The first thing many people are told when they ask about a home charger is that they will need to increase their contracted power. Sometimes that is true. Far more often it is an unnecessary and permanent expense, and there is a straightforward alternative.
What is the actual problem?
Contracted power is the ceiling on what your property can draw at any one instant. Exceed it and the control device cuts your supply — everything goes off, and you reset it.
A typical Spanish home is contracted at a level chosen years ago for a household without an electric car. Add a charger drawing 7.4 kW continuously in the evening, on top of an oven, an induction hob, a water heater and air conditioning, and you can be over the limit. That is a real constraint, not a sales tactic.
What is dynamic load management?
It is a current sensor fitted on your incoming supply that tells the charger, continuously, how much the rest of the property is using. The charger then draws only what is left below your contracted limit.
In practice: you start cooking, the charger quietly reduces its rate; you finish, and it goes back up. The car charges more slowly during the busy hour or two of the evening and at full rate for the rest of the night. You never exceed your contracted power, and the main switch never trips.
It is a small piece of hardware and a setting, fitted at the same time as the charger. There is nothing to operate and nothing to remember.
Why is it usually the better answer?
Because of what the alternative costs, and for how long.
Increasing your contracted power raises the fixed part of your electricity bill for every month you live in the property, whether or not you are charging. You pay it in February when the car is barely used and in August when you are away. What you get in exchange is a faster charge on the handful of evenings when the whole house happens to be at full load at once.
The sensor is a one-off cost that removes the same problem. For a car parked overnight, the two produce nearly identical outcomes, because a derated charge over twelve hours still adds far more range than a normal day uses.
The arithmetic
Suppose your daily driving is 50 km. That is roughly 8 to 10 kWh to replace.
At full 7.4 kW that takes a bit over an hour. Even if load management holds the charger down to a third of its rate for three hours of a busy evening and then releases it, you have the whole rest of the night at full rate. The car is full long before morning either way.
The gap between the two approaches only becomes real when the available window is short or the demand is large. That is the exception, not the rule.
When you genuinely do need more power
Three cases, and we will tell you if you are in one of them.
Two electric cars charging on the same supply, where the total demand is high and the hours are shared.
A property that already runs close to its limit before the car — commonly one with electric heating or a heat pump, an induction hob, and a pool pump on the same supply.
A car that has to be fully charged in a short, fixed window rather than overnight, which usually means a vehicle in commercial use.
How to find out which you are
Look at your bill for your contracted power, then think about what actually runs at seven in the evening in your house. If the honest answer is that the oven, the hob and the air conditioning are frequently all on at once and you are already close to the limit, an increase may be justified.
For everyone else, the sensor solves it. We read the meter and the board before quoting precisely so this decision is made on your actual numbers rather than as a default, because it is the one choice in the whole installation that costs you money every month for years if it is made wrongly.
