Guide
Load balancing: charge without overloading your installation.
An EV charger is often the largest load in a home. Load balancing lets the charger use only the capacity the house is not using, so you can charge without tripping the main breaker or upgrading the electrical service.
The problem: one service, many loads
Every home has a maximum current set by its electrical service and main breaker. The Bora 16 draws up to 16 A and the Bora 32 up to 32 A. Add an electric shower, the stove or air conditioning and the total can exceed the limit.
Without load balancing, the installation has to be sized for the charger at full power plus everything else at the same time, or the charger has to be set permanently to a low current.
How it works
The charger reads the main energy meter of the house, connected by Modbus RS485 or over Wi-Fi, to know how much current the house is drawing. With that information it continuously adjusts its own charging current so that the total stays below the limit you configure.
When the house uses little power, for example at night, the car charges at full power. When other appliances switch on, the charger reduces its current, and it increases it again when they switch off.
An example
Take a 50 A limit at 240 V and a Bora 32 set to that limit. The table shows how much current is left for the car as the household load changes.
| House load | Available for the car | Approx. charging power |
|---|---|---|
| 10 A | 32 A (charger maximum) | about 7.7 kW |
| 25 A | 25 A | about 6 kW |
| 40 A | 10 A | about 2.4 kW |
Below the minimum
AC charging works with a minimum current of about 6 A. If the spare capacity drops below that, charging typically pauses and resumes automatically when capacity is available again.
Do you need it?
Load balancing is most useful when capacity is limited, when there are large loads such as electric showers, stoves or air conditioning, or when you choose a Bora 32 on an installation that cannot always deliver 32 A.
It is also the simplest way to add a charger without upgrading the electrical service.
Load balancing on Bora chargers
Configurable load balancing is available as an option on the Bora 16 and Bora 32, and included on the Bora 32 Pro. The charger connects to the main meter by Modbus RS485 or Wi-Fi. Tell us your electrical service and meter and we will define the setup with you and your electrician.