The right retail charger is sized to the stop, not to the motorway. Where customers park 30 to 60 minutes, a compact DC charger at a sustained 22 kW stores roughly 10 kWh per half hour and about 20 kWh per hour, before taper. That is the job of the EV-RHDC30K-L: a floor-standing, single-connector DC unit rated 22 kW on its product page.
Key Takeaways
- A 30–60 minute retail stop stores roughly 10–20 kWh at a sustained 22 kW DC, before taper and the car’s own limits.
- DC wins the short stop because conversion in the station bypasses the car’s onboard AC limit.
- If your real dwell runs to two hours or more, AC serves the same cars more lightly — measure your own dwell first.
- One connector means one car at a time; confirm the fitted DC connector in writing before ordering.
The Energy a Shopping Stop Can Hold
Work in energy, not percentages: the battery holds kilowatt-hours, and at the station’s ceiling the arithmetic is simple:
| Stop length | Energy drawn at a sustained 22 kW | Roughly stored, allowing ~10% losses |
|---|---|---|
| 30 minutes | 11 kWh | About 10 kWh |
| 45 minutes | 16.5 kWh | About 15 kWh |
| 60 minutes | 22 kWh | About 20 kWh |
These are ceiling figures, and two things pull real sessions below them. DC charging tapers as the battery fills, so the last part of a session runs slower than the first; and the car’s own DC acceptance caps it further — a car that accepts less than 22 kW DC takes less, whatever the charger offers. Treat the table as the best case — a car arriving with room in its battery — not a promise to every driver.
Why DC Fits This Dwell Better Than AC
An AC post in the same bay faces a different limit: the car’s onboard charger. Cars whose AC acceptance is 7 kW or 11 kW store at that rate all session, no matter what the post can offer — over a 45-minute shop, roughly 5 to 8 kWh. With DC, conversion happens in the station, so the rate is set by the station and the car’s DC acceptance. In a short stop, the bypass is worth more than headline power; how DC fast chargers work explains the conversion in full.
The Honest Fit Test
Compact DC earns its place only where the dwell is short. Run the test on your own car park before buying:
- Measure your real dwell. Your entry and exit data says how long cars stay; that number, not a published average, decides the charger class.
- If stays run to two hours or more — a leisure- or cinema-led centre — AC destination charging fills the same cars over the longer stay with lighter infrastructure. DOE-cited U.S. figures (about $3,500 equipment plus $2,500 installation per Level 2 connector) show the lighter structure — U.S. context, not a quote for your site.
- If stays cluster at 30–60 minutes, turnover is the product, and the DC window above is what buys it.
Our guide to EV charging for restaurants and retail covers the dwell-time side.
The EV-RHDC30K-L in a Retail Car Park
The EV-RHDC30K-L is a floor-standing DC charger: 22 kW on the product page (the range notes describe the class as 22 kW DC), a single connector, an LCD, and an IP54 enclosure for outdoor car parks. It speaks OCPP 1.6J, so sessions run through your charging platform; access and pricing are your platform arrangements. Two honest notes. One connector charges one car at a time, so signing the bay and keeping stops short is part of the installation. And the listing does not name the DC connector standard: confirm in writing, before ordering, that the fitted connector matches the cars your customers drive.
Frequently Asked Questions
Is 22 kW really “fast charging”?
It sits below the U.S. DOT’s 50–350 kW DC fast band, so call it what it is: compact DC. It is faster than AC for most cars because conversion happens in the station, sized for a shopping stop, not a journey break. How fast a DC fast charger is depends on the class — this one trades peak speed for a supply and footprint a retail site can host.
How much range does a 30-minute stop add?
Range is the car’s arithmetic, not the charger’s rating. As a labelled example only: at 0.30 kWh per mile, about 10 kWh stored works out near 33 miles. Cold weather and a high starting charge move the real figure; the car’s own display is the number to plan around.
How many units does a retail car park need?
One connector serves one car at a time, so the count follows your peak turnover: how many drivers per hour would use it on your busiest day. Start there and add units as the queue proves itself.
Related Reading
- EV Charging for Restaurants and Retail: Turning Dwell Time Into Visits
- Level 1 vs Level 2 vs DC Fast Charging: A Practical Comparison
- How Fast Is a DC Fast Charger?
- How Do DC Fast Chargers Work?
