Direct Answer
Load balancing is a control function that lets an EV charger automatically reduce its charging current when the building's total electricity demand rises, and increase it again when demand falls. For homes and small sites, this is usually what makes a higher-power charger practical, because the charger can be limited to the capacity the supply can actually support instead of being capped by the charger's own maximum rating. Whether load balancing is available depends on the charger model, the configuration, and how the site is wired and metered.
Key Takeaways
- A measurement point, usually a current transformer or CT clamp, or a compatible meter, monitors the incoming supply.
- The charger or a controller continuously reads the total load at that point.
- When total demand approaches a configured limit, the charger reduces charging current in steps.
- When demand drops, the charger restores current, up to its configured maximum.
- Static load limiting – a fixed maximum current is set at installation based on the site's supply. This is simple and reliable, but it does not react to real-time demand.
- Dynamic load balancing, or DLB – the charging current is adjusted continuously based on live measurements, so the charger can use spare capacity when the building is quiet and back off when other loads are active.
- Confirm the exact charger model and whether DLB is supported for that model and configuration.
- Confirm what measurement hardware is required and whether it is included or supplied separately.
Buyer Checklist
- A measurement point, usually a current transformer or CT clamp, or a compatible meter, monitors the incoming supply.
- The charger or a controller continuously reads the total load at that point.
- When total demand approaches a configured limit, the charger reduces charging current in steps.
- When demand drops, the charger restores current, up to its configured maximum.
- Static load limiting – a fixed maximum current is set at installation based on the site's supply. This is simple and reliable, but it does not react to real-time demand.
- Dynamic load balancing, or DLB – the charging current is adjusted continuously based on live measurements, so the charger can use spare capacity when the building is quiet and back off when other loads are active.
- Confirm the exact charger model and whether DLB is supported for that model and configuration.
- Confirm what measurement hardware is required and whether it is included or supplied separately.
Detailed Answer
Load balancing is sometimes described as dynamic load management or DLB. The idea is simple - the charger is no longer treated as an isolated appliance, but as one load among many on the same supply.
How it typically works -
Two common forms -
Either way, the purpose is the same - keep the total site load within a defined limit, typically the main fuse or the agreed supply capacity.
Key Industry Insights
For a homeowner or installer, load balancing can decide whether a wallbox is straightforward to install or requires a supply upgrade. A home with limited incoming capacity may not be able to run a high-power charger at full output at the same time as an oven, heat pump, or air conditioning. Load balancing addresses that conflict without requiring the owner to reduce charging power permanently.
For small sites — apartments, small offices, workshops, shops, guesthouses, and small fleets — the supply is usually shared across several loads and sometimes several chargers. Load balancing helps avoid tripping the main protective device and helps keep charging within the supply the site already has.
For installers and electrical contractors, load balancing is an installation enabler and a technical talking point, but it also adds configuration steps - the measurement point, communication path, and limits all need to be set correctly and documented.
For distributors and resellers, load balancing is one of the functions buyers ask about, especially in Europe, where local wiring rules, network operator requirements, and building constraints affect what can be installed. It is worth being able to explain the concept clearly — and being equally clear about which models and configurations actually support it.
For solar and energy storage customers, load balancing pairs naturally with the idea of using surplus PV generation for charging instead of exporting it, and with avoiding unnecessary grid import during peak periods.
FAQ
What is the difference between static and dynamic load balancing?
Static limiting sets a fixed maximum current at installation. Dynamic load balancing adjusts current in real time based on measured site demand. Static is simpler; dynamic uses available capacity more efficiently.
Do I need load balancing to install a 22 kW charger at home?
Not automatically. It depends on the incoming supply, existing loads, and local rules. Many homes are limited by single-phase supply, in which case a lower-power configuration or three-phase availability becomes the deciding factor. A qualified electrician should assess this.
Can two or more chargers share one supply?
It is possible in principle, but the limits must be coordinated across units, and the installation must be reviewed by a competent person. This is a design decision, not a plug-and-play one.
Does load balancing work together with solar?
Load balancing and solar self-consumption are related but distinct. Load balancing protects the supply limit; solar-related functions aim to use surplus generation. Whether a specific charger supports either function depends on the model and configuration.
How can a buyer tell if a charger really supports load balancing?
Ask for the specification sheet for the exact model, confirm what measurement hardware is required, confirm which communication method is used, and ask for the configuration documentation. Model-level confirmation is more reliable than a general product description.
Does load balancing replace a proper electrical assessment?
No. It manages demand within a supply limit. It does not substitute for correct wiring, protection, earthing, or local compliance checks.
What happens if the measurement signal is lost?
Behaviour in fault or communication-loss conditions should be confirmed per model, because different designs handle fallback differently. This is a good question to put in writing before an order.