Load management without vendor lock-in
Your charge points. Your vendors. Your load management.
The limit is the building's connection, not the charge point — and not the brand on the wallbox. How your aCharge controller turns whatever power is actually spare into as many charging sessions as possible: vendor-independent, without tripping the fuse and without a grid upgrade.
“Two makes in one car park — and one system's load management cannot see the other's charge points.”
That is the normal case as soon as a site is extended: the existing wallboxes come from one manufacturer, the new ones from another, and the two systems regulate past each other. Staying vendor-locked at that point means either replacing half the installation or sizing it for the worst case all over again.
Do the maths for the worst case once
Six 11 kW wallboxes together want 66 kW. A typical 63 A house connection provides around 43 kW — and the building itself already takes a share of that. Without control, the installation has to be sized for the worst case: every charge point at full power simultaneously.
That leaves two options: an expensive grid upgrade, or fewer charge points. Dynamic load management is the third.
Example site
- Charge points
- 6 × 11 kW
- Theoretical demand
- 66 kW
- House connection
- 63 A ≈ 43 kW
- Shortfall
- −23 kW
Those 23 kW are exactly the difference between “not possible” and “possible, with control”.
Fundamentals
What is dynamic load management?
Every building has one hard ceiling: its grid connection. Put together, charge points almost always want more than that ceiling allows. Dynamic load management solves this with metering and software instead of an expensive grid upgrade — it measures what the site actually draws, works out how much capacity is left, and hands that out to the vehicles. Second by second, all day long.
- Six charge points want
- 66 kW
- The connection delivers
- 43 kW
- Below this current no car charges
- 6 A
The cable is the bottleneck
A typical 63 A commercial connection delivers around 43 kW. Six 11 kW wallboxes want 66 kW — more than the connection can give. Without control the main fuse trips, or a grid upgrade runs into five figures.
Static: safe, but wasteful
Static load management reserves a fixed budget for the charge points — sized against the building's peak load so it is safe at every hour. It works, but in the evening, when the building draws almost nothing, 30 kW sit unused in the cable.
Dynamic: the leftovers, in real time
The controller measures the real draw at the building's supply point and releases exactly what is spare to the charge points. When the building load rises, the vehicles throttle back. When it falls, they charge faster. The connection limit is never exceeded — and never needlessly left unused.
Interactive simulation
One day at an example site
6 charge points at 11 kW each on a 43 kW connection. Switch the strategy and watch what happens to the site.
No control: Every vehicle pulls whatever it can. The cars do get full — but the grid draw shoots far past the connection limit. In reality, this is where the main fuse trips.
Static: A permanently reserved budget of 10 kW, sized for the building's peak load. Safe at every hour — but it only stretches to two vehicles at a time, and in the evening the free capacity goes unused.
Dynamic: The budget is whatever the connection has spare right now. At midday, under full building load, charging throttles back; in the evening everyone charges at full power — without ever touching the limit.
At the connection now
- Building
- 0 kW
- PV
- − 0 kW
- Charging
- 0 kW
- Grid draw
- 0 / 43 kW
- Spare
- 0 kW
Connection limit exceeded by 0 kW
Grid operator throttling: max. 4.2 kW for controllable loads
Van · deliveries
06:00 – 14:00 · 75 kWh
Company car · field sales
07:00 – 17:30 · 60 kWh
Employee A
08:00 – 17:00 · 52 kWh
Employee B
08:30 – 16:00 · 40 kWh
Visitor
10:00 – 12:30 · 58 kWh
Pool vehicle · late shift
16:00 – 21:00 · 80 kWh
| Strategy | Delivered | Avg. state of charge on departure | Vehicles ≥ 80 % | Peak grid draw | Over the limit |
|---|---|---|---|---|---|
| No control | — kWh | — | — | — | — |
| Static | — kWh | — | — | — | — |
| Dynamic (DYLAMO) | — kWh | — | — | — | — |
Simplified simulation using example values: 63 A connection (≈ 43 kW), six 11 kW charge points, a typical commercial load profile and six vehicles with different dwell times. Real sites are dimensioned individually.
Under the hood
Four steps, every second
Measure
A meter at the building's supply point reports actual real power — per phase, continuously. Not the number on the datasheet, but what is genuinely flowing right now.
Compute
The controller subtracts that from the contracted connection capacity. Whatever is left is the free budget — plus whatever the PV system is generating on site.
Distribute
The budget is split across the occupied charge points — by priority, dwell time and state of charge. Never below 6 A per vehicle, because below that no car charges at all.
Fail safe
The controller regulates locally, not in the cloud. If the internet connection drops, load management carries on unchanged and re-syncs automatically once it returns.
When one dimension is no longer enough
Simple dynamic load management tracks one quantity: the spare capacity at the connection. At larger sites, though, other loads and generators hang off the same cable — and they move that budget constantly. DYLAMO factors all of them in rather than ignoring them.
- On-site PV generation
- Heat pumps
- Transformer load
- Charge points from multiple vendors
- Priority and dwell time per vehicle
- Vehicle battery state of charge
When the grid operator throttles
Since 2024, German grid operators may temporarily throttle controllable consumers — wallboxes, heat pumps, batteries — down to 4.2 kW when the grid is at risk of overload, in exchange for reduced grid fees. The aCharge Controller accepts that signal and still allocates even the reduced budget by priority, rather than hard-stopping charge points.
Try the “Grid operator dimming” switch in the simulation above — it throttles the evening peak from 17:00 to 20:00.
More charge points on the same connection
The economic core of dynamic load management is not the technology but what it avoids: a bigger grid connection. Instead of sizing the cable for a theoretical worst case where everything runs at once, the existing connection is used as far as it safely allows — and the site can grow without the excavators coming back.
In your installation
What your aCharge controller makes of it
The simulation shows the principle. On a real site three things come on top — the difference between a control loop and an operation.
It keeps running when the line drops
The controller regulates locally. If the internet connection fails, it keeps enforcing the site capacity unchanged and re-synchronises with the cloud afterwards — sessions and meter readings are not lost.
It does not matter who built the wallbox
Charge points are connected over OCPP or Modbus TCP — mixed within the same installation if need be. You are not tied to one vendor and can add whatever is available later.
The grid operator gets a say
On a § 14a EnWG control signal the controller reduces power to the permitted level instead of switching off. Every event is logged and stays auditable.
Technical
What can be connected
Charge points, generators and loads in one budget — regardless of who built them.
- Charge point protocol
- OCPP 1.6 · 1.6 Security · 2.0.1
- Fieldbus
- Modbus TCP
- Vendors
- mixed vendors in one installation
- Charging hardware
- AC and DC
- Control
- local on the controller, works offline
- Power control
- dynamic, multi-dimensional
- § 14a EnWG
- grid-serving control instead of shut-off
- PV system
- surplus charging
- Heat pump
- included as a controllable load
- Transformer
- included as a measuring point
- Grid connection
- limit enforced in real time
- Scale
- up to 1,000 charge points per site
What section 14a EnWG requires
Controllable devices, minimum power, reduced grid fees — and why an energy management system makes the intervention bearable.
PV surplus charging
Charging on the solar power that would otherwise be exported — and the 1.4 kW floor it hangs on in practice.
Frequently asked