EV charger dynamic load balancing in Seville, Spain: charge the car without raising your potencia

EV charger dynamic load balancing: what it is and why you almost always need it

Almost every home in Seville has a single-phase supply, and contracted powers (potencia contratada) of 4.6 or 5.75 kW are very common. A 7.4 kW electric car charger on its own already exceeds those figures. Add the oven, the induction hob or the air conditioning in August and the power control switch (ICP, now built into the smart meter) cuts out and you are left in the dark.

If you come from the UK or the US, this is the part of the Spanish system that surprises people most: your home does not simply draw what it needs, it is capped at the kW you pay for each month. Dynamic load balancing for your wallbox avoids that cut. A meter (a current clamp or a meter with Modbus communication) is fitted where the supply enters your installation and tells the charger, second by second, how much the home is using. The charger adjusts its current so that home plus car never exceeds your contracted power. Charging adapts, but the lights stay on.

Charge your car without raising your potencia

With load balancing you can charge your car without increasing your contracted power in most cases. At night, when the home uses very little, the charger works close to its maximum. In the evening, if you are cooking or running the washing machine, it reduces charging and catches up later. The charging standard sets a minimum of 6 A (about 1.4 kW) so the car keeps charging.

If you drive a lot and want to charge faster, the 2.0TD tariff lets you contract a different power in the peak and off-peak periods. Many owners raise only the off-peak power, from 00:00 to 08:00 and all weekend, which is the cheapest, and keep load balancing as protection. If you still need more power at any time of day, we help you increase your contracted power with its boletín (the electrical installation certificate).

Cheap night-time charging

Load balancing works well with scheduled charging. From the charger or car app you set it to charge only in the off-peak period. With a price of 0.08 to 0.15 euros per kWh off-peak, charging costs around 1.8 euros per 100 km, compared with 9 to 11 euros in petrol (gas). For 15,000 km a year, that is about 20 to 30 euros a month of electricity.

What each manufacturer calls it

Almost all mid-range and high-end chargers accept load balancing with an external meter, although each brand gives it a different name:

• Wallbox: Power Boost for balancing against the home, and Power Sharing for sharing power between several chargers.
• V2C Trydan: dynamic meter, which also allows charging from solar surplus.
• Circutor eHome Link: version with built-in load balancing.
• Tesla Wall Connector: load balancing with a compatible external meter.

We explain the differences between models on our EV charger brands page.

How we install it

1. We review your contracted power and your real consumption, plus the charger model you have or are about to buy.
2. We fit the meter in the main fuse board or on the individual supply cable (derivación individual), depending on where your meter is.
3. We link meter and charger by cable or wirelessly. In garages with poor signal, a cable is the reliable option.
4. We set the maximum power and check with a real load that the power limiter does not trip when the heaviest appliances come on.
5. We show you the app to schedule charging and see your consumption.

Guide prices

If load balancing is fitted with the charger, it is included in the fixed quote for the charging point. All our rates are on the prices page.

Where it is essential

• In flats in Nervión, Los Remedios or Triana, in blocks from the 1960s and 1970s with low contracted power, where increasing power is not always possible without building work.
• In a communal garage, when the charger is fed from your flat meter and the space is far away: a trip means going upstairs to reset it. The technical guide to ITC-BT-52 specifically recommends load balancing in this case.
• In villas in Sevilla Este, Dos Hermanas or the Aljarafe with air conditioning, a pool and a heat pump: a house uses a lot of power in summer and load balancing shares it out.

If your ICP already trips often, read our page on what to do when the power limiter keeps tripping. You will find every other option on the EV charger installation page.