Why kWh price alone is not enough
If you are comparing the electric car charging cost of home charging versus public charging, the advertised price per kWh is only the starting point. Two sessions that both show “HUF per kWh” can end up with very different real costs because of charging losses, minimum session fees, connector type, and the state of charge (SOC) range you actually use.
For Hungarian drivers considering EV ownership, this matters a lot. Home charging can be very affordable, but public AC and especially DC charging may cost significantly more once you include service fees or higher peak tariffs. That is why an EV charging calculator is useful: it helps you estimate the real session cost instead of relying on a simple sticker price.
Quick freshness note: public charging tariffs and home electricity plans can change often, so always check the current rate before you compare options. The examples below are illustrative and meant to show the method, not a fixed market price.
SOC window explained
SOC means state of charge, or how full the battery is. The SOC window is the range you charge between, for example from 20% to 80%. This is important because most drivers do not charge from completely empty to completely full every time.
Why does this matter for cost? Because the amount of energy you need is based on the usable part of the battery, not the full battery capacity. If your EV has a 60 kWh battery and you charge from 20% to 80%, the battery accepts about 36 kWh at the pack level. If you charged from 10% to 90%, it would be about 48 kWh.
In practice, the SOC window also affects charging speed and efficiency:
- Low SOC to mid SOC is usually the fastest and most efficient part of charging.
- High SOC often slows down, especially on DC fast chargers.
- Top-ups from 40% to 70% may be cheaper and faster than trying to fill to 100%.
For everyday use, many EV owners plan around a 20%–80% window. That is a good balance between convenience, battery care, and cost predictability.
Charging loss explained
Charging losses are the energy that comes from the grid but does not end up stored in the battery. Some of it is lost as heat, and some is used by the car’s onboard systems or the charging equipment. This is why your electricity meter may show more kWh than the battery actually gains.
Typical losses depend on the setup:
- Home AC charging: often around 8% to 15% loss, depending on charger efficiency, cable, temperature, and battery condition.
- Public AC charging: similar to home AC in technical terms, but the total cost may be higher because of service fees or parking fees.
- DC fast charging: can be efficient at the charger level, but the battery and cooling systems may create different loss patterns, especially at high power or near the top of the battery range.
Example: if your battery needs 30 kWh of stored energy and your charging losses are 10%, the grid must supply about 33.3 kWh. If electricity costs HUF 70/kWh at home, the energy-only cost is roughly HUF 2,331 instead of HUF 2,100. That difference grows as the session gets larger.
This is why the real electromos autó kWh költség should be calculated from the energy drawn from the grid, not just the energy that ends up in the battery.
Home vs public charging examples
1) Home charging example
Let’s say you charge at home overnight on a wallbox, and your electricity rate is HUF 68/kWh. You want to move from 25% SOC to 75% SOC on a 64 kWh battery.
- Usable battery energy in that window: 64 kWh × 50% = 32 kWh
- Assume 10% charging loss: 32 kWh ÷ 0.90 = 35.6 kWh from the grid
- Session cost: 35.6 × HUF 68 = about HUF 2,421
That is a realistic estimate of the otthoni autótöltés ára when you include losses. If your home tariff is lower at night, the cost may be even better. If you charge from a standard socket instead of a dedicated wallbox, losses can be higher and the session can take much longer.
2) Public AC charging example
Now compare that with a public AC charger at HUF 130/kWh, plus a small session fee of HUF 200. Using the same 25% to 75% SOC window and the same 10% loss:
- Grid energy: 35.6 kWh
- Energy charge: 35.6 × HUF 130 = HUF 4,628
- Plus session fee: HUF 200
- Total: about HUF 4,828
Even though the charging method is technically similar to home AC charging, the public price is much higher. This is why comparing only the kWh rate is not enough; fixed fees can change the final cost materially.
3) DC fast charging example
DC charging is convenient on long trips, but it is usually the most expensive option. Suppose a fast charger costs HUF 180/kWh and you only charge from 20% to 60% on a 64 kWh battery because the charging curve slows down above that point.
- Usable battery energy: 64 kWh × 40% = 25.6 kWh
- Assume 8% loss: 25.6 kWh ÷ 0.92 = 27.8 kWh from the grid
- Session cost: 27.8 × HUF 180 = about HUF 5,004
Notice that the SOC window is narrower here. That is common on road trips: you often charge only enough to reach the next stop, not to 100%. Even with a smaller energy amount, the higher price per kWh makes DC sessions costly.
How to calculate session cost
If you want a quick estimate of EV charging cost, use this simple formula:
Session cost = Grid kWh × price per kWh + fixed fees
To find the grid kWh, start from the battery energy you want to add, then adjust for charging losses:
Grid kWh = battery kWh added ÷ charging efficiency
For example, if you want to add 20 kWh to the battery and your charging efficiency is 90%, the grid needs to supply about 22.2 kWh. At HUF 85/kWh, that is HUF 1,887 before any parking or session fees.
If you are comparing different charging scenarios, it helps to use the same assumptions each time:
- Battery size
- Starting SOC and target SOC
- Home, public AC, or DC charger
- Charging efficiency or loss percentage
- Any fixed fee, connection fee, or idle fee
For broader vehicle cost planning, you may also want to compare charging with other driving expenses using our ownership cost calculator or estimate daily travel cost with the commute cost calculator. If you are still comparing fuel and electricity for your next vehicle, the fuel cost calculator can help with that side-by-side view too.
Calculator CTA
Electricity prices, charging losses, and SOC windows can change the real cost more than many drivers expect. If you want a faster and more accurate estimate for your own EV, use the EV charging calculator to compare home charging, public AC, and DC charging in one place.
Try the calculator now to estimate your next charging session cost.