“Give employees a charge card and it’s settled” — a common simplification. In practice, public charging is full of hidden costs that significantly increase the official kWh price. What to expect.

Hidden cost 1: roaming margin

When an employee with charge card X charges at a station from operator Y, there is a roaming margin involved — typically 5 to 25 cents per kWh extra on top of the station’s standard rate. On an average charging session of 30 kWh, that amounts to €1.50–€7.50 in invisible margin per session.

Hidden cost 2: idle fee

Many fast chargers charge a surcharge of €0.10–€0.30 per minute when a vehicle remains at the station after charging — to prevent vehicles from staying for hours. For an employee who plugs their vehicle into the fast charger at 12:30 PM and only returns at 2:00 PM after lunch: easily €15–€20 extra on top of the charging cost.

Hidden cost 3: session surcharge

Some operators charge a fixed fee per charging session (€0.50–€1.50). Harmless for a one-off, but with 3 sessions per week × 50 weeks = €75–€225 extra per employee per year.

Hidden cost 4: rate difference between apps and cards

The same station can charge different prices depending on the app or charge card used. Differences of up to €0.15/kWh are not exceptional. Employees who choose the most expensive option due to a lack of information incur hundreds of euros in unnecessary costs annually.

In concrete terms: annual hidden cost for a fleet of 50 EVs

Suppose: an average of 20% public charging = 1,500 kWh/vehicle/year = 75,000 kWh fleet total.

  • Roaming margin average €0.12/kWh: €9,000/year
  • Session surcharges 100/vehicle/year × €0.75: €3,750/year
  • Idle fees (estimated): €2,500/year
  • Total hidden cost: €15,250/year

That is €305 per vehicle per year, or €1.02 per liter petrol equivalent — on top of the official kWh price.

How to control these costs

  1. Choose one charge card provider with a transparent tariff structure and sufficient coverage — not three different ones.
  2. Establish an internal guideline: home charging where possible, public only while on the road, fast charging only when necessary.
  3. Monitor the share of public charging per employee monthly — outliers are usually the result of unfavorable charging habits, not necessity.

The structural alternative

The more you can shift to home charging stations + split billing, the less public charging and therefore fewer hidden costs. With 80% home charging, the average hidden cost per vehicle is halved.

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Would you like to see how much you could save on annual public charging costs? Schedule a consultation — our fleet specialist will break down the savings per scenario.