Plan on about 20 kWh stored in the first hour — roughly 10 kWh of it in the first half hour — and less per hour after that. A 22 kW DC charger runs at its best while the battery is low; as the battery fills, the car tapers the rate down, so the honest planning window is 20% to 80%, not empty to full. The numbers below are labelled examples at a sustained 22 kW with about 10% losses; real sessions bend away from them as taper bites.
Key Takeaways
- At 22 kW DC, plan on about 10 kWh stored per half hour early in a session and about 20 kWh in the first hour, before taper.
- The useful window is roughly 20% to 80%; the tail toward 100% is slow at any DC power.
- Your car’s DC acceptance, battery size and temperature bend every figure — the dashboard’s settled estimate is the number to trust.
- This is compact DC for parked stops, sized below the DOT’s 50–350 kW fast band.
The First Hour, Fifteen Minutes at a Time
One worked example: a car that accepts the full 22 kW DC, arriving low, in mild weather. The point is the bend — stored energy does not grow in a straight line:
| Time plugged in | Roughly stored by then | What is happening |
|---|---|---|
| 15 minutes | About 5 kWh | Full rate — the battery is low and asking for everything |
| 30 minutes | About 10 kWh | Still near full rate inside the 20–80% window |
| 45 minutes | About 14 kWh | On many cars the rate begins easing as the charge climbs |
| 60 minutes | About 17–18 kWh | Taper trims the hour’s average — the hour stores less than 22 kWh |
A car whose DC acceptance is below 22 kW stores proportionally less, and a cold battery starts slower until it warms. Treat the table as a planning sketch; trust your dashboard’s settled estimate — how fast a DC fast charger is explains the rate curves behind it.
Plan Around 20% to 80%, Not Empty to Full
DC charging has a fast middle and a slow tail. The last stretch toward 100% tapers so heavily that it can take about as long as the useful middle did — at any charger’s size:
- Arrive low. The charger does its best work early in the session; arriving at 20% buys more energy per minute than arriving at 60%.
- Leave at about 80%. Past that point you are paying time for the session’s slowest kilowatt-hours. Fill to 100% on overnight AC instead.
- Charge what the next leg needs. Enough to reach the next stop or home, plus a margin — not a full battery for its own sake.
Turning Kilowatt-Hours Into Your Day
Energy is the charger’s unit; miles are yours. As labelled arithmetic, at an example consumption of 0.30 kWh per mile: about 10 kWh stored works out near 33 miles, and the first hour’s roughly 20 kWh near 65 miles. Your car’s real efficiency — weather, speed, load — moves both figures, so use them to size a stop, not to promise an arrival. The same energy on AC takes far longer in most cars (their onboard chargers cap the session): charging times at 7 kW, 11 kW and 22 kW works the AC side.
The Unit Behind These Numbers
These examples are built on the EV-RHDC30K-L: 22 kW DC on its product page, a floor-standing single-connector charger with an LCD that shows the session, OCPP 1.6J, and an IP54 enclosure. Its listing does not name the DC connector standard fitted, so check your inlet matches before relying on a site, and confirm the variant in writing before ordering. EVDANCE is a Shenzhen manufacturer founded in 2011; the unit carries its 3-year standard warranty.
Frequently Asked Questions
How long does 20% to 80% take on a 22 kW DC charger?
Sixty percent of a mid-size battery is roughly 25–40 kWh, and at this unit that is about one and a half to two hours once taper is allowed for — less for a small battery, more for a large one. Most drivers take the first hour’s fast energy and go.
Why did the charging rate drop during my session?
That is taper, and it is the car protecting its battery, not a fault. As the battery fills, the car asks for less power. It is also why the top of the battery is the wrong place to plan a quick stop.
Is this as fast as a motorway fast charger?
No. The U.S. DOT puts DC fast charging at 50–350 kW, and this unit sits below that band by design. It is the charger for a stop where you are parked anyway — a meal, an errand, a workplace hour — not for a journey break.
Related Reading
- How Fast Is a DC Fast Charger?
- How Long Does It Take to Charge an EV at 7 kW, 11 kW and 22 kW?
- How Do DC Fast Chargers Work?
- Level 1 vs Level 2 vs DC Fast Charging: A Practical Comparison
