Payback on a compact DC charger is an equation, not a brochure figure: your installed cost divided by your monthly net contribution. Sessions per day is the input that moves the answer most, and it is the one nobody can give you — it comes from your site, measured after opening. This article builds the model for a 22 kW unit like the EV-RHDC30K-L.
Key Takeaways
- Payback = installed cost ÷ monthly net contribution; every input is yours — quote, tariff, and measured use.
- Sessions per day is the swing input and the least predictable; model it as a range, then replace it with platform reports.
- Worked examples with invented figures show the model’s shape only — never carry another site’s numbers into your decision.
- Published DOE cost figures describe U.S. corridor-class DC installations, not a compact 22 kW unit’s installed cost.
The Model: Seven Inputs, All Yours
| Input | Where it comes from | Your figure |
|---|---|---|
| Installed cost | Your installer’s quote: unit, groundwork, connection, commissioning | Goes here |
| Tariff per kWh | Your pricing decision, set in your platform | Goes here |
| Sessions per day | Measured on your platform after a trial period — never a benchmark | Goes here |
| Energy per session | Measured: your drivers’ top-up pattern on a 22 kW unit | Goes here |
| Electricity cost per kWh | Your supply contract, including any demand element | Goes here |
| Platform and payment fees | Your platform agreement | Goes here |
| Maintenance per month | Your service arrangement, inside and beyond warranty | Goes here |
Monthly net contribution = (sessions per day × energy per session × (tariff − electricity cost) × days) − platform fees − maintenance. Payback in months = installed cost ÷ that contribution. Our overview of whether charging stations are a good investment covers the wider business judgement. U.S. DOE-cited figures put corridor-class DC fast charging at about $38,000–$90,000 equipment plus $20,000–$60,000 installation — U.S. context for a larger class, not a quote for a compact unit.
One Worked Example — Every Figure Invented
Every number in this section is invented for illustration — replace all of them. Suppose: installed cost €12,000; tariff €0.50 per kWh; measured use of 4 sessions a day averaging 18 kWh; electricity at €0.25 per kWh. Daily energy sold is 72 kWh, gross revenue €36, energy cost €18 — a contribution of €18 a day before platform fees and maintenance, roughly €540 a month, which repays the invented €12,000 in about 22 months. Sessions per day alone moves the same invented model to about 44 months at 2 a day and about 11 months at 8. That spread is the lesson: the payback period is mostly a statement about your site’s traffic, wearing a charger’s clothes.
Which Input Deserves Your Attention
Sessions per day moves the answer linearly and is the least predictable input, so model it low, base-case and high rather than as one number, and re-run the model on real platform reports after the first season. Tariff is yours to set but bounded by what your drivers will pay at your site. Energy per session on a 22 kW unit follows dwell — a workplace top-up and a retail stop deliver different kWh, and your reports will say which you have. Installed cost is the one input that stops moving once the unit is in. The unit reports its sessions over OCPP 1.6J to your platform, as our OCPP explainer for operators describes — the two measured inputs are recorded from day one.
The Unit in This Model
The EV-RHDC30K-L is a floor-standing compact DC charger: 22 kW per its product page, single connector, LCD display, IP54, OCPP 1.6J, and EVDANCE’s 3-year standard warranty. That compact size is why the model above must be fed your quote, not a published range for corridor hardware. Operators speccing a site can compare the wider commercial charging range before running their numbers.
Frequently Asked Questions
What payback period should I expect from a compact DC charger?
There is no typical figure. Payback is your installed cost divided by your measured monthly contribution; sites with identical hardware differ by years because their sessions per day differ. Build the model, then replace the estimates with your first season’s reports.
How many sessions a day does a 22 kW charger need?
Enough that the contribution covers your installed cost inside the horizon you set — the model above turns that sentence into a number for your site. A single connector can serve a session roughly every hour it is available, but demand, not capacity, is the binding input.
Can I use published DC charger costs in my model?
Only as context. Published DOE figures describe U.S. corridor-class installations, not a compact 22 kW unit on your site. Your installer’s written quote is the only installed-cost figure the model should carry.
Related Reading
- Are EV Charging Stations a Good Investment?
- Is an EV Charging Station Business Profitable?
- How Much Do EV Charging Stations Charge? Pricing Models Explained
- OCPP Explained: What Charge Point Operators Need From EV Charger Hardware
