A dual-port DC charger feeds two connectors from one power source, and power sharing is how that source is divided. A car charging alone can draw up to its port’s peak rating; when both ports are in use, the unit splits its total simultaneous output between the two sessions — either as a fixed division or dynamically, following what each car can take. The number that decides what a second car actually gets is the simultaneous total, not the headline peak.
Key Takeaways
- A dual-port DC charger has one power source; the simultaneous total, not the per-port peak, decides two-car performance.
- Static designs reserve fixed shares; dynamic designs move unused power to the car that can take it.
- Each car is also capped by its own acceptance, whatever the allocation.
- Confirm the simultaneous total and allocation behaviour in writing before relying on them.
Two Numbers on Every Dual-Port Spec Sheet
Dual-port units are advertised with the bigger of two numbers. Both matter, and they answer different questions:
| Spec-sheet figure | What it means | What it decides |
|---|---|---|
| Per-port peak | The most one connector can deliver, with the other port idle | Your best-case speed when you charge alone |
| Simultaneous total | The most both ports can deliver added together | What is actually available when two cars charge at once |
| Allocation behaviour | How the total is divided — fixed split, or dynamic following each car’s demand | Whether a finishing or slow car releases power to yours |
Our explainer of what a dual port EV charger is covers the hardware itself. The reading skill is this: if the simultaneous total is well below twice the per-port peak, the peak is a one-car figure.
Static Split vs Dynamic Sharing
Two allocation designs are used. Under a static split, the total is reserved in fixed shares: each port holds its share whether its car can use it or not. Under dynamic sharing, the unit follows demand: a car that asks for less releases the difference to the other port, up to the total.
An example shows the arithmetic — the figures are illustrative only, not a product rating. Take a unit with a 120 kW simultaneous total and a 120 kW per-port peak. On a fixed split, each port is reserved 60 kW: a car that can only take 40 kW leaves 20 kW idle on its side. On a dynamic design, that same pair could run at 40 kW and 80 kW, because only the total binds. Either way, each car is also capped by its own acceptance: as how DC fast chargers work explains, the car directs what it draws.
What Changes During a Session
- A second car arrives. On a dynamic unit your rate steps down as the newcomer ramps up; on a fixed split your reserved share is unchanged — but it was capped from the start.
- The other car tapers. Every EV slows as its battery fills. On a dynamic unit, the freed capacity moves to your session; on a fixed split, it waits unused.
- The other car leaves. The full total returns to the remaining port, up to its peak and the car’s own limit.
Sharing is an operator’s design choice, not a fault: one supply serves two bays — the same principle examined in whether load balancing increases charging speed.
What EVDANCE Sells in This Space
Plainly: EVDANCE does not sell a dual-port DC charger, and its DC unit shares nothing because it serves one car. The EV-RHDC30K-L is a compact all-in-one DC charger of 22 kW, with OCPP 1.6J and an IP54 enclosure — a single-connector unit for sites whose demand and supply suit compact DC. On the AC side, the EV-AC03201T dual-connector AC station lists dynamic allocation across its two Type 2 connectors, up to 43 kW shared; how any shared unit divides power moment to moment is a behaviour to confirm with the manufacturer in writing before a site plan relies on it. The wider range is on our commercial charging page.
Frequently Asked Questions
Does a second car always halve my charging speed?
No. Your rate only falls if the two cars’ combined demand passes the simultaneous total. If the other car is tapering or has a modest limit, a dynamic unit may leave your session untouched.
Is a dual-port charger the same as two separate chargers?
No. Two separate chargers have two supplies and two independent totals. A dual-port unit has one supply and one combined ceiling, which is why it costs and installs differently.
Which sharing design should a site choose?
It depends on the site’s dwell pattern and vehicle mix. Ask for the simultaneous total and the allocation behaviour in writing, and judge the unit on those, not on the per-port peak alone.
Related Reading
- What Is a Dual Port EV Charger? How It Works and How to Choose
- How Do DC Fast Chargers Work?
- Does Load Balancing Increase EV Charging Speed?
- How Fast Is a DC Fast Charger?
