"How long does it take to charge?" is the first question of anyone considering an electric car. The answer depends on three numbers: battery size, charger power and how much of it the car accepts. Here is the formula, a table and a few practical rules.
A simple formula
Charging time in hours = energy to add (kWh) ÷ actual charging power (kW). The energy to add is the difference between the target and the current state of charge. The actual power is always the lower of the charger's output and what the car can accept. The second part is often overlooked: a 22 kW wallbox charges a car with an 11 kW on-board charger exactly as fast as an 11 kW wallbox.
Example: a Škoda Enyaq with a 77 kWh battery and an 11 kW on-board charger arrives at 20 % and you want 80 %. You need 60 % of 77 kWh = 46 kWh. On an 11 kW wallbox that takes 46 ÷ 11 = 4.2 hours. From a 2.3 kW household socket, 20 hours.
Table: charging time by power and battery size
Topping up from 20 to 80 % (60 % of capacity), rounded. Assumes the car accepts the given power.
| Battery | Socket 2.3 kW | Wallbox 1-ph 3.7 kW | Wallbox 1-ph 7.4 kW | Wallbox 11 kW | Wallbox 22 kW | DC 40 kW | DC 100 kW |
|---|---|---|---|---|---|---|---|
| 40 kWh (small car) | 10.5 h | 6.5 h | 3.2 h | 2.2 h | 1.1 h | 40 min | 20 min |
| 60 kWh (compact) | 16 h | 10 h | 5 h | 3.3 h | 1.6 h | 55 min | 25 min |
| 77 kWh (mid-size SUV) | 20 h | 12.5 h | 6.2 h | 4.2 h | 2.1 h | 70 min | 30 min |
| 100 kWh (large SUV) | 26 h | 16 h | 8 h | 5.5 h | 2.7 h | 90 min | 40 min |
What makes charging take longer
- The car's on-board charger. Most often 11 kW; plug-in hybrids and smaller cars have 3.7 or 7.4 kW single-phase. Look for "AC charging" in the data sheet.
- Battery temperature. In frost the car first warms the battery and limits power. On AC the effect is small, on DC it is decisive.
- State of charge. AC charging runs at constant power almost to 100 %; DC charging drops to a fraction of the power above 80 %. That is why fast charging is planned to 80 %.
- Load management. A smart wallbox lowers power during the house's peak consumption or when solar surplus is small. The car charges more slowly but the fuse stays in. Overnight this plays no role.
- Single-phase charger on a three-phase wallbox. A car with a 7.4 kW single-phase charger takes only 3.7 kW from an 11 kW wallbox because the wallbox delivers 16 A per phase. For such cars a 22 kW wallbox (32 A) is better: they take 7.4 kW from it.
AC or DC: what is the difference
| AC charging (wallbox) | DC fast charging | |
|---|---|---|
| Where the current is converted | in the car's on-board charger | in the station, DC goes straight to the battery |
| Typical power | 3.7 to 22 kW | 40 to 400 kW |
| Limit | the car's on-board charger | the battery and its temperature |
| Connector | Type 2 | CCS2 |
| Price per kWh | EUR 0.16 to 0.28 at home | EUR 0.48 to 0.72 public |
| Effect on the battery | gentle | faster degradation with frequent use |
| Where it makes sense | home, work, hotel, anywhere the car parks for hours | motorways, fleets with fast turnover |
For companies whose cars rotate during the day a combination works well: e:car WALL PRO AC wallboxes for staff parking and one e:car DC WALL 40 kW for a quick top-up between trips.
Three sample days
| Situation | Daily consumption | Time on an 11 kW wallbox | Time on a 2.3 kW socket |
|---|---|---|---|
| Commute 40 km a day, compact at 17 kWh/100 km | 7 kWh | 40 minutes | 3 hours |
| Sales rep 180 km a day, SUV at 20 kWh/100 km | 36 kWh | 3.3 hours | 16 hours (not enough overnight) |
| Back from a weekend, 77 kWh battery at 10 %, need 100 % by morning | 69 kWh | 6.5 hours (overnight) | 30 hours (not enough) |
| Winter, commute 60 km, consumption +25 % | 13 kWh | 1.2 hours | 5.7 hours |
The comparison shows where the socket ends: above 100 km a day or after a longer trip it no longer refills the car overnight. An 11 kW wallbox handles all common scenarios with margin, even in winter.
How to read a charging curve
On AC the power is practically constant from the start to about 95 % and then drops to zero within minutes, which is why simple division works. On DC the curve is hill-shaped: peak power between 10 and 50 %, above 80 % it falls to 20 or 30 kW and the last 10 % take longer than the first 50 %. A "charged in 30 minutes" claim for fast chargers therefore always means 10 to 80 %. For road trips: charge briefly and often between 10 and 70 %, then fill up calmly at home overnight.
Sharing power between cars
The dual-outlet e:car WALL double with a total of 22 kW charges two cars at 11 kW each. If the connection allows only 11 kW in total, each car gets 5.5 kW and the time doubles, still enough overnight for 55 kWh per car. In companies and apartment buildings the power is shared between dozens of stations by priority; each car still gets the 20 to 40 kWh it needs during a working day.
How to charge faster at home when you need to
- Check the car's on-board charger. If it has 22 kW, consider a 22 kW wallbox with a 3× 32 A supply.
- For cars with a 7.4 kW single-phase charger choose a 22 kW wallbox (32 A per phase); from an 11 kW station they get only 3.7 kW.
- Switch the SMART wallbox to Boost mode, which ignores photovoltaics and charges at full power.
- Charge right after arriving while the battery is warm.
- Charge to 80 % unless you need the full range; the last percent take disproportionately long even on AC.
Pick the right wallbox for your car
Tell us the model. We advise on power, socket or cable, and prepare a quote with installation. Shipping across the EU.
Summary in five points
- Charging time = energy to add divided by the actual power, set by the weaker link: the car's charger or the station.
- An 11 kW wallbox adds 60 % of a 60 kWh battery in 3.3 hours; a socket needs 16 hours.
- Overnight an 11 kW wallbox delivers over 100 kWh; most drivers never use faster home charging.
- Plan DC fast charging to 80 %; above that the power drops sharply.
- Cars with a 7.4 kW single-phase charger need a 22 kW wallbox (32 A per phase); from 11 kW they get only 3.7 kW.
Často kladené otázky
How long does it take to charge an electric car at home?
On an 11 kW wallbox a 60 kWh battery charges from 20 to 80 % in 3.3 hours, a 77 kWh battery in 4.2 hours. From a 2.3 kW socket it takes 16 to 20 hours. Overnight an 11 kW wallbox adds more than 100 kWh.
How long does charging from a household socket take?
A household socket delivers 2.3 kW, i.e. 10 to 15 km of range per hour. A 60 kWh battery needs 25 hours to full. The socket is an emergency solution, not a daily one.
Does a 22 kW wallbox charge twice as fast as 11 kW?
Only for cars with a 22 kW on-board charger. Most EVs accept at most 11 kW AC and charge for the same time on both wallboxes.
Why does the car charge more slowly in winter?
A cold battery accepts less current and the car uses part of the energy to warm it. On slow AC charging the effect is small; on DC fast charging the power can halve.
Why does charging above 80 % take so long?
The battery management reduces current to balance and protect the cells. On DC the drop is dramatic, which is why road-trip charging stops at 80 %. At home overnight it does not matter.
How long does a plug-in hybrid take to charge?
Plug-in hybrids have 10 to 20 kWh batteries and a 3.7 kW charger, usually single-phase. A full charge takes 3 to 5 hours on any wallbox.