cost","level 2 charging"],"related":[{"calculator_id":"ev-range-efficiency","reason":"Range the added energy gives at the car's consumption."},{"calculator_id":"battery-charge-time","reason":"Charge time from ampere-hours and charger current."},{"calculator_id":"electricity-cost","reason":"Cost of the same kWh at several tariffs."}],"links":{"html":"https://tttkmbb.com/energy/ev-charging-time","markdown":"https://tttkmbb.com/energy/ev-charging-time.md","json":"https://tttkmbb.com/energy/ev-charging-time.json","api":"https://tttkmbb.com/api/v1/calculate/ev-charging-time","schema":"https://tttkmbb.com/api/v1/calculators/ev-charging-time","openapi":"https://tttkmbb.com/openapi.json","mcp":"https://tttkmbb.com/mcp"},"version":"v1","updated_at":"2026-09-24"},"timestamp":"2026-09-24T03:45:07Z"}