FAQ – Electric Mobility: What Installers Need to Know
With the expansion of electric mobility, more and more customers are seeking efficient charging solutions for their homes, businesses, and fleets. For electrical professionals, it is essential to understand the key points that guide the selection and installation of chargers.
18 August 2025
1. How to choose the right charger for each installation?
The decision should consider three main factors:
The decision should consider three main factors:
- Vehicle capacity: each car has a limit for AC charging. It makes no sense to install a 22 kW charger in a location where the vehicle only accepts up to 7.4 kW, since the extra power will not be used.
- Electrical availability of the site: check the contracted power and the condition of the existing installation. In many homes, a single-phase installation is sufficient for regular charging needs.
- Usage profile: customers with short daily commutes may opt for single-phase chargers from 3.7 to 7.4 kW. In business contexts or when faster charging is needed, three-phase solutions of 11 or 22 kW may be justified.
2. Difference between single-phase and three-phase chargers
Single-phase: common in homes, allowing up to 7.4 kW. They require only one phase of the grid, and installation is generally simpler.
Three-phase: allow higher power (11 to 22 kW), provided a three-phase grid is available. They are suitable for buildings, businesses, and locations where multiple vehicles need charging or faster charging times are desired.
Note: not all vehicles support three-phase AC charging, so it is essential to verify this information before installation.
Single-phase: common in homes, allowing up to 7.4 kW. They require only one phase of the grid, and installation is generally simpler.
Three-phase: allow higher power (11 to 22 kW), provided a three-phase grid is available. They are suitable for buildings, businesses, and locations where multiple vehicles need charging or faster charging times are desired.
Note: not all vehicles support three-phase AC charging, so it is essential to verify this information before installation.
3. What is the difference between AC and DC charging, and when to use each?
Electric vehicle charging can be done with alternating current (AC) or direct current (DC), and the choice depends on available power and the type of installation:
AC Charging (Alternating Current)
AC → Ideal for homes and small businesses, more economical and easy to install.
DC → Only for public stations or fleets requiring fast charging, due to cost and power requirements.
Electric vehicle charging can be done with alternating current (AC) or direct current (DC), and the choice depends on available power and the type of installation:
AC Charging (Alternating Current)
- Energy arrives as AC; the vehicle converts it to DC internally.
- Typical power: 3.7 kW to 22 kW (single-phase or three-phase).
- Advantages: simpler and more economical installation, compatible with most vehicles, allows integration with time-of-use tariffs.
- Limitation: slower charging compared to DC.
- The charger converts AC to DC before sending it to the battery, enabling fast charging.
- Typical power: 50 kW to 350 kW (public stations or fleets).
- Advantages: very short charging times, ideal for public stations or fleets needing immediate availability.
- Limitations: more expensive equipment, requires a robust electrical installation, rarely used in homes.
AC → Ideal for homes and small businesses, more economical and easy to install.
DC → Only for public stations or fleets requiring fast charging, due to cost and power requirements.
4. What is load balancing?
Load balancing is a feature that automatically regulates the charger’s power according to the available electrical installation capacity.
How it works: it monitors the total consumption of the installation, adjusts the power supplied to the vehicle, and restores full power when consumption decreases.
Example: if high-power equipment is operating (oven, air conditioning, industrial machines), the system temporarily reduces charging power to prevent circuit breakers from tripping.
Advantages: prevents overloads, maximizes the use of contracted power, and allows the installation of multiple charging points without immediately upgrading the electrical system.
Load balancing is a feature that automatically regulates the charger’s power according to the available electrical installation capacity.
How it works: it monitors the total consumption of the installation, adjusts the power supplied to the vehicle, and restores full power when consumption decreases.
Example: if high-power equipment is operating (oven, air conditioning, industrial machines), the system temporarily reduces charging power to prevent circuit breakers from tripping.
Advantages: prevents overloads, maximizes the use of contracted power, and allows the installation of multiple charging points without immediately upgrading the electrical system.
5. Can I install a high-power charger if the electrical installation or contracted power is insufficient?
Even if the vehicle supports fast or three-phase charging, the charger’s power is limited by the capacity of the installation and the contracted power. Installing a high-power unit without prior assessment can cause overloads, circuit breaker trips, or safety risks.
Recommendations:
Even if the vehicle supports fast or three-phase charging, the charger’s power is limited by the capacity of the installation and the contracted power. Installing a high-power unit without prior assessment can cause overloads, circuit breaker trips, or safety risks.
Recommendations:
- Always assess the available power at the electrical panel and the contracted power.
- Consider load balancing solutions if there are other significant electrical loads.
- Plan to upgrade the installation or contracted power when necessary.
- Verify compatibility between the charger’s power and the vehicle’s maximum charging capacity.
6. Can I install a fast charger even if the vehicle does not support high power?
It is not efficient. The charger will only operate up to the maximum power the vehicle can accept, making the investment in extra power unnecessary.
It is not efficient. The charger will only operate up to the maximum power the vehicle can accept, making the investment in extra power unnecessary.
7. Can I install a high-power charger near an old electrical panel?
It depends. Older panels may not support the required currents. Check the capacity of circuit breakers, busbars, and conductors before installation.
It depends. Older panels may not support the required currents. Check the capacity of circuit breakers, busbars, and conductors before installation.
8. Can I install a charger without planning for measurement or monitoring points?
It is possible, but not recommended. Measurement and monitoring allow you to optimize charging, manage energy costs, and quickly identify issues in the installation.
It is possible, but not recommended. Measurement and monitoring allow you to optimize charging, manage energy costs, and quickly identify issues in the installation.
Installer Support
For installers, panel builders, and electrical industry professionals, Nortécnica provides a range of resources to make electric vehicle charger installations safer, more efficient, and tailored to customer needs:
- Personalized consultancy: assessment of the electrical installation and selection of the appropriate charger.
- Technical training: on electric mobility, load balancing, and monitoring.
- Certified products: chargers suitable for homes, businesses, and fleets.